Animal Anatomy and Physiology

How are compounds and mixtures different from one another?

A compound includes two or more elements that are chemically bonded to one another via covalent or ionic bonds. The elements are present in a specific ratio, which is consistent for a particular compound.

Why do animals cough, sneeze, yawn, sigh, hiccup?

A cough is a protective reflex stimulated by irritation or foreign matter in the trachea or bronchi. Moist coughs, also known as productive coughs, help an animal clear mucus and other matter from the lower respiratory passages. They are generally beneficial to the animal, and we usually do not try to eliminate them with medications. Dry coughs, also known as nonproductive coughs, are generally not beneficial and are often treated with cough-suppressant medications. A sneeze is similar to a cough, but the irritation originates in the nasal passages. The burst of air is directed through the nose and mouth in an effort to eliminate the irritant or irritants. A yawn is a slow, deep breath taken through a wide-open mouth. It may be stimulated by a slight decrease in the oxygen level of the blood, or it may result from boredom, drowsiness, or fatigue. Yawns can even occur in humans by the power of suggestion, such as seeing someone else yawn or even thinking about yawning. (Did you just yawn?) A sigh is a slightly deeper-than-normal breath. It is not accompanied by a wide-open mouth like a yawn. A sigh breath may be a mild corrective action when the blood level of oxygen gets a little low or the carbon dioxide level gets a little high. It may also serve to expand the lungs more than the normal breathing pattern does. Anesthetized animals are often manually given deep sigh breaths periodically to keep their lungs well expanded. This is done to prevent the partial collapse of the lungs, which can occur in anesthetized animals as a result of respiratory system depression caused by general anesthetic drugs. Hiccups are spasmodic contractions of the diaphragm accompanied by sudden closure of the glottis, causing the characteristic "hiccup" sound. Although hiccups can result from serious conditions such as nerve irritation, indigestion, and central nervous system damage, most of the time they are harmless and temporary and occur for unknown reasons.

How does an ionic bond differ from a covalent bond?

A covalent bond is the bond formed when atoms share electrons. An ionic bond is formed when electrons are transferred from one atom to another.

What is a drink patch in reptiles and amphibians?

A drink patch is an area of the skin with increased permeability. It is usually present on the ventral surfaces that most frequently come in contact with water. The extremely permeable nature of amphibians' skin allows them to absorb all the water they need from the environment; thus amphibians do not drink.

Define a fault bar. What causes it?

A fault bar (stress bar) is a weakened area on the feather vane where the barbs lack barbules. If a feather is stressed during its growth, even for a few hours, there is an interruption in its blood flow and a fault bar develops. When the stressor is removed, the blood supply is returned and normal development continues. The most common stressor is a poor diet.

Which would likely be a greater threat to an animal's well-being: a fracture of the mandible or a fracture of the occipital bone? Why?

A fracture to the occipital bone would be a greater threat because the spinal cord exits the skull through this bone and because it articulates (forms a joint) with the first cervical (neck) vertebra. The occipital bone is one of many bones that house the brain. Damage to this bone could affect various functions of the central nervous system.

Define the term "functional group".

A functional group is the reactive part of a molecule that determines the molecule's chemical activity.

How does the negative feedback system control the secretion of many hormones?

A gland produces its hormone as a result of stimulation by another hormone. When the level of hormone from the first gland drops below needed levels, the second gland, the stimulating gland, produces more stimulating hormone, which stimulates the first gland to produce more of its hormone. The rising level of hormone from the first gland in the bloodstream eventually reaches the level required in the body. Once that level is reached, the production of stimulating hormone by the second gland is turned down. This reduces the stimulation of the first gland, causing it to produce less hormone. When the level of hormone from the first gland drops below what the body needs again, the second gland (stimulating gland) turns its production of hormone back up, which turns the production of hormone from the first gland back up, and the process continues.

How does one cell population, the pluripotential stem cells, give rise to all the different blood cells?

A pluripotential stem cell has the potential to develop into any one of the blood cells. Which one is determined by the chemical or physiologic stimulus that acts on the stem cell. Each blood cell type has its own stimuli required to activate a pluripotential stem cell to start down the path of development of that specific blood cell.

What is a sacromere and what are its components?

A sacromere is the area from one Z line to the next Z line and is the basic contracting unit of skeletal muscle. Many sarcomeres lined up end-to-end form a myofibril. Each individual sarcomere is a myofibril only shortens slightly when the fiber is stimulated to contract, but when all the sacromere contractions are added together, the muscle fiber shortens considerably.

Describe the three types of resistance that prevent an animal from contracting a disease. Which type of resistance prevents humans from contracting canine distemper?

Acquired resistance Individual resistance Species resistance (prevents humans from contracting distemper)

What molecules in muscle act as the "batteries" to power the sliding of the actin and myosin filaments? What molecules function as the "battery chargers"?

Adenosine triphosphate (ATP) act as the batteries. Creatine phosphate (CP) act as the chargers.

How does the tapetum aid low-light vision?

After light has passed through the photoreceptors (rods and cones) in the retina, it reflects off the tapetum and passes back through the photoreceptors again, stimulating them a second time. Therefore, most animals can see better in dim light than we can.

Ecdysis in reptiles is under the control of what hormone?

Ecdysis is under the control of thyroid hormone.

How does the anatomy of a muscle or bone differ from its physiology? Which describes appearance and location and which describes function?

Anatomy deals with the form and structure of a muscle or bone. Physiology deals with their function.

What is the difference between anemia and polycythemia?

Anemia occurs when an animal's PCV is lower than the normal reference range and results in a decreased oxygen-carrying capacity of the blood. Polycythemia is when an animal's PCV is higher than normal. Polycythemia is an increase above normal in the number of red blood cells. There are three types of polycythemia: relative polycythemia, compensatory polycythemia, polycythemia rubra vera.

Why do you suppose mild to moderate pain often does not appear to affect the mood or behavior of domestic animals significantly?

Animals do not seem to have the same kind of emotional reaction to pain that humans do. They often seem to hide it well. Hiding signs of pain is a survival instinct for most animals. An animal that shows signs of pain is showing signs of weakness that might encourage other animals, including predators, to attack it.

What herpitiles are capable of gastric prolapse as a method of emptying their stomachs?

Anurans are capable of gastric prolapse.

What are two species of animal that require microbial fermentation to digest their food?

Any ruminant (cow, sheep, goat), horse, rabbit

From the aortic valve in the left ventricle to the right atrium, list, in order, the types of blood vessel a drop of blood will pass through.

Aorta, large to small elastic arteries, large to small muscular arteries, arterioles, capillaries, venules, small to large veins, vena cava, right atrium.

Where is aqueous humor produced? Where is it drained from the aqueous compartment of the eye?

Aqueous humor is produced in the posterior chamber by cells of the ciliary body. It is drained by the canal of Schlemm, and the fluid is returned to the bloodstream. The canal of Schlemm is a ringlike structure located at the edge of the anterior chamber at the angle where the iris and the cornea meet.

Which type of blood vessel carries blood away from the heart? Toward the heart?

Arteries carry blood away from the heart. Veins carry blood toward the heart.

How does an ATP molecule supply a cell with energy to do the work?

As a nutrient (e.g. glucose) is catabolized, the energy created is stored in ATP molecules. ATP stores this energy in the bonds between its phosphate groups. When these bonds are broken, that energy is released from the ATP molecule. To use the energy stored in ATP, enzymes must move the terminal phosphate group to another molecule. The receiving molecule is then called phosphorylated and temprarily has energy to do some work. During this process the ATP molecule loses a phosphate group and becomes ADP. Anotehr phosphate group can be used, resulting in teh creation of a molecule of AMP. As more glucose and other nutrients are metabolized, phosphate groups are joined to AMP, creating a renewed source of ATP.

Why does hair turn gray and then white as animals. age?

As animals age, melanin production decreases, and the hair begins to turn gray. White hair is formed when the cortex loses its pigment entirely and the medulla becomes completely filled with air.

How do homeostatic mechanisms influence the health of an animal?

As conditions inside and outside change, homeostatic mechanisms influence the health of an animal by helping to maintain a fairly constant internal environment inside the body, making life possible.

What is the mechanism by which glucose and amino acids are reabsorbed out of the proximal convoluted tubule and back into the body?

As the glomerular filtrate enters the lumen of the PCT, sodium is actively pumped out of the fluid and back into the bloodstream. Sodium in the tubular filtrate attaches to a carrier protein that carries it into the cytoplasm of the PCT epithelial cell. The transfer of sodium from the tubular lumen into the epithelial cell requires energy. At the same time glucose and amino acids attach to the same protein as sodium and follow the sodium into the epithelial cell by passive transport. Glucose and amino acids passively diffuse out of the tubular epithelial cell into the interstitial fluid and then into the peritubular capillaries.

What role does oxygen play in the electron transport system?

At the end of the electron transport chain, oxygen accepts the low-energy electrons, joins with hydrogen ions, and forms water (H2O). Thus, oxygen is the final acceptor of the electron.

How is an ion different from an atom?

Atoms are neutral. They contain the same number of protons as electrons. An ion is an electrically charged particle produced by either removing electrons from a neutral atom to yield a positive ion or adding electrons to a neutral atom to yield a negative ion.

Where are B cells produced? Where do they mature?

B cells originate in the red bone marrow. B cells mature in the red bone marrow.

Which cell produces antibodies?

B lymphocytes that have differentiated into plasma cells

What are some examples of these kinds of synovial joints: a. Ball-and-socket joints b. Gliding joints c. Hinge joints d. Pivot joints

Ball-and-socket joints: shoulder and hip joints Gliding joint: carpus and tarsus Hinge joint: elbow joint and atlantooccipital joint (between the skull and first cervical vertebra aka occipital bone and atlas) Pivot joint: atlantoaxial joint

Describe how sodium and potassium enter and exit the cell

Because of the concentration gradients of sodium (Na+) and potassium (K+), potassium tends to diffuse out of the cell and sodium diffuses in. To maintain appropriate levels of intracellular potassium and extracellular sodium, the cell must pump potassium into the cell and pump out sodium. Because diffusion is ongoing, the active transport system must work continuously. The rate of transport depends on the concentration of sodium ions in the cell. ATP is provided by cellular respiration and, with the assistance of the enzyme ATPase, is broken down for use as energy on the inner surface of the cell membrane. The pump can cycle several times using just one molecule of ATP, so that for every molecule of ATP, two potassium ions are moved intracellularly and three sodium ions are moved extracellularly.

What are caveolae and what roles do they play in the cell membrane?

Caveolae are minute invaginations of the cell membrane, like tiny dimples. Caveolae often pinch off entirely from the cell membrane, forming vesicles. These vesicles can form singly or in clusters (like tiny rosettes). Caveolae are formed only from rafts in the cell membrane that contain the protein caveolin.

What are the basic cellular functions that define life?

Cells can grow, develop, reproduce, adapt, become influenced by outside stimuli, maintain a stable internal environment, and convert food into usable energy. Each cell carries vital genetic material that governs its own development, metabolism, and specialization.

What is cellular metabolism? Can you think of routine cellular processes that represent specific examples of cell metabolism?

Cellular metabolism encompasses all the biochemical events involved in building molecules and breaking down nutrients, manufacturing, packaging, and excreting. Making proteins is one very important example of cellular metabolism.

What role does the centriole play in the formation of cilia and flagella?

Centrioles form the bases of cilia and flagella and in this role are known as basal bodies. Centrioles are structurally similar to cilia and flagella because all consist of microtubules. Centrioles are small, hollow cylinders composed of microtubules. Cilia and flagella are composed of nine pairs of microtubules that encircle a central pair of microtubules.

What part of the brain is critical for coordination, posture, and fine motor control? How does this part of the brain accomplish these responsibilities?

Cerebellum. The cerebellum compares the movement the body intends with the actual position of muscles and joints to determine if the intentions of the cerebral cortex are actually being carried out. If the movements are not being carried out accurately, the cerebellum will stimulate or inhibit muscles to fine-tune the movements.

The nasolacrimal duct system is absent in what order of reptiles?

Chelonians do not possess nasolacrimal ducts. The tears spill over the lid margin, so some degree of epiphora is normal in healthy animals.

Which reptiles have complete tracheal rings?

Chelonians possess complete cartilaginous tracheal rings.

Which reptiles have a tapetum?

Crocodilians have a tapetum

The part of the tooth that sticks above the gum line is the ____. It is covered with ____.

Crown. Enamel.

What is cytosol and what kind of molecules are found in it?

Cytosol is the protoplasm of the cell. It is a viscous, semitransparent liquid composed of dissolved electrolytes, amino acids, and simple sugars. Proteins are also suspended in the cytosol and give it its thick, jellylike consistency.

What are the principal components of cytoplasm?

Cytosol, cytoskeleton, organelles, inclusions

How might repeated exposure to loud sounds lead to progressive hearing loss?

Everything up to the generation of an auditory nerve impulse by the hair cells (sensory cells) in the organ of Corti of the cochlea involves movement: the tympanic membrane, the ossicles, the round and oval windows, the endolymph and perilymph in the cochlea, the tectorial membrane, and the microvilli of the hair cells. Loud noises cause exaggerated movements of all those structures. In the short term, irreparable damage rarely results. Over long periods of time, however, loud noises can cause damage to these mechanical structures that the body may not be able to fully repair. Some examples might include damage to the microvilli of the hair cells, thickening or displacement of the tectorial membrane, thickening of the membranes covering the round and oval windows, and damage to the delicate joints between the bony ossicles.

What is diffusion? Is it an active or a passive membrane process?

Diffusion is the passive movement of solute down a concentration gradient

Which digit is the dewclaw on the front leg of a dog?

Digit 1

How does an ectothermic animal maintain an appropriate body temperature? (reptiles and amphibians)

Ectothermic animals maintain their body temperatures in an appropriate range through a process called behavioral thermoregulation, which allows amphibians and reptiles to precisely regulate their body temperatures according to metabolic need. Movements within the thermal gradient of their habitat as well as postural changes enable herptiles to adjust their body temperatures as needed. For instance, many herptiles bask to elevate body temperatures and seek shade when they need to cool down. A snake trying to conserve body heat coils tightly to decrease surface area and consequently heat loss, whereas a hot snake uncoils to accomplish the opposite. Some animals can actually adjust the color and pattern of their skin to increase or decrease the absorption of thermal energy from the sun (for example, chameleons).

What is effusion? What is ascites?

Effusion is the escape of fluid from its normal vessels into a body cavity, where it may accumulate in large amounts. Ascites is the presence of an effusion in the peritoneal space of the abdominopelvis cavity and can be caused by a wide range of pathologic conditions (congestive heart failure, nephrosis, malignant neoplastic disease, and peritonitis)

The coronary artery is the first branch off the aorta. Is it a muscular or elastic artery? Why?

Elastic because it has to be able to withstand the high pressure of the blood leaving the left ventricle via the aorta.

What is an electrolyte?

Electrolytes are substances that have the ability to transmit an electrical charge.

How do electrolytes enter the cell?

Electrolytes enter cells via active transport (without the assistance of a concentration gradient).

List the endocrine and exocrine functions of the pancreas in birds.

Endocrine functions: Synthesizes hormones that regulate blood sugar and sugar metabolism in the liver (insulin, glucagon, and somatostatin). Exocrine functions: Produces pancreatic polypeptide that inhibits gastrointestinal motility and secretion and induces a sense of satiety.

What is the glycocalyx and what important role does it play in cellular interaction?

Glycocalyx is a sugar coating on the outside of the cell made of glycoprotein and glycolipid molecules. Similar to the stripes on zebras or the fingerprints on human hands, each glycocalyx is unique. It provides improtved cell-to-cell adhesion and represents an important biological marker for intercellular recognition and for the interactions between the cell and antibodies and the cell and viruses.

What part of carbohydrate metabolism occurs in the cytoplasm?

Glycolysis breaks down glucose to form pyruvate in the cytoplasm

How many biochemical steps are involved in glycolysis? Does glycolysis require oxygen?

Glycolysis involves 10 steps. It does not require oxygen.

What are the three kinds of processes found on vertebrae and what are their characteristics?

(1) The single dorsally projecting spinous process and (2) the two laterally projecting transverse processes vary in size among vertebrae and act as sites for muscle attachment and leverage to move the spine and trunk. (3) The articular processes are located on the cranial and caudal ends of the vertebral arches and help form the joints between adjacent vertebrae.

How do the basic actions and purposes of estrogens and progestins differ?

Estrogens are responsible for the physical and behavioral changes that prepare the female for breeding and pregnancy and signal the male that the time for breeding is approaching. Progesterone, the primary progestin, helps prepare the uterus to receive the fertilized ovum and is necessary for pregnancy to be maintained once the fertilized ovum implants in the uterus.

What are GAGs and what role do they place in connective tissue? Why do you suppose animals with joint injuries are sometimes given dietary supplements of GAGs?

Glycosaminoglycans (GAGs) are the ground substance in soft connective tissue. They are made of unbranched chains of glycoproteins. Animals with joint injuries are sometimes given GAGs because they may help with joint healing. Joints contain hyaluronic acid, which is the most commonly found GAG in connective tissue. GAGs are large molecules that help to orient the formation of fibers within the tissue during healing.

Why does mastitis in one quarter of a dairy cow's udder not necessarily spread to the other three quarters?

Each quarter is a completely separate unit from the other three, with its own milk-secreting systems and ducts leading down to their own teats. Infection does not directly spread from one quarter to another. It has to spread down through the teat and duct system of one quarter and up another, or, on rare occasions, it can spread systemically (through the bloodstream).

Describe a smooth muscle cell in terms of its size, shape, number of nuclei, and appearance under the microscope

- small and spindle shaped - non-striated - involuntary - one nucleus per cell

Describe a cardiac muscle cell in terms of size, shape, number of nuclei, and appearance under the microscope.

- striated but smaller than skeletal muscle cells - one nucleus per cell - longer than they are wide and have multiple branches - attach to each other by intercalated discs

What is the purpose of the sacculations?

- they prolong the time contents stay in the large intestines - they create extra volume - they allow for more time for absorption and microbial digestion

Describe a skeletal muscle cell in terms of cell size, shape, number of nuclei, and appearance under a microscope.

-large -long -multiple nuclei - striated or striped

Give three examples of energy-holding molecules.

1. ATP 2. NADH 3. FADH2

What are the three cycles of hair growth?

1. Anagen is the time of hair growth. 2. Telogen occurs when the maximum length of hair is achieved, the hair stops growing, the hair follicle shortens, and the hair is held in a resting phase. 3. Catagen is the period of transition between the anagen and telogen phases.

What factors influence the rate of chemical reactions?

1. Availability of the reactants, referred to as the concentration of reactants. The more reactants that are available, the more likely they will come in contact and be able to react with one another. 2. The temperature of the environment. When the temperature increases, the speed of molecular movement increases and the chance of molecules meeting improves. Temperature also increases the velocity at which the reactants meet, and the velocity provides the energy for the reaction. 3. Activation energy is the energy required for the reaction to happen. Some reactions have a higher activation energy and require an input of more energy for the reaction to occur. These reactions will occur at a slower pace. 4. Certain reactions require the presence of a catalyst. In living organisms, catalysts are usually special proteins that hold the reactants together so they may interact. The catalyst protein is not destroyed or used up by the reaction, and the reaction speed is increased when there are more catalyst proteins present. The special catalyst proteins are called enzymes.

What are the three main parts of a spermatozoan? What is the main purpose of each?

1. Head - Contains nucleus of the cell and is covered by a caplike structure called the acrosome. The acrosome contains digestive enzymes that are released once the spermatozoan is inside the female reproductive tract, helping the spermatozoan reach the ovum and penetrate through the layers surrounding it to accomplish fertilization. 2. Mid piece - power plant of the cell, containing a large concentration of energy-producing mitochondria arranged in a spiral pattern 3. Tail - long, thin tail resembles the flagellum that many single-celled organisms use for propulsion; it contains musclelike contractile fibrils that produce a whiplike movement of the tail and propel the cell forward once it is activated

What three factors play a role in the control of cell division?

1. Normal cells stop dividing when they come into contact with surrounding cells. This phenomenon is called contact inhibition. 2. Growth-inhibiting substances may be released from cells when their numbers reach a certain point. 3. A number of checkpoints are reached during cell division when the cell reassesses the division process. These checkpoints occur during the G1 and G2 phases of interphase.

What are the three types of muscle and what are some of the general characteristics of each type?

1. Skeletal muscle is controlled by the conscious mind and moves the bones of the skeleton. 2. Smooth muscle carries out most of the unconscious, internal movements in the body. 3. Cardiac muscle is found only in the heart and makes up the structure of the heart.

List, in order, the parts of the nephron. Indicate whether each specific part is found in the cortex or the medulla of the kidney.

1. renal corpuscle (cortex) 2. proximal convoluted tubule (cortex) 3. loop of Henle (medulla and cortex) 4. distal convoluted tubule (cortex)

Where is pseudostratified columnar epithelium found? (2 places)

1. respiratory tract 2. portion of the male reproductive tract

What is another name for each of these valves? 1. right AV valve 2. semilunar valve in the right ventricle 3. left AV valve 4. semilunar valve in the left ventricle

1. right AV valve = tricuspid valve 2. semilunar valve in the right ventricle = pulmonary valve 3. left AV valve = mitral or bicuspid valve 4. semilunar valve in the left ventricle = aortic valve

What are the three main parts of the penis?

1. roots 2. body 3. glans

List the four chambers that make up the ruminant stomach.

1. rumen 2. reticulum 3. omasum 4. abomasum

How can you tell that a molecule is an enzyme? List three characteristics of enzymes.

1. suffix is -ase 2. usually named for the substrate on which it acts (proteinases act on protein, lipase act on lipid, lactase acts on lactose) 3. name of hte enzyme may also indicate the kind of reaction that the enzyme initiates (synthetases are enzymes that synthesize or make new substances, transferases are enzymes that move one part of a molecule to another molecule)

What are the three categories of carbohydrate?

1. sugars 2. starches 3. cellulose

Where can simple cuboidal epithelium be found? (3 places)

1. surface of ovaries 2. secretory portions of glands (such as the thyroid) 3. lining of ducts of the liver, pancreas, kidney, salivary gland

Lipids are found in grasses and plants in the form of what three compounds?

1. triglycerides 2. glycolipids 3. free fatty acids

What are the four properties of water that make it so necessary for life?

1. universal solvent 2. ideal transport medium 3. high heat capacity and high heat of vaporization 4. lubrication

What are the six structures that make up the urinary system?

2 kidneys 2 ureters 1 urinary bladder 1 urethra

Why is a bilateral cryptorchid animal usually sterile?

A bilaterally cryptorchid (undescended testes) animal is usually sterile because spermatogenesis requires a temperature slightly lower than body temperature. The interior of the abdomen is too hot for spermatozoa to be produced. Testosterone continues to be produced, however. So a bilaterally cryptorchid animal has all the characteristics of a male animal but cannot reproduce.

Where are the bird's ears located?

A bird's ears are located on the sides of its head, behind and slightly below its eyes.

What is a blood feather?

A blood feather is a growing feather. Blood can be seen in the proximal part of the feather shaft during the entire growth phase. Injury to a blood feather not only results in bleeding but can prevent a feather from developing normally until molted again.

What is a Calorie?

A calorie is the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree Celsius.

What is a catalyst? Why are enzymes considered catalysts?

A catalyst is a substance that speeds up a reaction. Enzymes are catalysts because they speed up reactions by lowering the activation energy.

Of the thousands of different proteins that a cell could make, how many does it actually produce? Why?

A cell could make 100,000 proteins. It only makes a few hundred because cells each have different functions. The number produced depends on the function.

What is the difference between a cell, a tissue, an organ, and a system in an animal's body?

A cell is the basic functional unit of life. Specialized cells grouped together form tissues. Organs are formed by groups of tissues that work together for a common purpose. Systems are groups of organs involved in a common set of activities.

What is a hormone target?

A cell that has receptors for a particular hormone is referred to as a target of that hormone.

What is a chemical reaction?

A chemical reaction is a change or transformation in a substance during the formation or breaking of chemical bonds.

What is a chemical symbol?

A chemical symbol uses a letter or letters to refer to elements. Chemical symbols are derived from the element's name in English, Latin, or Greek.

What are the codons and what role do they play in transcription?

A codon is a set of three adjacent nucleotides in an mRNA molecule that specifies the incorporation of an amino acid into a peptide or polypeptide chain or that signals the end of peptide synthesis.

What are the main functions of platelets?

Hemostasis, the process by which blood is prevented from leaking out of damaged blood vessels. Platelets have specific roles in the clotting process along with endothelial cells in the blood vessel wall and coagulation factors. The two specific functions of platelets in hemostasis are the formation of a platelet plug and stabilization of that plug, making it irreversible.

What is the main difference between a heterophil and a neutrophil?

Heterophils differ from neutrophils in that they do not possess peroxidase and acid phosphatase, which are enzymes involved in breaking down necrotic material.

Name the skull bones that make up the internal bones of the cranium?

Internal bones of the cranium: sphenoid bone and rostral ethmoid bone

Name the skull bones that make up the internal bones of the face

Internal bones of the face: palatine bones, pterygoid bones, vomer bone, and turbinates

Describe the process of fertilization in salamanders.

Internal fertilization occurs in most salamanders. Male salamanders deposit packets of sperm called spermatophores onto substrate, which are subsequently picked up by the female salamander's cloaca. Female salamanders can store sperm for extended periods of time in pockets within the cloaca called spermatotheca.

What are the main muscles of expiration? How do they push air out of the lungs?

Internal intercostal muscles and abdominal muscles. The fibers of the internal intercostals run deep and at right angles to the external intercostal muscles. When they contract, they rotate the ribs backward, which decreases the size of the thorax and helps push air out of the lungs. When abdominal muscles contract, they push the abdominal organs against the caudal surface of the diaphragm. This pushes the diaphragm back into its full dome shape and also decreases the size of the thorax.

What are the two major periods that comprise the life cycle of the cell?

Interphase (when the cell is growing, maturing, and differentiating) and the mitotic phase (when the cell is actively dividing)

What is the importance of the esophageal groove?

It allows milk in a nursing ruminant to bypass the reticulorumen and go directly to the omasum. This prevents lactic acid buildup from fermentation in the reticulorumen.

Why is water called a polar molecule?

It has a slight positive charge in the area of the hydrogen atoms and a slight negative charge in the area of the oxygen atom. This polarity allows water molecules to form hydrogen bonds with each other and with other polar molecules.

Does ADH help promote or prevent the loss of large amounts of water in the urine?

It helps prevent the loss of large quantities of water in the urine. Inhibition of ADH would cause more water to flow out of the body in the urine.

How does a weak acid act as a buffer?

It helps the cell maintain a neutral pH by not allowing excessive hydrogen or hydroxyl ions to accumulate. In water, a weak acid will initially ionize into free hydrogen (H+) ions, a weak base product, and remaining intact weak acid molecules. The pH of the solution is not changed much because some of the chemical remains in acid form and some remains in the form of a weak base.

Why is the reproductive system of an individual animal only considered half a system?

It is considered only half a system because it requires a second animal (of the opposite sex) to fully carry out its functions.

Why is cartilage limited in thickness and slow to heal?

It is limited in thickness because nutrients diffuse from the surrounding perichondrium through the matrix to the chondrocytes. Therefore, chondrocytes that are farthest away from the perichondrium are potentially less well nourished than cells close to it. Cartilage is slow to heal because it is avascular.

What is the primary function of the respiratory system?

Its primary function is to bring oxygen (O2) into the body and carry carbon dioxide (CO2) out of it.

Why would keen hearing be important to the survival of a potential prey animal? Why would it be important to a predator?

Keen hearing allows a potential prey animal to hear movements caused by its predator and escape. Keen hearing allows a predator to hear the slightest movements made by its potential prey so that it can track and find it.

Why are patients with kidney failure often anemic?

Kidney failure patients are often anemic because of their deficiency of erythropoietin produced by the failing kidney, which normally stimulates red bone marrow to increase production of oxygen-carrying red blood cells.

What is a molecule?

Molecules are atoms joined together by chemical bonds.

How are the functions of neurons and neuroglia different from each other?

Neurons are the basic functional unit of the nervous system. They are the smallest pieces of teh system that show basic nervous system functions, such as responding to stimuli and conducting impulses from one part of the cell to another. The neuroglia or glial cells (greek meaning "glue"), structurally and functionally support and protect the neurons. They outnumber neurons 10 to 1, but they are not directly involved in the transmission of info or impulses through the nervous system. They are important parts of infrastructure necessary for the neurons to do their jobs.

What three parts compose a nucleotide?

Nucleotides are composed of a nitrogenous base, a 5-carbon (pentose) sugar, and a phosphate group.

How does a nucleotide differ from an amino acid?

Nucleotides are the building blocks of nucleic acids such as DNA, but amino acids are the building blocks of proteins.

What is a nucleotide and how is it structured?

Nucleotides are the building blocks or units of DNA and RNA molecules and are composed of three subunits: a nitrogenous base, a five-carbon sugar, and a phosphate group. DNA and RNA nucleotides are linked to form a "backbone" of alternating sugar and phosphate groups. The nitrogenous bases project out of this backbone.

What is oxidative phosphorylation?

Oxidative phosphorylation is the process in which ATP is produced as electrons are transferred from NADH or FADH2 to O2 by a series of electron carriers in the electron transport chain. This is the major source of ATP in aerobic organisms.

How does the basement membrane act as a partial barrier between the epithelial cell and the underlying connective tissue?

Oxygen and nutrient molecules are supplied to the epithelial cells by diffusing through the basement membrane from capillaries in the underlying connective tissue. Similarly, nutrient substances that are absorbed and waste that is excreted by the epithelium diffuse across the basement membrane into the blood supply of the connective tissue.

What is the general effect of sympathetic nervous system stimulation on visceral smooth muscle? What is the effect of parasympathetic nervous system stimulation?

Parasympathetic nerve stimulation increases smooth muscle activity

What two hormones play important roles in maintaining homeostasis of blood calcium levels in the body? Which one prevents hypercalcemia? Which prevents hypocalcemia?

Parathyroid hormone (PTH), also called parathormone, and calcitonin. PTH helps prevent hypocalcemia, and calcitonin helps prevent hypercalcemia.

What are the three primary salivary glands in a dog?

Parotid, sublingual, mandibular (zygomatic)

What is the name of a bond holding two amino acids together?

Peptide bond

Which chemical hormone group(s) bind to receptors on the target cell membrane? In the cytoplasm or nucleus?

Peptide hormones and monoamine catecholamine hormones bind to receptors on the target cell membrane. Steroid hormones and monoamine thyroid hormones bind to receptors in the cytoplasm or nucleus.

What are the three main chemical groups of hormones?

Peptide hormones, steroid hormones, and monamine hormones

What is the name of the pattern of muscular contractions and dilations that moves food forward through the esophagus and other parts of the digestive system?

Peristalsis

What do peroxisomes do in the cell?

Peroxisomes are commonly found in liver and kidney cells and are important in the detoxification of various molecules. Peroxisomes contain enzymes that use oxygen to detoxify a number of harmful substances, including alcohol and formaldehyde. They also assist in the removal of free radicals, which are normal products of cellular metabolism that can be harmful to the cell in large quantities because they interfere with the structures of proteins, lipids, and nucleic acids.

Describe the three types of endocytosis

Phagocytosis, pinocytosis, receptor-mediated endocytosis

Name the bones of the pelvic limb from distal to proximal

Phalanges, metatarsal bones, tarsal bones, fibula, tibia, patella, fabellae, femur, pelvis

How do glands develop embryologically?

Multicellular glands form during embryonic development from the infolding of a layer of epithelial cells. Initially, these "invaginations" form ducts and tubules that maintain contact with the surface epithelium. In the course of development, some of the glands lose the ducts and become separated from the parent epithelial sheet. In this way, glands are derived from epithelium.

In what ways are muscle fibers uniquely adapted for contraction?

Muscle fibers are composed of specialized proteins called actin and myosin, which are arranged into microfilaments. Contraction, or shortening, of the muscle cell occurs when the microfilaments slide over one another like the bars in an old-fashioned slide rule. In this way, the cells change shape and can be made shorter or longer.

What is a muscle?

Muscle is one of the four basic types in the body that assist in movements.

What is myoglobin and why is it important?

Myoglobin is a large protein in muscle that can store oxygen for times, like during strenuous exercise, when more oxygen is needed by the muscle.

Which contractile protein filaments make up the dark bands of skeletal muscle cells? Which makes up the light bands?

Myosin myofilaments make up the dark bands. Actin filaments make up the light bands.

Describe the three stages of differentiation of lymphocytes.

Native cells that have entered the lymphatic system but have not encountered an antigen. Cytotoxic or effector cells have been activated and are involved in eliminating a pathogen. Memory cells are the survivors of past infections, capable of providing long-term immunity.

What cell types of innate defense targets tumor cells?

Natural killer cells

Describe the effect of nerve stimulation on the functioning of visceral smooth muscle vs. multi-unit smooth muscle.

Nerve stimulation does not initiate smooth muscle action; it modifies it.

What is the difference in the estrous cycle intervals of polyestrous, seasonally polyestrous, diestrous, and monoestrous animals?

Polyestrous animals, such as cattle and swine, cycle continuously throughout the year if they are not pregnant. As soon as one cycle ends, another begins. Some polyestrous animals show seasonal variations in their estrous cycles. They cycle continuously at certain times of the year and not at all at others. These animals are called seasonally polyestrous animals. Diestrous animals have two cycles per year, usually in the spring and fall. Monoestrous animals usually have only one cycle each year.

What is another name for a complex, multiunit carbohydrate?

Polysaccharide

Which electrolytes are normally more concentrated outside the cell and which ones are more concentrated inside the cell?

Potassium is more concentrated inside the cell, and sodium is more concentrated outside the cell.

What happens during prehension? During deglutination? During mastication?

Prehension = bringing food to the mouth Deglutination = swallowing Mastication = chewing

Which particles are in the nucleus of an atom?

Protons and neutrons

What is the electrical charge of each particle?

Protons have a positive electrical charge, neutrons have no electrical charge, and electrons have a negative electrical charge.

Give two examples of conditions that result from fluid shifts

Pulmonary edema and cutaneous edema are both examples of abnormal shifts in fluid between compartments

Which main pulmonary blood vessel contains bright red, high-oxygen blood: the pulmonary artery or the pulmonary vein? Why?

Pulmonary vein

What are the molecular components of rafts and what role do rafts play in the life of a cell?

Rafts are composed of densely packed phospholipids, cholesterol, and protein. These dense regions are stiff and form rigid, raftlike structures within the otherwise fluid phospholipid bilayer of the cell membrane.

What are the components of areolar tissue?

Randomly placed fibers and cells suspended in a thick, translucent ground substance. The tissue appears relaxed, with a myriad of round and star-shaped cells placed among crisscrossing fibers. The predominant cell is the fibroblast, a large spindle-shaped cell that manufactures the elastic, reticular, and collagenous fibers found throughout the tissue.

What are the three main categories of blood cell?

Red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes)

What is the difference between red bone marrow and yellow bone marrow?

Red bone marrow is bone marrow that is actively making blood cells. Its location in the animal's body changes as the animal matures. Yellow bone marrow is inactive or fatty bone marrow that is no longer producing blood cells.

How does relaxin help prepare a pregnant animal for parturition?

Relaxin causes ligaments between the bones surrounding the birth canal to soften and relax, facilitating the passage of the newborn during parturition.

How does the reptile iris differ from that of mammals? Why is this clinically important?

Reptiles are similar to birds in that the iris is made up of skeletal muscle and is under voluntary control. In mammals, the iris is under involuntary control. Therefore, mydriatic agents used to dilate the pupil for ophthalmic examinations in mammals are not effective in reptiles. A direct pupillary light response is usually noted, but consensual reflexes are often not seen.

Why are reptiles unable to sustain physical activity for long periods of time?

Reptilian muscles are incapable of sustained aerobic metabolism and switch quickly to anaerobic metabolism with prolonged physical exertion. Anaerobic metabolism is less efficient than aerobic metabolism and results in rapid buildup of lactate. Lactate decreases the pH of the blood and tissues and is metabolized slowly by reptiles. For this reason, reptiles are unable to sustain physical activity and are capable of only short bursts.

What is the significance of the thymus?

Responsible for maturation of T lymphocytes, which are responsible for cell-mediated immunity.

Which layers of the eyeball contain photoreceptors?

Retina (the inner nervous layer)

What is meant by the term retroperitoneal?

Retroperitoneal means outside of the abdominal cavity, between the parietal peritoneum and the dorsal abdominal muscles.

What is happening in the other three heart chambers during left atrial diastole?

Right atrial diastole, right and left ventricular systole

Right-to-left cardiac shunting serves what function in reptiles?

Right-to-left cardiac shunting allows reptiles to survive in times of oxygen deprivation (diving in some reptiles or consumption of large prey in snakes). Right-to-left cardiac shunting is facilitated by an increase in pulmonary vascular resistance. Resumption of breathing results in a decrease in pressures within the pulmonary vasculature and restoration of pulmonary blood flow.

What kind of vision do the rods in the retina perceive? What do cones perceive?

Rods are more sensitive to light than cones, but they produce a somewhat coarse image in shades of gray. The cones are more sensitive to color and detail than are the rods, but they do not function well in dim light. So rods are the main receptors for dim light vision, and cones perceive color and detail.

Which of the four chambers is the largest fermentation chamber and on which side of the animal would you look at to see whether it was bloated?

Rumen. Left.

How would the rupture or perforation of an eardrum affect hearing?

Rupture or perforation of an eardrum would decrease the tension of the structure. This would decrease the force of the vibrations that move along the ossicles to the inner ear, impairing hearing.

What is the pacemaker of the heart and where is it located?

SA node, wall of the right atrium

What are the two main functions of the testis? Where in the organ does each take place?

Spermatogenesis take place in seminiferous tubules, and hormone production occurs in interstitial cells between the seminiferous tubules.

What is the general effect of sympathetic nervous system stimulation on cardiac muscle? What is the effect of parasympathetic nervous system stimulation?

Sympathetic nerves cause the heart to beat harder and faster. Parasympathetic nerves cause the heart to beat slower and with less force.

With which branch of the autonomic nervous systems are the alpha1, beta1, and beta2 receptors associated? What happens to the body when these particular receptors are stimulated?

Sympathetic nervous system. Alpha1-adrenergic receptors typically are found on blood vessels and cause the vasoconstriction of the skin, GI tract, and kidney associated with sympathetic stimulation. The increase in heart rate and force of contraction are the result of stimulation of beta1-adrenergic receptors by catecholamines, and the bronchodilation associated with sympathetic stimulation results from beta2-adrenergic receptor stimulation.

What is synovial fluid and why is it important to the functioning of a synovial joint?

Synovial fluid is produced by the lining of the joint capsule. It lubricates synovial joints, is transparent, and has the viscosity of a medium-weight motor oil. It can be aspirated and analyzed to help diagnose some disorders.

Where are synovial membranes found? How are they different from other membrane types?

Synovial membranes line the cavities of joints. They are different from other membrane types because they have no epithelium and are composed completely of connective tissue.

What are the three types of chemical reactions?

Synthesis reaction (a new, more complex chemical is made from multiple simpler chemicals). Decomposition reaction (a complex substance breaks down into its simpler pats). Exchange (certain atoms are exchanged between molecules. It is a combination of a synthesis and a decomposition reaction).

The working phase of a cardiac cycle is ______. It involves _____ that generates an impulse that results in muscle contraction.

Systole, depolarization

Where are T cells produced? Where do they mature?

T cells are produced in the red bone marrow and mature in the thymus.

What are the types of lymphocyte?

T cells, B cells, and natural killer cells

What is tail autonomy?

Tail autonomy is a defense mechanism of many lizard and salamander species. Tail autonomy allows lizards to drop their tails when being pursued or attacked by a predator. The discarded tail usually continues to wiggle about, which is intended to draw the attention of the attacker while the lizard makes its escape. The tails of lizards capable of autonomy have fracture planes along which they break. When tails are lost via autonomy, there is usually little to no blood loss because the muscles of the tail strongly contract and the blood vessels are occluded. The lost tail can regenerate with a stiff cartilaginous rod replacing the spine. The regenerated tail is usually smaller and stiffer than the original in lizards. Usually the regenerated tail of a salamander very closely resembles the original.

What is the difference between a tendon and a ligament?

Tendons join muscles to bones. Ligaments join bones to other bones.

What nitrogenous waste products are produced most frequently by aquatic amphibians? What nitrogenous waste products are produced by terrestrial amphibians?

Terrestrial amphibians produce uric acid, and aquatic or semiaquatic reptiles produce ammonia and/or urea.

Which hormone are anabolic steroid drugs related to?

Testosterone

What is a CBC?

The CBC is also known as the hemogram or complete blood count. It is used to evaluate the components of a blood sample: plasma or serum, red blood cells, white blood cells, and platelets.

What are the anatomical differences between the Central Nervous System (CNS) and Peripheral Nervous System (PNS)?

The CNS is composed of the brain and spinal cord, which are found associated within the central axis of the animal's body. Peripheral means "to the side" or "away from the center" therefore, the PNS is made up of those components of the nervous system that extend away from the central axis outward toward the periphery of the body.

Describe the components of an avian ECG.

The ECG consists of P, QRS, and T waves that correspond to specific muscular activities. The P wave corresponds to contraction and relaxation of the atria. The QRS wave complex represents contraction of the ventricles. The T wave corresponds to relaxation of the ventricles.

What is the difference betweeen an ECG and an ECHO?

The ECG detects the electrical activity in the heart and is used to evaluate the cardiac conduction system; the ECHO uses ultrasound waves bounced off the heart to evaluate size, shape, and movement of the heart. Doppler ECHO evaluates blood flow in the heart.

What does the Golgi apparatus do in the cell?

The Golgi apparatus acts as a modification, packaging, and distribution center for molecules destined for either secretion or intracellular use. It also functions in polysaccharide synthesis and in the coupling of polysaccharides to proteins (glycoproteins) on the cell surface.

When a piece of lung from a dead newborn animal is dropped into water, it sinks. What conclusion can be drawn about whether the newborn animal was born dead and never breathed or took some breaths before dying?

The animal was born dead. If it had been born alive and had breathed, the lung piece would have floated.

Why do inclusions vary in appearance? What functions do they perform?

The appearance of inclusions varies depending on what they contain and whether or not they have an envelope. They store substances the cell eventually uses.

List the five sections of the avian oviduct and their functions.

The avian oviduct can be divided into the following five sections: 1. Infundibulum: possesses folds that grab an ovum as it comes out of the ovary 2. Magnum: secretes layers of albumin (egg white) around the egg 3. Isthmus: deposits the keratin shell membrane 4. Uterus: deposits watery albumin, a hard external shell, and pigmentation; large and muscular, it is also called the shell gland; an egg spends the most time here 5. Vagina: secretes mucus to assist in egg laying; stores sperm for several hours to several days

Describe the basic anatomy of a bird's beak and claw. When trimming these structures, what should you be careful to avoid?

The beak consists of an upper and lower mandible. It is covered with a tough, horny keratin layer that grows continuously. Beaks vary in their hardness and flexibility, depending on their function. The claw possesses a horny sheath derived from specialized scales at the end of each toe. Like the beak, it also grows continuously. Species differ in the types of claws they possess, based on their perching habits and method of procuring food. For example, chickens, pheasants, and other ground feeders have short, sharp claws that are used to scratch the ground for food; birds of prey have claws called talons that are long, sharp, and rounded to catch and kill their prey; vultures, which are scavengers, have short, blunt claws; and climbing birds, such as woodpeckers and nuthatches, have strongly curved claws for gripping. When coping beaks and claws, one must be careful to avoid the blood and nerve supply.

What changes does an ovarian follicle undergo as it develops from a primordial follicle to a mature follicle?

The beginning stage of follicle development in the ovary is the primordial (sometimes called the primary) follicle. After FSH is released from the anterior pituitary, the follicle undergoes follicular recruitment or follicular activation and is now called a growing follicle. The follicular cells become thickened into cuboidal shapes and begin to multiply. Multiple layers of follicular cells form around the developing oocyte. At this stage the follicular cells are called granulosa cells. As the granulosa cells multiply, the follicle starts to grow rapidly in size. The granulosa cells do more than just physically surround the developing oocyte. They also produce estrogen hormones that begin preparing the animal for breeding and pregnancy. The larger the follicle or follicles become, the greater the amount of estrogens produced. As the follicle continues to grow, fluid-filled spaces begin to form between the granulosa cells. The spaces gradually become confluent (join together), forming one large fluid-filled space called the antrum. When the follicle has reached its maximum size, it looks like a large blisterlike structure on the surface of the ovary. At this stage it is called a mature follicle. Alternative names for the mature follicle include graafian follicle and vesicular ovarian follicle. At this stage, estrogen production from the follicle or follicles is at maximum level, and the animal is ready for breeding to take place.

Which vein can be used in most common animal species for venipuncture? Where is it located?

The bilateral jugular veins located in jugular grooves on the ventral aspect of the neck from the mandible to the shoulder.

What helps keep dangerous and certain drugs from leaving the blood and entering the brain? Describe this structure.

The blood-brain barrier consists of capillary-wall cells in the brain that are aligned tightly together without openings, or fenestrations. In addition, the capillaries in the brain are covered by the cell membranes of glial cells.

List the bones in the avian leg beginning at the hip and extending down to the toes.

The bones in the avian leg are: femur, patella, tibiotarsus, fibula, tarsometatarsus, and the phalanges of digits one through four. The number of digits varies from two to four, depending on the type of bird.

List the bones in the avian wing from the shoulder to the wing tip.

The bones of the avian wing are: humerus, radius, ulna, ulnar carpal, radial carpal, carpometacarpus, alula (first finger), and the phalanges of the second and third fingers. The three fingers are digits two, three, and four. The shoulder girdle consists of the coracoids, scapula, and clavicle.

What are the brachium and the antebrachium, and which bones form them?

The brachium is the upper forelimb between the elbow and shoulder joints formed by the humerus. The antebrachium is the forelib formed by the radius and ulna

What is the function of the brush border on the epithelial cells of the proximal convoluted tubule?

The brush border increases the cellular surface area exposed to the fluid in the tubule by a factor of about 20. This is especially important to the PCT's reabsorption and secretion functions.

What is the buffy coat?

The buffy coat is the layer of white blood cells and platelets that settles on top of the red blood cell column in a packed cell volume tube after centrifugation. It appears cream or buff colored. The thickness of the buffy coat can be used as an indicator of the total number of leukocytes and platelets in the sample.

What types of protein are found in the cell membrane?

The cell membrane contains structural and globular proteins. Globular proteins include integral and peripheral proteins.

What is the centrosome and what important roles does it play in the life of the cell?

The centrosome is a critical region in the cytoplasm adjacent to the nucleus. It is the site where microtubules are constructed and demolished. The centrosome includes centrioles, pericentriolar material, and asters. Microtubules are the thickest and strongest fibers in the cell and form the "zip-line"-like cables in the cytoskeleton that transport organelles and other intracellular structures from one place to another inside the cell. They also help form the spindle fibers during cell division and are a central part of cilia and flagella.

What are the four orders of living reptiles? What are the three orders of amphibians?

The class Reptilia comprises four orders: (1) Crocodylia (alligators and crocodiles), (2) Squamata (snakes and lizards), (3) Chelonian (turtles and tortoises), and (4) Rhynchocephalia (tuataras). The class Amphibia is made up of three orders: (1) Gymnophiona (caecilians), (2) Anura (frogs and toads), and (3) Caudata (salamanders and newts).

The cornea and sclera are both made up substantially of collagen fibers. Why is the cornea transparent, but the sclera opaque?

The cornea contains no blood vessels, and the amount of water it contains is carefully controlled.

What is the main refractive structure of the eye? Why?

The cornea is the main refractive structure because of its curvature and the extreme difference between its optical density and that of the air in front of it.

What is the cytoskeleton and what is its function?

The cytoskeleton is a three-dimensional frame for the cells that is neither rigid nor permanent. It is a flexible, fibrous structure that changes in accordance with the activities of the cell. The cytoskeleton gives support and shape to the cell and enables it to move, provides direction for metabolic activity, and anchors the organelles.

What is the difference between the endocardium and the pericardium?

The endocardium is the membrane that lines the chambers of the heart. It lies on the internal surface of the myocardium; the epicardium lies on the external surface of the myocardium and is synonymous with the visceral layer of the serous pericardium.

What is the energy of activation in a biochemical reaction?

The energy of activation is the energy needed to initiate a biochemical reaction.

On which side of the neck is the esophagus located in birds? Does this differ from mammals?

The esophagus is on the right side of the neck in birds. In mammals it is on the left and then returns to the midline.

How do the stages of the estrous cycle relate to the physical events of the ovarian cycle?

The estrous cycle stages are proestrus, estrus, metestrus, and diestrus. Anestrus occurs in some animals between breeding seasons. Proestrus is the period of follicular development in the ovary. During this stage, follicles begin developing and growing. As they increase in size, the follicles' output of estrogen increases accordingly, causing many physical changes that prepare the rest of the reproductive tract for ovulation and breeding. These changes include thickening and development of the linings of the oviduct, uterus, and vagina. The epithelial lining of the vagina also begins cornifying, that is, forming a layer of tough keratin on its surface to help protect against the physical trauma of breeding that is about to come. Estrus is the heat period, or the period of sexual receptivity in the female. It occurs when the estrogen level from the mature follicles reaches its peak. This high estrogen level causes physical and behavioral changes that signal the female's willingness to breed to the male. Metestrus is the period after ovulation when the corpus luteum develops. The granulosa cells left in the now-empty follicle begin to multiply under continued stimulation from LH. They soon produce a solid structure, the corpus luteum (yellow body), which is about the same size as the former mature follicle. The hormone progesterone produced by the corpus luteum temporarily inhibits follicular development in the ovary, causes the lining of the uterus to get very thick in preparation for implantation of a fertilized ovum, and causes loss of the cornified epithelial lining that developed in the vagina during proestrus and estrus. Diestrus is the active luteal stage when the corpus luteum has reached maximum size and exerts its maximum effect. If the animal is bred and becomes pregnant, the corpus luteum receives an endocrine signal from the developing embryo and is retained well into the pregnancy. If the animal is not pregnant, the corpus luteum degenerates at the end of diestrus. The animal either goes back into proestrus or the ovary shuts down and the animal goes into anestrus. Anestrus is a period of temporary ovarian inactivity seen in seasonally polyestrous, diestrous, and monoestrous animals. It is the period between breeding cycles when the ovary essentially shuts down temporarily.

Name the two types of sensory nerve ending in the skin and describe where they are located in birds.

The first type of nerve ending is called a Grandry's corpuscle, and groups of these are located in the tongue and palate of many species that dig for food, such as woodcocks and sandpipers. The second type of nerve ending is called a Herbst corpuscle. These are also often located in areas of the mouth such as the tongues of woodpeckers, the palates and beaks of ducks, and the mouth folds of young birds. In addition, Herbst corpuscles are located in the cloaca, legs, wings, uropygial gland, and bases of many feathers, including the primary flight feathers. These corpuscles are very responsive to even the slightest feather movement. This characteristic explains why birds are sensitive when just the tips of their feathers are touched.

What type of feathers are the flight and tail feathers? Describe their microstructure.

The flight and tail feathers are contour feathers (also called remiges on the wings, auriculars around the ear openings, and rectrices on the tail). Contour feathers are moved by muscles attached to the walls of the follicles. The microstructure consists of several structures. The inferior umbilicus is a tiny opening at the base of the feather, where it inserts into the skin. When a new feather is developing, it receives nourishment from blood vessels that pass through this opening. The superior umbilicus is a tiny opening on the feather shaft where the webbed part of the feather begins. In some birds it gives rise to an afterfeather, which is an accessory feather that is thought to provide additional insulation to retain a bird's body heat. The calamus (quill) is the round, hollow, semitransparent portion of a feather that extends from the inferior umbilicus to the superior umbilicus. The rachis is the main feather shaft. The vane is the flattened part of a feather that appears weblike on each side of the rachis. The vane consists of numerous slender, closely spaced barbs. The barbs give rise to barbules, which have rolled edges and tiny hooklets (hamuli). These hooklets interlock each barb with an adjacent one, forming a tightly linked, flexible web. The degree of tightness varies with the species. For example, the contour feathers of owls have fewer barbules than do those of hawks. The result is a looser feather weave that feels softer and allows air to pass through, creating silent flight.

What are the correct names for the bumps and fissures that make the cerebral cortex appear wrinkled?

The folds, called gyri (plural of gyrus), are separated by deep grooves called fissures and more shallow grooves called sulci (plural of sulcus). The most prominent groove is the longitudinal fissure, which divides the cerebrum into right and left cerebral hemispheres.

Describe the four classifications of newly hatched eggs.

The four different classifications of newly hatched chicks are: 1. Altricial: Some chicks are hatched with their eyes closed and their skin bare. They require a great deal of care before they can leave the nest. Parrots and songbirds fall into this category. 2. Semialtricial: At hatching, these chicks are covered with down, are immobile, and may have their eyes open (herons and hawks) or closed (owls). 3. Precocial: These chicks are covered with downy feathers, have their eyes open, and are quite mobile, leaving the nest quickly. Ducks and geese are good examples. 4. Semiprecocial: Some species, such as gulls and terns, are born with a downy covering and open eyes but move only a short distance from the nest and are fed by their parents.

What is the common function of all white blood cells?

The function of all white blood cells is to provide defense for the body against foreign invaders.

Define the function of the uropygial gland. Do all birds possess this gland?

The function of the uropygial (preen) gland is the secretion of an oily, fatty substance that helps to clean and waterproof the feathers. The gland is completely lacking in some parrots, ostriches, and a few other species.

How might abnormalities in an animal's anatomy or physiology have a negative impact on its health and wellbeing?

The functions of the parts of an animal's body are extremely interrelated. Therefore, an abnormality with the anatomy or physiology of one part can effect other parts.

What is the difference between tubular reabsorption and tubular secretion?

The glomerular filtrate contains substances found in plasma that the body doesn't want to lose because it needs them to maintain homeostasis. Tubular reabsorption involves removing these substances from the tubular filtrate. The useful substances are reabsorbed from the tubules into the peritubular capillaries. Many waste products and foreign substances are not filtered from the blood in sufficient amounts from the glomerular capillaries. The body still needs to get rid of these substances, so it transfers them from the peritubular capillaries into the tubular filtrate in the tubules to be eliminated in urine.

Where are goblet cells found? What type of secretion do they produce?

The goblet cell is a modified columnar epithelial cell found interspersed among the columnar cells of the respiratory and digestive tracts and in the conjunctiva of the eye. Goblet cells secrete mucin, a thick, sticky mixture of glycoproteins and proteoglycans. When combined with water, mucin becomes mucus. The mucus functions in two ways: it helps protect the apical surface of the epithelial layer, and it assists with the entrapment of microorganisms and foreign particles.

How does the normal anatomy and physiology of cells in an animal's body impact the health of the animal as a whole? How does the normal anatomy and physiology of the animal's body as a whole impact the health of each of its cells?

The health of cells affects the health of tissues, which affects the health of organs, which affects the health of systems, which affects the health of the whole body. Similarly, the health of the body affects the health of the systems, which affects the health of the organs, which affects the health of tissues, which affects the health of cells.

What is the difference between a heart rate and a pulse?

The heart rate measures the number of ventricular contractions in 1 minute; the pulse measures the rate of alternating stretching and recoiling of an elastic artery wall as blood passes through it over 1 minute.

If the cardiac output and stroke volume both decrease, what has to happen to the heart rate to achieve equilibrium?

The heart rate will have to increase.

Where does bilirubin come from? How is it eliminated from the body?

The heme pigment from hemoglobin is disassembled and eliminated from the body. To do this it is first converted to bilirubin, which is then carried to the liver by the plasma protein, albumin. Bilirubin has to attach itself to albumin because at this stage it is not water soluble. At this point the bilirubin is classified as unconjugated or "free" bilirubin. In the liver bilirubin is joined or conjugated to a compound called glucuronic acid. The combined bilirubin and glucuronic acid molecule is water soluble and excreted as a bile pigment into the intestines. The bilirubin is now classified as "conjugated" bilirubin. In the intestines, conjugated bilirubin is converted into urobilinogen by bacteria. Some of this urobilinogen will be reabsorbed and eliminated in the urine as urobilin. Some will be converted to another compound, stercobilinogen, and excreted in the stool as stercobilin.

What is the hilus of the lung and why is it important?

The hilus is a small, well-defined area on the medial side of each lung where air, blood, lymph, and nerves enter and leave the lung. It is the only area of the lung that is "fastened in place." The rest of the lung is free within the thorax.

What is the difference between the hilus of the kidney and the renal pelvis?

The hilus is the area on the medial side of each kidney where blood and lymph vessels, nerves, and the ureter enter and leave the kidney. The renal pelvis is inside the hilus and is a urine collection chamber at the beginning of the ureter.

What two types of hormone are produced in the ovary? Where is each produced?

The hormones produced in the ovaries are estrogens and progestins. Estrogens are produced by the cells of the developing ovarian follicles. Progestins, principally progesterone, are produced by the corpus luteum, which develops from the empty follicle after ovulation.

Why are the hyaline cartilage rings important to the function of the trachea?

The hyaline cartilage rings prevent the trachea from collapsing each time the animal inhales.

Describe the lipid bilayer. Which part is hydrophobic and which part is hydrophilic?

The hydrophilic heads of the phospholipid bilayer are attracted to the aqueous environments found in the extracellular and intracellular spaces. The lipid tails, on the other hand, are hydrophobic and are repelled by these aqueous compartments. Therefore, they are turned inward and face one another inside the bilayer.

How does the membrane structure of the mitochondrion assist in the process of cellular respiration?

The inner membrane of the mitochondrion houses a series of cytochrome molecules, which make up the electron transport system. As electrons are passed from one cytochrome molecule to another, energy is released and used to transport protons from the mitochondrial matrix across the inner membrane to the intermembrane space. Because protons are positive, this establishes a positive charge on the outside of the inner membrane relative to the matrix side. The electrical gradient that is established is a form of stored (potential) energy. Energy is released when protons rush back into the mitochondrial matrix.

What is the function of the iris?

The iris controls the amount of light that enters the posterior part of the eyeball. The pupil enlarges in low light conditions and gets smaller in bright light.

What is the anatomical names for the cannon bone and the splint bones in a horse?

The large metacarpal (cannon) bone of the horse is assumed to be what is left of metacarpal III, and the smaller splint bones on either side of it are designated as metacarpals II and IV.

If your left hand is on a goat's belly and your right hand is on its back, which hand is on the animal's dorsal surface and which is on its ventral surface?

The left hand is on the ventral surface, and the right hand is on the dorsal surface.

Why can a bird perch while sleeping?

The leg muscles are close to the center of gravity. In perching species, tendons that control the movement of the toes originate from flexor muscles in the thigh and extend over the heel joint into the digits. Extensor tendons run down the front of the tibiotarsus and metatarsus, whereas the flexor tendons run along the back. The flexor tendons sit in a grove at the top of the metatarsus. When a bird bends its legs to perch, the tendons also bend and pull the toes closed around the perch. This is called the perching reflex and allows a bird to firmly grip its perch while sleeping.

What does the lysosome do in the cell?

The lysosome's principal responsibilities are the breakdown of nutrient molecules into usable smaller units and the digestion of intracellular debris. Lysosomes may also release their enzymes outside the cell to assist with the breakdown of extracellular material. In addition, lysosomal digestion is responsible for decreasing the size of body tissues (for example, shrinkage of the uterus after parturition and atrophy of muscles in paralyzed animals).

What are some specific examples of cofactors?

The magnesium ion is a cofactor in reactions that involve the transfer of a phosphate group and is therefore found in virtually all cells. Elements such as iron, zinc, or copper, for instance, are needed to complete the shape of a binding site and are called cofactors.

What is the major component in the nitrogenous waste of birds? What are the advantages to producing this type of waste?

The major component in bird waste is uric acid, not urea, as in mammals. This finding is significant for several reasons. First, uric acid is more efficient in eliminating nitrogen; each molecule removes twice as much nitrogen as urea. Second, uric acid conserves water because it is relatively insoluble and can be eliminated with only a small volume of water. It takes 60 ml of water to excrete 1 g of urea, whereas it only takes 1.5 to 3 ml of water to excrete the same amount of uric acid. Finally, the production of uric acid is critical to the survival of embryos within the egg. The only waste products that can be eliminated through an eggshell are gases. Other waste products must be stored in the egg throughout the embryo's development. Because urea requires a relatively large volume of water for excretion, the egg would not have enough room to house it. Also, high quantities of urea are toxic and would kill the embryo. The relatively small amount of nontoxic uric acid produced can be stored in the egg with no ill effects.

How do the wing and tail feathers differ between predatory and prey bird species?

The major flight feathers of many prey species are loosely seated in the follicles so that they can drop feathers quickly if grabbed as an aid to escape a predator. In predatory bird species, such as birds of prey, the feathers are seated very strongly in the follicles, and pulling out a flight or tail feather can result in permanent follicle damage, preventing a new feather from ever growing in.

What is keratinization and why is it an important process?

The majority of cells in the epidermis are keratinocytes. Keratinocytes located along the basement membrane are well nourished by the blood supply of the underlying dermis; therefore, these cells can grow and divide. When new daughter cells are produced, they push older cells away from the life-sustaining nutrients of the dermis toward the outer layers of the epidermis. As older cells travel from the basal to the superficial layers, they undergo profound changes: they fill with keratohyalin granules; lose their nuclei, cytosol, and organelles; and ultimately become lifeless sheets of keratin. This process is called keratinization and enables millions of dead cells to rub off or "exfoliate" daily at no expense to the animal's health. Keratinization is important because keratin is a tough, fibrous, waterproof protein that gives skin its resiliency and strength.

What adaptations are found in the snake skull that allow the ingestion of large prey?

The mandibular symphysis is not fused in snakes, but instead connected by ligaments. This flexible connection of the rostral mandibles allows the jaws to move independently of one another and literally "walk" forward when prey are ingested. Other adaptations include the presence of the quadrate bones, which allow the mouth to open very wide, and moveable bones that make up the maxillae and palate.

What is the manubrium?

The manubrium is the first, most cranial, sternebra

What is the basic difference between the functions of the mechanical and chemical respiratory control systems?

The mechanical system sets routine inspiration and expiration limits, and the chemical system monitors the levels of certain substances in the blood and directs adjustments in breathing if they get out of balance.

Differentiate between the medial and lateral surfaces of one of a dog's elbows and the proximal and distal end of one of its legs.

The medial surface is toward the center line of the animal's body, and the lateral surface is on the outer side of the elbow. The proximal part of the leg is closer to the body relative to, for example, the toes, which are located distally.

What is the mediastinum and what organs and structures are located there?

The mediastinum is the area between the lungs that contains most of the rest of the thoracic contents: the heart, large blood vessels, nerves, trachea, esophagus, and lymphatic vessels and lymph nodes.

What are the protective membranes that surround, support, and protect the CNS?

The meninges. These are a set of connective tissue layers that surround the brain and spinal cord. The three layers of the meninges, from outside to innermost layer, are the tough, fibrous dura mater, the delicate, spider web-like arachnoid, and the very thin pia mater, which lies directly on the surface of the brain and spinal cord.

What is the brush border in relation to the small intestine, and what is its function?

The microvilli on the villi of epithelial cells lining the small intestine. They increase the surface area of the intestinal lumen resulting in a greater surface for absorption. They also contain enzymes necessary for membranous digestion

What does the mitochondrion in the cell do?

The mitochondrion produces 95% of teh energy that fuels cellular activity. The energy is predominantly stored in the terminal phosphate bond of adenosine triphosphate (ATP) molecules. The ATP is derived from an array of biochemical processes using oxygen and nutrient molecules. Oxygen enters the body via respiration, and nutrient molecules are provided from food sources. Remarkably, mitochondria contain their own DNA, which includes the instructions for making the enzymes used to make ATP.

When is a membrane process considered active?

The movement of molecules and substances across the cell membrane is considered active when the process requires energy. Energy is stored in molecules such as adenosine triphosphate (ATP). Removal of the terminal phosphate in ATP releases the stored energy needed to drive an active membrane process.

Explain why waves of depolarization are conducted faster in myelinated axons than in unmyelinated ones.

The myelin sheath prevents sodium ions from flowing across the neuronal cell membrane. Therefore, depolarization in myelinated axons can only take place at the gaps in the myelin sheath that occur at the nodes of Ranvier. When the sodium influx at one node is sufficient to open adjacent sodium channels, the next available sodium channel is at the next node of Ranvier. The depolarization wave in the myelinated axon skips from one node of Ranvier to the next, greatly accelerating the rate at which the depolarization wave moves from the neuron cell body to the other end of the axon.

Describe the effect of a cardiac muscle's nerve supply on its functioning

The nerve supply to cardiac muscle does not initiate cardiac muscle cell contraction but it can modify the contraction

On which bone is the olecranon process found? What is its purpose?

The olecranon process forms the point of the elbow and is on the ulna. It is the site where the tendon of the powerful triceps brachii muscle attaches

Why is the optic disc the blind spot of the eye?

The optic disc contains only nerve fibers and a few blood vessels but no photoreceptor cells, so no visual images are formed there.

What is the origin of a muscle? The insertion?

The origin of a muscle is the most stable attachment site. The insertion of a muscle is the site that undergoes the most movement when a muscle contracts.

What does pH measure?

The pH of a solution is a measure of its acidity or alkalinity.

What surface of a hamster's front leg is in contact with the ground when it is walking normally? What surface of the hind leg?

The palmar surface of the front leg and the plantar surface of the hind leg are touching the ground.

What is the palpebral reflex? How is it used in veterinary medicine?

The palpebral reflex arc originates from receptors on the eyelid margins, travels via sensory neurons in CN V to the pons (brain stem), synapses with neurons in the pons, and then travels via CN VII to the muscles that blink the eyelids. If the reflex is active, a light tap on the medial canthus of the eye (the medial corner of the eye where the top and bottom eyelids meet) produces a blink of the eyelids. When an animal is anesthetized, the neurons in the pons become less responsive. Therefore, as anesthesia deepens, the palpebral reflex (also called the palpebral blink reflex) becomes less responsive and provides an indication of the animal's depth of anesthesia.

What does the ribosome in the cell do?

The ribosome is the site of protein syntehsis. Soluble protein intended for intracellular use is manufactured on free-floating ribosomes found throughout the cytosol, whereas protein intended for export outside the cell is synthesized on fixed ribosomes found on the rough endoplasmic reticulum (RER).

Why is the wall of the right ventricle thinner than the wall of the left ventricle?

The right ventricle doesn't have to pump as hard to get blood into pulmonary circulation as the left ventricle does to get blood into systemic circulation

How does each of the anatomic planes of reference (sagittal, median, transverse, and dorsal) divide a cow's body?

The sagittal plane divides the body into left and right parts, which are not necessarily equal. The median plane runs lengthwise down the center of the animal's body and divides it into equal left and right halves. The transverse plane divides the body into cranial and caudal parts, which are not necessarily equal. The dorsal plane divides the animal's body at a right angle to the sagittal or transverse plane and divides the body into dorsal and ventral parts, which are not necessarily equal.

Which eye structures are found in birds but not in mammals?

The sclerotic ring, the pectin, a second fovea, and colored oil droplets on the cones

By what mechanisms is inhaled air warmed, humidified, and filtered as it passes through the nasal passages? How do the turbinates aid these processes?

The scroll-like twists and turns of the turbinates tremendously increase the surface area of the nasal lining. They allow it to function as a combination radiator and humidifier. The air is warmed by the blood flowing through the complex of blood vessels just beneath the nasal epithelium and humidified by the mucus and other fluids that lie on the epithelial surface. The filtering function of the nasal passages helps remove particulate matter, such as dust and pollen, from the inhaled air before it reaches the lungs. The filtering mechanism relies on the many twists and turns of the nasal passages produced by the turbinates, the mucous layer on the surface of the nasal epithelium, and the cilia that project up into it. Air easily passes along the tortuous path of the nasal lining as it is inhaled, but particles of dust and other debris do not negotiate the twists and turns as readily and become trapped in the mucous layer. The beating of the cilia "sweeps" the mucus and the trapped foreign material back to the pharynx, where it is swallowed.

During depolarization, what ion channels open and what ion moves? Where does it move?

The sodium channels open and sodium ions move into the cell.

Both glucose and amino acids are brought into a cell through secondary active transport? What does this mean?

The sodium-potassium pump is creating a concentration gradient that favors movement of sodium into a cell. Glucose and amino acids can ride along with the sodium into the cell, even against a favorable concentration gradient.

What hormone plays an important role in helping an animal maintain its body temperature under cold environmental conditions? How does it produce its effects?

Thyroid hormone. It does this through its calorigenic effect. The production of thyroid hormone increases with exposure to cold temperatures. This response increases the body's metabolic rate, which generates more heat. It also causes nutrients to be burned at a faster rate; so to prevent significant loss of body weight, animals housed outdoors in cold temperatures need to be fed more calories than those kept in warmer temperatures.

Why is the timing of copulation so important? How is the precise timing accomplished?

Timing is important because the spermatozoa must arrive at the oviducts before the ovum to have time to undergo capacitation, a process that enhances their fertility. Nature has an exquisite method for arranging the proper timing. Breeding is only allowed by the female during the estrus, or heat, period. So spermatozoa enter the female reproductive tract when the oocyte in the follicle is fully developed but has not yet been released. Release of the ovum (ovulation) is delayed until near the end of the estrus period in most species. This nifty bit of traffic control helps ensure that the spermatozoa arrive at the oviducts first and have time to undergo capacitation before the ovum shows up ready to be fertilized.

Explain how sperm are transferred from the male to the female in birds?

To pass sperm to the female, copulation must occur. Copulation is achieved in one of two ways. In some species, such as ducks, geese, Galliformes, storks, and flamingos, a grooved erectile penis is attached to the wall of the cloaca to help transfer sperm into the female's vagina. However, in most species, sperm transfer occurs when the male and female bring their cloacae into close proximity.

Where is MALT found?

Tonsils (pharynx), adenoids (pharynx), Peyer's patches (intestines), and (in rabbits) the appendix (intestines), as well as clusters of lymphoid tissue in the gastrointestinal tract.

Is an animal with a body condition score (BCS) of 3/9 too fat or too skinny?

Too skinny. 5/9 is ideal. Lower values indicate the animal is underweight and higher values indicate the animal is overweight.

Why do touch and pressure sensations fade so rapidly from the conscious mind unless they change or are severe?

Touch and pressure sensations are not threats to the well-being of the animal and tend to fade from the conscious mind, allowing the CNS to focus on other more important sensations.

What are transamination and deamination?

Transamination occurs when the amine group from an amino acid is transferred to a different keto acid. In the process, a new and different amino acid is made. Deamination occurs when the amine group from an amino acid is removed from the amino acid molecule forming one molecule of free ammonia and one keto acid molecule.

Describe how nursing or milking causes milk let-down and also helps sustain lactation.

When milk is produced, it accumulates up high in the mammary gland in the alveoli and small ducts. It does not move down into the larger ducts and sinuses, where it is accessible for nursing or milking, until milk letdown occurs. Continued physical stimulation of the teat or nipple and regular removal of milk from the gland send sensory nerve impulses to the brain. From there nerve pathways lead to the hypothalamus, which stimulates the anterior pituitary gland to continue its production of the hormones that keep lactation going. It also causes the hypothalamus to release the hormone oxytocin from the posterior pituitary gland. Oxytocin travels to the mammary gland and causes musclelike myoepithelial cells around the alveoli and small ducts to contract. This squeezes milk down into the large ducts and sinuses, where it can be removed by nursing or milking. When nursing or milking stops, the flow of essential hormones stops also. The lack of hormonal stimulation combined with increased pressure in the gland (because it is no longer being emptied) causes lactation to gradually cease and the mammary gland to dry up. This is called involution of the mammary gland.

Which group of vertebrae make up the spinal columns dorsal to the following regions? a. abdomen b. neck c. pelvis d. tail e. thorax

abdomen: lumbar neck: cervical pelvis: sacral tail: coccygeal thorax: thoracic

Which plasma protein produced in the liver plays a crucial role in fluid movement between plasma and interstitial fluid?

albumin

Why is it important that uterine contractions continue after the fetus and placenta have been delivered?

Uterine contractions continue so that involution can occur. The contractions cause the sloughed endometrium to be expelled so that the sites where the placenta was attached can heal. Pressure from the continued uterine contractions usually stops bleeding relatively quickly.

Which layers of the eyeball are the iris and ciliary body part of?

Uvea

Describe how vaccines protect patients from disease. Is this an example of active or passive immunity?

Vaccines introduce a weakened form of a pathogen to which the animal's body mounts an immune response in which memory cells are produced. This allows the immune system to respond more quickly and effectively should it encounter the natural form of the pathogens. This is an example of active immunity.

What do vaults do in the cell?

Vaults are tiny, hollow transport complexes that are thought to attach to fibers in the cytoskeleton that enable rapid movement from one part of the cell to another. Vaults are able to open up and may lock into nuclear pore complexes on the nucleus, where they may pick up and drop off molecules.

What three factors influence the ability of a pathogen to cause disease?

Virulence of the pathogen and degree of pathogenicity Immune system strength Mode of infection/transmission

Why are visceral sensations important to the survival of an animal?

Visceral sensations keep the CNS informed about the overall prevailing conditions inside and outside the body. The result is the initiation of behaviors designed to ensure the well-being of the animal.

What is the building block for proteins?

amino acids

In the luminal phase of the chemical digestion of starches, which enzyme, secreted by the pancreas, is needed?

amylase

What is an exopeptidase?

an enzyme that breaks off amino acids at the end of a polypeptide chain

Cellular metabolism is divided into two categories. What are they?

anabolism and catabolism

What type of tooth will continue to grow throughout the life of an animal?

aradicular hypsodont

Is a solution with a pH of 8.5 acidic or basic?

basic

Which white blood cell is least commonly seen in peripheral blood?

basophil

What substance, released by the pancreas and liver into the duodenum, helps neutralize the acidic chyme leaving the stomach?

bicarbonate

What is another name for hydrostatic pressure in the body?

blood pressure

What part of the brain controls many autonomic functions related to cardiovascular, respiratory, and gastrointestinal functions?

brain stem

If individual muscle fiber contractions obey the all-or-nothing principle, how does an animal control the size and strength of its muscular movements?

by the number of fibers in a muscle that contract

What ion, released from the sarcoplasmic reticulum by a nerve impulse, starts the contraction process in a muscle fiber?

calcium

Where does carbohydrate metabolism begin in nonruminant animals?

carbohydrate metabolism begins with the breakdown of glycogen or glycerol in the liver

Repeating units of monosaccharides make up what?

carbohydrates

Which atoms make up the backbone of all lipid molecules

carbon

What is a gland?

cell or group of cells that has the ability to manufacture and discharge a secretion

Which category of temperature receptors is most critical to the long-term survival of an animal in very hot or very cold environmental conditions: the superficial receptors or the central receptors (Hint: Which is more critical to an animal's survival - keeping its skin and extremities from getting too hot or cold or keeping the core of its body from getting too hot or cold?)?

central receptors

What is the fluid called that bathes, cushions, and aids in transport of materials to and from the CNS?

cerebrospinal fluid

What parts of the brain is responsible for conscious thought and perception of sensations?

cerebrum

Give a specific example of a steroid.

cholesterol

Semiliquid, partially digested food that leaves the stomach and enters the duodenum is ___.

chyme

Which are found more commonly in mammalian cells: cilia or flagella?

cilia

What are the main differences between visceral smooth muscle and multi-unit smooth muscle?

Visceral smooth muscle is found in the walls of internal soft organs (viscera). The muscle cells are linked to form large sheets. Fine movements is not possible because the contractions are strong. Multiunit smooth muscles are small and delicate. They are made up of individual cells or small groups of cells. They are found where small, delicate contractions are needed.

How might vitamins play a role in enzyme-driven reactions?

Vitamins are nonprotein organic substances whose derivatives may act as cofactors, specifically called coenzymes. They may be bound temporarily or permanently to the enzyme and are usually located near the active site.

What is vitellogenesis?

Vitellogenesis is the process of adding vitellogenin, a lipid substance, to the yolk within the developing follicle. When certain environmental cues are encountered, estrogen and follicle-stimulating hormone are released, which causes development and maturation of the follicles via a process called vitellogenesis. Vitellogenin is formed from mobilized fat by the liver; thus during vitellogenesis the liver often takes on a yellow color. Large amounts of calcium are also added to the yolk during this process. Circulating calcium levels tend to be very high in reptiles during vitellogenesis because calcium is mobilized by bone to supply the developing follicles.

Why is water so vital to the survival of an animal?

Water is involved in almost all of the metabolic processes of the body. It is the major component of blood and is found inside all cells (intracellular) as well as outside the cell (extracellular). It is a lubricant for body tissues, a circulatory and transport medium, and a chemical reactant in digestion (hydrolysis). In addition, water is excreted as sweat and evaporated during panting to assist in temperature regulation. Finally, it is the medium in which the biochemical reactions of metabolism occur, such as those involved in the growth, repair, and maintenance of cells.

How are feces formed?

Water is removed from the chyme

The digestion of food uses which type of chemical reaction?

decomposition reaction

Why do changes in osmolality cause fluid to move from one compartment to another?

Water moves freely between fluid compartments based on changes in osmolality of the fluid in each compartment. Fluid moves toward the compartment with the highest concentration of solutes, and therefore the highest osmolality.

List four types of inorganic molecules that are important for life.

Water, salts, acids, bases

Name the typical parts of a typical neuron

dendrite, axon, cell body

What normally maintains the resting membrane potential of a neuron during the resting state?

distribution of positive and negative charges from sodium, potassium, proteins, and other charged ions on either side of the neuronal membrane, creating a difference in electrical charge across the membrane, with the inside of the neuron being more negatively charged than the outside. By selectively pumping sodium out and potassium in, the sodium-potassium pump maintains this negatively charged resting membrane potential

Name a common species of animal that has a short ascending colon?

dog, cat, any carnivore

Where does the common bile duct enter the small intestine?

duodenum through the sphincter of Oddi

In the membranous phase of chemical digestion of sugars, where are the necessary enzymes located?

embedded in the brush border of the intestinal epithelium

Which white blood cell would you likely see increased in peripheral blood during an allergic response?

eosinophil

Where are spermatozoa stored before ejaculation?

epididymis

What common species of domestic animal does not have a gallbladder?

equine

In what skull bone is the cribriform plate found?

ethmoid bone

What is the common term for adipose tissue?

fat

In what skull bone is the frontal sinus found?

frontal bone

What part of the monogastric stomach increases in size to accommodate a large meal?

fundus

What is the most common carbohydrate found in blood?

glucose

The major storage form a glucose is _______.

glycogen

What is a brood patch and how does it relate to incubation?

When a female bird is ready to lay her eggs, hormones stimulate the development of a brood patch, which is an area of skin on the lower abdomen where heat is transferred to the egg. The hen plucks the feathers in this area because of the influence of prolactin, and estrogen stimulates thickening and wrinkling of the epidermis and an increase in the size and number of blood vessels.

How do the kidneys respond to a decrease in blood pressure?

When blood pressure falls, the juxtaglomerular cells within the renal cortex release an enzyme called renin. Renin causes the formation of angiotensin I from angiotensin. Angiotensin I is subsequently converted to angiotensin II by another enzyme, angiotensin converting enzyme (ACE). Angiotensin II causes the arteries in the body to constrict. It also causes and the release of aldosterone from the adrenal gland, which is located near the kidney. Aldosterone stimulates the kidney to reabsorb sodium and water back into the bloodstream, which increases both blood volume and blood pressure.

What are the parts of a hair follicle?

hair bulb papilla matrix

When does the healing process begin?

healing begins with inflammation

What are the names of the male copulatory organs in snakes and lizards?

hemipenes

What characteristics of chyme are necessary to stimulate the release of cholecystokinin (CCK)?

high amino acid or fatty acid content, low pH

Which species of large animals is a hindgut fermentor?

horse or rabbit

Which lymphatic organ is large at birth and gradually gets smaller as the animal matures?

thymus

Which bone is larger and supports more of an animal's weight, the tibia or fibula?

tibia

What is the function of the chordae tendonae?

to prevent the AV valves from opening backward into the atria

Why does an animal breath heavily for a while after heavy exercise?

to replace the amount of oxygen that is used to convert lactic acid to glucose in the liver

What are the main functions of blood?

transportation, regulation, defense

What numeric system is used to assign a specific number to each tooth in the mouth?

triadan system

How many electron shells would an atom have if it had four electrons?

two

What nerve can elicit opposite types of gastric movement through the release of different neurotransmitters in the myenteric plexus?

vagus nerve

Where in the vertebra is the spinal cord located?

vertebral foramen formed by the vertebral arch and the vertebral body

What portion of a serous membrane covers the outer surface of organs?

visceral layer

The serous membrane that covers the organs of the abdominal cavity is the ____.

visceral peritoneum

What are the two most important senses in birds?

vision and hearing

The main source of energy in ruminants is the production of _____.

volatile fatty acids

What is the most abundant component of plasma?

water

The majority of the tongue is made up of what type of tissue?

muscle

What is the common name for the distal sesamoid bone in the horse?

navicular bone

What are the two basic cell types that make up neural tissue?

neurons and supporting neuroglial cells

Which white blood cell is known as "the second line of defense" after a microorganism has entered the body?

neutrophil

Which white blood cell is known as a PMN?

neutrophil

Describe the process of inflammation. What causes the clinical signs of heat, swelling, redness, and tenderness?

nflammation begins with a 5- to 10-minute period of vasoconstriction followed by a sustained period of vasodilation. The initial constriction occurs in the small vessels of the injured tissue and aids in the control of hemorrhaging. Histamine and heparin molecules released from mast cells stimulate vasodilation and increase permeability of capillaries. Blood flow to the area is increased, which in turn causes the clinical signs of heat and redness. Blood flow also increases the supplies of oxygen and nutrients to the active cells of the damaged tissue. Plasma fluid, composed of enzymes, antibodies, and proteins, pours into the affected area, causing swelling of the soft tissue structures. This swelling irritates delicate nerve endings and causes pain and tenderness in the affected area. Clot formation begins to take place, which slows bleeding. The clot also helps isolate the wound from the invasion of pathogens and helps prevent bacteria and toxins from spreading to surrounding soft tissue structures. A clot first forms when platelets become sticky and clump together. Fibrinogen, found in rich quantities in the swollen tissue, is converted to an insoluble protein called fibrin. Fibrin is woven into a netlike structure that surrounds the platelets and provides support and stability to the newly formed clot. It also forms a framework to support the movement of cells throughout the site. Clots that form on the skin eventually dry and become known as scabs. Large cells, such as macrophages and neutrophils (types of white blood cells), move through blood vessels and can squeeze through dilated capillaries to assist in the removal of debris and microinvaders. The phagocytic cells are short lived, however, and can function for only a few hours before dying. Pus, which is an accumulation of dead and degenerated neutrophils and macrophages, may therefore collect in the injured area. With increased blood flow, histamine and heparin are dispersed, and their levels drop in the affected area. The decrease in these molecules causes the return of normal capillary size and permeability. When capillaries return to normal size, blood flow and fluid leakage into the affected area abate. Swelling, heat, and redness begin to subside. To sum up the sources of the clinical signs accompanying inflammation: Heat and redness are caused by increased blood flow to the area. Swelling is caused by fluid from plasma, composed of enzymes, antibodies, and proteins, pouring into the affected area. This swelling irritates delicate nerve endings and causes pain and tenderness in the affected area.

Which neurotransmitter, released by sympathetic neurons, causes a reduction in the frequency of smooth muscle contractions in the stomach?

norepinephrine

In what skull bone is the foramen magnum found?

occipital bone

What is the largest sesamoid bone in the animal bode?

patella

What proteolytic enzyme in the stomach begins protein digestion?

pepsin

Which movement in the small intestine propels intestinal content toward the rectum?

peristalsis

What is the proper medial term for the throat?

pharynx

Which lipids are polar: neutral fats or phospholipids?

phospholipids

Name a common species of animal that has a spiral ascending colon shaped like a cone?

pig

Where is transitional epithelium found?

portions of the urinary tract where great changes in volume occur (urinary bladder, ureters, urethra, calyxes of the kidneys)

What are the cardinal signs of inflammation?

redness, swelling, pain, loss of function

Urea produced as a by-product of amino acid metabolism is in the ruminant liver goes to the ____ for reuse.

reticulorumen

If you are facing a cat head-on, is its left ear on your left or right side?

right side

What is the anatomical name for the shoulder blade?

scapula

Name the bones of the thoracic limb from proximal to distal

scapula, humerus, ulna, radius, carpal bones, metacarpal bones, phalanges (some species have sesamoid bones)

Which hormone, released in the duodenum, is responsible for decreased hydrochloric acid production in the stomach?

secretin

Proteins in ruminant diets are broken down extracellularly by peptidase into ____.

small peptide chains

Which gamete, the ovum or the spermatozoan, determines the genetic sex of the offspring when fertilization occurs?

spermatozoan

In what skull bone is the pituitary fossa found?

sphenoid bone

Which lymphatic organ is composed of white pulp and red pulp?

spleen

If a dog walks out of an air-conditioned house and lies in the sun on a hot summer day, which of its temperature receptors will signal the brain firs that the dog is getting hot: superficial receptors or central receptors?

superficial receptors

Unconjugated bilirubin in blood is not water soluble. How does it become water soluble?

t combines with the plasma protein albumin and is transported to the liver, where it is taken in by a hepatocyte. In the hepatocyte it is conjugated with glucuronic acid and becomes water soluble.

In what skull bone is the external acoustic meatus found?

temporal bone

Which skull bones house the middle and inner ear structures?

temporal bone

What does TMJ mean?

temporomandibular joint

Which is located more caudally in a standing pig, the apex or the base of the heart?

the apex

What is the name of the single bone found within the middle ear of a reptile?

the columella

Which sits closer to the base of the heart, the left atrium or the right ventricle?

the left atrium

Where is the GALT located?

the lining of the intestine

What part of the urinary bladder is under voluntary control and allows an animal to be housebroken?

the muscular sphincter around the neck of the bladder

Besides water, list three substances found in saliva?

Protein, electrolytes, IgA, glycoproteins, bicarbonate, enzymes

The ureter is continuous with wha structures in the kidney (except cattle)?

the renal pelvis

Where is the occlusal surface of a tooth?

the surface that faces the opposite dental arch

Describe three types of cartilage. What are their differences and similarities?

1. Hyaline cartilage: Hyaline cartilage is the most common type of cartilage in the body. It is composed of closely packed collagen fibers that make it tough but more flexible than bone. Macroscopically, hyaline cartilage resembles a blue-white, frosted ground glass. It is found in the growth plates of long bones, where it supports continued bone development and the extension of bone length. Hyaline cartilage is the most rigid type of cartilage and is enclosed within a perichondrium. 2. Elastic cartilage: Elastic cartilage is similar to hyaline cartilage but contains an abundance of elastic fibers, which form dense branching bundles that appear black microscopically. Elastic cartilage is found in the epiglottis of the larynx and in the pinnae (external ears) of animals. 3. Fibrocartilage: Fibrocartilage usually is found merged with hyaline cartilage and dense connective tissue. Like hyaline cartilage, it contains thick bundles of collagen fibers, but it has fewer chondrocytes and lacks a perichondrium. Fibrocartilage is found in the spaces between vertebrae of the spine, between bones in the pelvic girdle, and in the knee joint.

What are the six fundamental nutrients? Which ones generate energy when consumed?

1. proteins 2. fats 3. carbohydrates 4. vitamins 5. minerals 6. water

What are the three kinds of bone cells? What role does each play in the life of a bone?

1. Osteoblasts are the cells that form bone where it is needed. They secrete the matrix of bone and then supply the minerals necessary to ossify (harden) it. Once the osteoblasts become trapped in the ossified matrix they have created, they are called osteocytes. 2. Osteocytes are bone cells. 3. Osteoclasts eat bone away. Bones are dynamic structures that must be remodeled constantly. By removing bone from where it is not needed, osteoclasts make it possible for remodeling to take place. They also allow the body to withdraw calcium from the bones when it is needed to raise the calcium level in the blood.

What happens in each stage of mitosis?

1. Prophase: Chromatin coils and condenses into chromosomes that are visible with light microscopy. These chromosomes are composed of two identical chromatids linked together at a constriction in their middle known as the centromere or kinetochore. The cytoplasm becomes more viscous as microtubules from the cytoskeleton are disassembled and the cell becomes round. Two pairs of centrioles form anchors on which new microtubules are constructed, and as the microtubules lengthen, they push the centrioles farther and farther apart. In this way a mitotic spindle is formed that provides the structure and machinery necessary to separate the chromosomes. Because transcription and protein synthesis cannot occur while the DNA is tightly coiled, the appearance of chromosomes marks the cessation of normal synthetic processes. Prophase is thought to conclude with the disintegration of the nuclear envelope. 2. Metaphase: Chromosomes line up in the exact center of the spindle, known as the equator. The chromosomes are evenly spread apart and form what is called the metaphase plate midway between the poles of the cell. The centromere of each chromosome is attached to a single spindle fiber. 3. Anaphase: The centromeres of the chromosomes split apart and each chromatid becomes its own chromosome. The spindle fiber separates, each spindle segment shortens, and the twin chromosomes are pulled away from each another. The chromosomes take on a V shape as they are dragged at their midpoint toward the centrioles at opposite ends of the cell. The cell becomes elongated, and the cytoplasm begins to constrict along the plane of the metaphase plate. Although anaphase is the shortest phase of mitosis and usually lasts only a few minutes, its importance is clear in light of the devastating consequences if an error were to occur in chromosome separation. In anaphase the advantage of separating compact bodies of chromosomes, rather than long thin threads of chromatin, is particularly obvious. 4. Telophase: Begins when chromosomal movement stops. The chromosomes, having reached the poles, begin to unravel, elongate, and return to a diffuse threadlike form (chromatin). A nuclear envelope appears around each new set of chromosomes, and nucleoli appear in each nucleus. The microtubules that made up the spindle in the earlier phases of mitosis disassemble, and a ring of peripheral microfilaments begins to squeeze the cell into two parts. Ultimately, the cell pinches itself in half, dividing the cytoplasm and forming two completely separate daughter cells. The process of cytoplasmic division is called cytokinesis and marks the end of telophase.

List the four conductors that make up the rapid conduction system for an impulse created by the heart's pacemaker.

1. SA node 2. AV node 3. Bundle of His 4. Purkinje fiber system

What four attributes characterize epithelial tissue?

1. They are polar. Apical surface faces the lumen/body cavity, basal surface faces the underlying connective tissue. 2. They have lateral surfaces which connect them to neighboring cells by junctional complexes. These junctions bring the cells into close apposition to one another, leaving little room for extracellular matrix. the matrix that surrounds epithelia therefore exists in very small quantities - if at all. 3. All epithelial cells lack blood vessels or capillaries. Avascular, rely on underlying connective tissue to provide oxygen and nutrients. 4. Although some epithelia lack nerves (stomach, intestines, cervix), most are innervated and provide valuable sensory input.

List four types of cellular junction. Describe them.

1. Tight junction: formed by the fusion of the outermost layers of the plasma membranes of adjoining cells. The matrix-filled space between cells is lost at the site of a tight junction. For centrally placed cells, the fusion occurs as a strip that wraps around the entire circumference of the cell like a belt. In this way, an impenetrable barrier is formed that prevents the passage of substances from the luminal end to the basal end of the cell and vice versa. Only by passing through the body of the cell can substances pass through the epithelial layer. Tight junctions are found in tissues in which there can be no leaks—for example, in the urinary bladder, where urine is held, or in the digestive tract, where tight junctions play a critical role in preventing the leakage of digestive enzymes into the bloodstream. 2. Desmosome: strong, welded plaque that connects the plasma membranes of adjacent cells. The bond is a mechanical coupling formed by filaments that interlock with one another, just as plastic fibers do in Velcro. Tonofilaments, or intermediate filaments, may also extend from the desmosomic plaque into the cytoplasm of each cell like anchors, forming stabilizing bases for the membrane junction. In this way, desmosomes form tough bonds between cells and therefore are found most commonly in tissues that undergo repeated episodes of tension and stretching, such as the skin, heart, and uterus. 3. Hemidesmosome: junctions that look like half-desmosomes and link epithelial cells to the basement membrane. 4. Gap junction: made of tubular channel proteins called connexons and extends from the cytoplasm of one cell to the cytoplasm of another. These transmembrane proteins allow the exchange and passage of ions and nutrients (e.g., nucleotides, sugars, and amino acids) from one cell to another. Gap junctions are most commonly found in intestinal epithelial cells, the heart, and smooth muscle tissue. The function of gap junctions in epithelial cells is not yet fully understood, but their ability to quickly transport electrical signals from one cell to another explains their presence in cardiac and smooth muscle cells, where they help coordinate contraction.

What are the three most important volatile fatty acids produced by conversion from pyruvate?

1. acetate 2. propionic acid 3. butyric acid

List, in order, the structures an erythrocyte will pass through (including valves) to move in a complete circuit from the left ventricle back to the left ventricle

1. aortic valve 2. aorta 3. systemic circulation 4. vena cava 5. right atrium 6. tricuspid valve 7. right ventricle 8. pulmonary valve 9. pulmonary circulation 10. left atrium 11. mitral valve 12. left ventricle

What are the four sections of a monogastric stomach?

1. cardia 2. fundus 3. corpus (body) 4. pylorus

Give three examples of specialized connective tissue. How are they similar to connective tissue proper? How are they different?

1. cartilage 2. bone 3. blood Cartilage is similar to connective tissue proper in that it is composed of cells, fibers, and matrix. It is different in that it is more rigid than dense connective tissue. Bone is similar to connective tissue proper in that it is also composed of cells, fibers, and matrix; however, bone is much more dense. In fact, it is the hardest, most rigid type of connective tissue. Blood is similar in that it has a matrix, plasma, a fibrous component that is visible when blood clots, and cells. It is different in that it is almost always fluid but can clot when necessary.

List the four parts of the large intestine.

1. cecum 2. colon 3. rectum 4. anus

Name three structures that all mammalian cells possess.

1. cell membrane 2. cytoplasm (cytosol and organelles) 3. nucleus

Connective tissue is divided into two broad categories. What are they?

1. connective tissue proper 2. specialized connective tissue

Identify each of the following being controlled by the autonomic or the somatic nervous system and as being either sensory or motor: 1. conscious movement of the forelimb 2. slowing of the heart rate in response t an increased blood pressure 3. constriction fo blood vessels in the skin in response to cold temperatures 4. perception of pain from an injection of antibiotics 5. perception of the amount of acidity present in the duodenum

1. conscious movement of the forelimb = somatic, motor 2. slowing of heart rate in response to an increased blood pressure: autonomic; sensory for sensing the increased blood pressure and motor for lowing the heart rate 3. constriction of blood vessels in the skin in response to cold temperatures: autonomic; sensory for sensing the cold temperatures and motor for constricting the vessels 4. perception of pain from an injection of antibiotics: somatic, sensory 5. perception of the amount of acidity present in the duodenum: autonomic, sensory

Why is skin important? What six important functions does skin serve?

1. covers and protects underlying structures 2. forms a critical barrier between the delicate inner workings of the body and the harsh elements of the external world which prevents disiccation and reduces the threat of injury 3. skin assists in the maintenance of normal body temperature via sweating and shivering and the presence of features such as hair and sebaceous glands 4. excretes water, salt, organic wastes 5. important sensory organ that takes in info from the environment through touch and pressure and conveys this input to regions of the central nervous system 6. engaged in synthesis of vitamin D and the storage of nutrients

What are the three subtypes of dense connective tissue?

1. dense regular 2. dense irregular 3. elastic

List three conditions in the duodenum that can decrease the rate of gastric emptying.

1. duodenal distention 2. hyper/hypo-osmolarity of chyme 3. high concentration of protein or fat breakdown products, acidic chyme

What are the three basic constituents of connective tissue?

1. extracellular fibers 2. ground substance 3. cells

List three major functions of feathers.

1. flight 2. protection of the thin skin from trauma, rain, and excessive radiation from sunlight 3. thermoregulation, camouflage, and communication behaviors, such as courtship, defense, and recognition

List seven functions of connective tissue

1. forms metabolic and structural connections between other tissues 2. forms a protective sheath around organs 3. helps insulate the body 4. acts as a reserve for energy 5. provides the frame that supports the body 6. composes the medium that transports substances from one region of the body to another 7. plays a vital role in the healing process and in the control of invading microorganisms

List the three steps involved in performing urinalysis.

1. gross examination of the physical properties of the sample 2. chemical analysis of substances dissolved in the urine 3. microscopic examination of the solid components in the urine

What are the four types of tooth that make up heterodont dentition?

1. incisors 2. canines 3. premolars 4. molars

Where can a simple squamous epithelium be found? (2 places)

1. inner lining of the lung (where oxygen is absorbed and carbon dioxide released) 2. filtration membranes of a kidney (where water and other small molecules are excreted as urine)

What are the two types of digestion that take place in the stomach?

1. mechanical 2. chemical

What molecules are more likely to diffuse into a cell? What three principles are involved?

1. molecule size (H2O and other small molecules <0.8nm) 2. lipid solubility (alcohol and steroids, dissolved gases) 3. molecular charge (require specialized pores to allow ions to pass through but is selective)

What are the four major categories of lipids?

1. neutral fats 2. phospholipids 3. steroids 4. other lipoid substances

What three actions result from acetylcholine release during the cephalic phase of gastric secretion?

1. parietal cells release HCL 2. chief cells secrete pepsinogen 3. G cells secrete gastrin

What are the four movements associated with the large intestine?

1. peristalsis 2. antiperistalsis 3. segmentation 4. mass movement

What three structures are found in the triad location at the periphery of a hepatic lobule?

1. portal vein 2. hepatic artery 3. bile duct

Besides supporting the other tissues of the body, what else do bones do?

1. protect many delicate vital organs and tissues by surrounding them partially or completely 2. act as layers for the skeletal muscle to move the body. Attachment of skeletal muscles to bones via the tendons allows the muscles to move joints, enabling an animal to move about in its environment 3. act as storage site for minerals (particularly calcium) 4. sites for blood cell formation (hematopoiesis) in the bone marrow that fills their interiors

List seven functions of epithelial cells?

1. protect, cover, line tissues 2. filter biochemical substances 3. absorb nutrients 4. provide sensory input 5. manufacture secretions 6. manufacture excretions 7. act as an interface layer that separates and defines the beginning and ending of different types of tissues

How many types of fiber make up the cytoskeleton? Can you name them? How do they function differently.

3, all made of protein. The fibers are microtubules, intermediate fibers, and microfilaments. Microtubules form secure "cables" to which mitochondria, lysosomes, and secretory granules attach. Proteins that act as "motors" move the attached organelles along the microtubule from one location in the cell to another. Because microtubules act as the "railroad tracks" for organelle travel, they can be easily disassembled and then reassembled to form new paths or take a new direction. Intermediate fibers are woven, rope-like fibers that possess high tensile strength and are able to resist pulling forces on the cell by acting as internal guide wires. These fibers are the toughest and most permanent element of the cytoskeleton. Microfilaments play a key role in the cell's ability to change shape, break apart during cell division, and form outpouchings and involutions. In most cells, microfilaments are assembled where and when needed.

What is the body temperature range of brids?

37*C to 42*C

What is the maximum number of ATP molecules that can be formed from the catabolism of one molecule of glucose?

38

How do changes in the osmolality of body fluids affect an animal's desire to drink and its ability to concentrate or dilute urine?

A hormonal feedback loop helps maintain the osmolality of body fluids within a very narrow range. An increase in the osmolality of blood, for example, stimulates the desire to drink and the release of antidiuretic hormone (ADH) in the pituitary. ADH, in turn, stimulates the kidneys to resorb water from protourine resulting in the concentration of urine. The opposite happens if the osmolality of blood becomes too low. The release of ADH in the brain is repressed and urine becomes concentrated via active removal of water from protourine in the kidney

What is a mixture?

A mixture is a combination of two or more ingredients that are chemically unchanged when combined with one another. Mixtures can be homogeneous and heterogeneous.

What are the differences among a skeletal muscle fiber, a skeletal muscle myofibril, and a skeletal muscle protein filament?

A muscle fiber is one muscle cell. The muscle fiber is made up of many muscle myofibrils. Within the myofibrils are muscle the protein filaments myosin and actin

What is a mute? What can it tell us about the health of a bird?

A mute is a combination of excrement from the intestine, kidneys, and genital ducts that is ejected through the vent. Normally, mutes have a dark fecal center surrounded by a white ring of urates. Mutes are an important diagnostic tool in assessing overall health. Their color and consistency can be altered by diet, parasites, or disease, and any change in an individual bird's normal excreta should be investigated to discover the cause. For example, parrots fed a fruity, pelleted diet often have a variety of colors to their mutes, and hawks fed day-old cockerels will have gold fecal centers in their mutes instead of dark ones. These are normal changes and can be explained by diet. Birds with intestinal parasites, such as coccidia, often have a tinge of green (and sometimes blood) in their output. To obtain a diagnosis, a detailed history from the owner is necessary (if possible), as well as other diagnostic tests.

What is the result of a normal PLR?

A normal response to shining a light into the eye of an animal (pupillary light reflex [PLR]) is for the iris in both eyes to constrict, thus making both pupils smaller.

How many nitrogenous bases are there?

A nucleotide is the building block of nucleic acid (DNA and RNA). It is composed of three subunits: a nitrogenous base, a five-carbon sugar, and a phosphate group. There are five different nitrogenous bases: adenine (A), cytosine (C), guanine (G), uracil (U), and thymine (T). Adenine, cytosine, guanine, and thymine are found in DNA. Adenine, cytosine, guanine, and uracil are found in RNA. These five nitrogenous bases are further divided into two groups based on their molecular structure: purines and pyrimidines. Purines include adenine and guanine and have two rings in their molecular structure. Pyrimidines, which include thymine, cytosine, and uracil, are single-ringed molecules.

What defines a passive membrane process?

A passive membrane process is one that does not require energy (ATP).

What is a peptide?

A peptide is a molecule consisting of two or more amino acids in which the carboxyl group of one acid is linked to the amino group of the other.

What roles do the sensory receptors, sensory neuron, interneuron, and motor neuron play in the reflex arc?

A sensory receptor detects a change either in the external environment or within the body itself. Once stimulated to threshold, the sensory receptor sends an action potential (nerve impulse) along the sensory neuron to the gray matter of the spinal cord or brain stem. In the CNS gray matter, the sensory neuron synapses with other interneurons, which serve to integrate the incoming sensory impulse with other impulses from other sensory neurons. Finally, the integrated response of the reflex is sent out from the spinal cord or brain stem by the motor neuron, which ends at the target organ (muscle or endocrine gland).

How do histones play a role in gene regulation?

A single strand of DNA winds around eight histone molecules, forming a granule called a nucleosome. The nucleosomes are held together by short strands of DNA called linker DNA. Not only do the histone proteins help keep the DNA strand organized and untangled, but they also expose small sections of the DNA (genes) to the outside nucleoplasm. By changing shape, the histones can expose different sections of DNA, called genes, at different times. A gene is the length of DNA needed to make one peptide (a short chain of amino acids). The exposed genes determine what proteins will be made by the cell. In this way, histones play an important role in regulating gene expression (gene regulation). DNA contains the instructions required for synthesis of thousands of different proteins, but not all of them are made. Only a small percentage of the possible thousands of proteins are actually manufactured. Histones help determine which segments of DNA will be expressed and therefore which proteins will be made.

What is the sensory receptor in the stretch reflex? What results from the stretch reflex are stimulation? Is this an ipsilateral or contralateral reflex?

A specialized structure within the muscle called the muscle spindle. Muscle contraction results. Ipsilateral.

What is a urolith?

A stone anywhere in the urinary system (kidneys, ureters, urinary bladder, or urethra)

What happens in a withdrawal reflex? Is this reflex more or less complex than the stretch reflex?

A strong stimulus to a receptor causes the sensory somatic neuron to send impulses to the spinal cord. This reflex involves synapsing with several interneurons. Some of these interneurons will synapse with motor neurons that will cause contraction of a specific set of muscles responsible for pulling the limb away from the painful stimulus. Other interneurons will inhibit those opposing muscle groups so that the withdrawal of the limb is rapid and complete. This reflex is more complex than a stretch reflex.

What two bypass structures are round in the fetus that allow most of its blood to bypass the pulmonary circulation?

Foramen ovale and ductus arteriosus

Through what mechanisms does the hypothalamus control the production or release of hormones from the pituitary gland? How does it effects of the anterior and posterior portions of the pituitary differ?

A system of tiny blood vessels called a portal system links the hypothalamus with the anterior portion of the pituitary gland. Modified neurons in the hypothalamus secrete hormones into these portal blood vessels. The hormones travel the short distance down to the anterior pituitary and regulate much of its function. These hypothalamic hormones, called releasing and inhibiting factors, are each specific for a particular anterior pituitary hormone. As their names imply, a releasing factor causes the anterior pituitary to produce and release a particular hormone, and an inhibiting factor has the opposite effect of inhibiting the production and release of a hormone. Because some anterior pituitary hormones influence all of the body's cells, the hypothalamus indirectly affects the whole body by regulating anterior pituitary gland functions. The effect of the hypothalamus on the posterior part of the pituitary gland is more direct. Modified neurons in the hypothalamus produce two hormones, antidiuretic hormone and oxytocin, that are transported down nerve fibers to the posterior pituitary gland, where they are stored. They are then released into the bloodstream by nerve impulses from the hypothalamus.

What is the difference between a tendon and an aponeurosis?

A tendon is a band of fibrous connective tissue that attaches muscle to bone. An aponeuroses is a broad sheet of fibrous connective tissue.

How does an ATP molecule differ from a nucleotide?

ATP is an RNA nucleotide containing the nitrogen base adenine with two additional phosphate groups attached.

Describe the following joint movements a. abduction b. adduction c. circumduction d. extension e. flexion f. rotation

Abduction: moves limb laterally away from the median plane Adduction: brings the limb toward the body Circumduction: movement in a circular manner (wrist moving in a circle) Extension: dorsal and ventral movements (ventral = extension) Flexion: dorsal and ventral movements (dorsal = flexion) Rotation: vertebral column, pivot joint, ball-and-socket joints

How is acetylcholine different from acetylcholinesterase?

Acetylcholine is a neurotransmitter broken down quickly by an enzyme called acetylcholinesterase found on the postsynaptic membrane. The broken down components of acetylcholine are reabsorbed by the synaptic knob, reassembled into new acetylcholine molecules, and repackaged into vesicles for release with the next wave of depolarization.

Which type of compound is known as a proton donor: Acid or base?

Acid

Can a cell that does not contain a nucleus live as long as a cell that does contain one?

All cells have different life spans: some are very short lived, while other cells live a long time. However, a cell that lacks a nucleus does not have the instructions (DNA) to make protein and therefore it cannot repair itself and will die sooner than if it had the ability to repair and maintain itself.

What are the four basic components of an amino acid molecule? Which parts of the molecule change to create the different kinds of amino acids?

Amino acids are composed of a central carbon atom, an amino group (NH2), a carboxyl group (COOH), and a variety of side chains ("R" group). Differences in the "R" group make each amino acid unique.

What is the principal building-block unit of proteins? How are these arranged?

Amino acids are the principal building blocks of proteins. They are arranged like pearls on a string. The acid group from one amino acid links to the basic group on the next, forming a peptide bond.

Stroke volume (SV) is a measurement of what?

Amount of blood ejected from the left ventricle during one contraction.

How many cardiac chambers do noncrocodilian reptiles and amphibians have?

Amphibians and most reptiles have three-chambered hearts with two atria and one common ventricle. The single ventricle functions as a four-chambered heart, however, so oxygenated and deoxygenated blood never mixes. Crocodilians are the only reptiles that possess four-chambered hearts.

Define ectothermic in reptiles and amphibians?

Amphibians and reptiles are commonly referred to as ectothermic or cold blooded. Ectothermic animals are unable to generate body heat internally; therefore, their body temperatures are dependent on environmental temperatures.

What is the average incubation temperature?

An average incubation temperature for many species is 35° C.

What is a preferred optimal temperature zone for reptiles?

An ectotherm's ability to effectively thermoregulate is entirely dependent on access to temperatures within the animal's preferred optimal temperature zone (POTZ), which is a range of temperatures in which the animal can perform all necessary metabolic functions. This principle becomes very important when maintaining herptiles in captivity. If not provided with an appropriate thermal gradient, a herptile will not be able to thermoregulate efficiently. When provided with inappropriately low temperatures, ectothermic animals can suffer from digestive problems, immunosuppression, and other disorders. If kept at temperatures that are too high, the animals are forced to maintain a high metabolic rate and may suffer from energy deficits.

What is an electrolyte?

An electrolyte is a charged particle (an anion or a cation) capable of conducting an electric current in solution.

What is an element?

An element is matter that cannot be divided by ordinary chemical processes into another substance.

Cellular respiration is composed of what two parts?

Anaerobic (glycolysis) and aerobic respiration (Krebs cycle and the electron transport chain)

Will the volume or gross appearance of the semen of an animal that has had a vasectomy be significantly different from that of a normal animal? Why or why not?

Because sperm typically account for less than 1% of seminal fluid, their absence after a vasectomy is negligible in terms of both amount and gross appearance of the seminal fluid.

How do the clinical signs of hypothyroidism and hyperthyroidism relate to the normal functions and thyroid hormone?

Because thyroid hormone influences the functioning of all cells, organs, and systems, hypothyroidism affects the whole body. Clinical signs relate primarily to a slowing of the body's metabolism and include alopecia (hair loss, usually bilaterally symmetrical), dry skin, lethargy, reluctance to exercise, and weight gain without any increase in appetite. An affected animal often seeks out sources of heat because deficient thyroid hormone levels cause the animal to have difficulty maintaining its body temperature. Most cases of hypothyroidism occur in middle-age animals, but if it occurs in a young animal, dwarfism (impaired growth) and impaired mental development occur along with the other common signs. Hyperthyroidism is most commonly seen in cats, although it is seen occasionally in dogs. Excessive amounts of thyroid hormone speed up cellular metabolism all over the body. This results in signs such as nervousness, excitability, weight loss, increased appetite, tachycardia (abnormally fast heart rate), vomiting, diarrhea, polyuria (excessive urine production), and polydipsia (excessive thirst).

Describe the importance of colostrum to the health of a newborn animal.

Before producing actual milk, the mammary gland produces colostrum, which contains larger amounts of proteins, lipids, and amino acids than milk and also contains high levels of various essential vitamins. Colostrum supplies important nutrients to the newborn and has a laxative effect that helps clear the dark, sticky meconium from the newborn's intestinal tract. In addition, colostrum provides antibodies that provide passive immunity for the newborn. These antibodies are specific for disease-causing organisms that the dam has been exposed to or vaccinated against. If the newborn drinks sufficient colostrum during the first few hours after birth, the large antibody molecules will be absorbed intact into its bloodstream and defend the animal against specific diseases. If colostrum is not consumed within the first few hours, the lining of the newborn's intestine can no longer absorb the large antibody molecules intact. They will be broken down by the digestive process, and passive immunity will not be transmitted. These animals may die of early infections, or they may be weaker and not grow as rapidly as animals that consume colostrum at the appropriate time.

List the two types of skeletal muscle fiber and describe their energy use.

Birds have white or red muscle fibers. White fibers are thick in diameter, have a low blood supply and little myoglobin (for carrying oxygen), and use stores of glycogen to sustain muscle contraction. They predominate in the flight muscles of short-distance fliers such as chickens, quail, grouse, and other gallinaceous birds that have rapid takeoffs but are capable of only short flights. If these birds are forced to fly repetitively, they quickly become fatigued and cannot fly at all until they recover. In contrast, red fibers are thinner and have a rich supply of blood, fat, myoglobin, and mitochondria. Using these components, they can produce enough energy to sustain muscle contractions for long periods. Red fibers are found in the flight muscles of long-distance fliers, including many species of songbirds, water birds, pigeons, and birds of prey.

Even though blood and bones appear to be grossly different, they both represent types of connective tissue. Why?

Blood and bone both contain cells, a matrix, and extracellular fibers.

How does the blood in the efferent glomerular arteriole differ from the blood in the afferent glomerular arteriole?

Blood in the afferent glomerular arteriole of the kidney gives up all of the small molecules that can fit easily through fenestrations in the glomerulus. These include electrolytes, bicarbonate, glucose and water. Consequently, the blood of efferent glomerular arterioles is composed of large molecules such as proteins and blood cells including platelets. An exception is oxygen, which is not given up by the red blood cells until the blood has entered the efferent arteriole. Here oxygen nourishes the cells of the nephron. Ultimately, the valuable electrolytes, buffers, glucose and water needed by the body are resorbed by the nephron and put back into the blood stream.

What is bone marrow, and what is the difference between the red kind and the yellow kind?

Bone marrow fills the spaces within bones. This includes the small spaces between the spicules of cancellous bone and the large spaces within the diaphyses of long bones. Red bone marrow is the part of the bone that forms blood cells. It makes up the majority of the bone marrow of young animals but only a small portion of the marrow of older animals. Yellow bone marrow is primarily made up of adipose connective tissue (fat). It is the most common type of marrow in adult animals. Yellow bone marrow does not produce blood cells, but it can revert to red bone marrow if the body needs to churn out larger than normal numbers of blood cells.

Name the skull bones that make up the bones of the ear

Bones of the ear: malleus, incus, stapes

How are the senses of taste and smell similar? How are they different?

Both are chemical senses. Whereas many nonhuman animals have less perceptive eyesight but a highly acute sense of smell, humans have a less perceptive sense of smell and a highly acute sense of taste.

How is the functioning of the vestibule and the semicircular canals similar? How is it different?

Both have endolymph- and perilymph-filled structures. The crista of the semicircular canals is similar to the macula of the vestibule. Both have supporting cells and hair cells with their processes (modified dendrites) sticking up into a gelatinous structure. However, there are no otoliths in the semicircular canals to weigh down the cupula. Instead, it functions as a float that moves with the endolymph in the membranous canal. Whereas the vestibular system senses rotary motion of the head with the semicircular canals, the vestibule senses linear motion and position of the head.

In what ways are the functions and characteristics of the endocrine system similar to those of the nervous system? In what ways are they different?

Both systems regulate body functions to maintain homeostasis. The endocrine system's reaction to stimuli is slow, whereas the reaction of the nervous system to stimuli is fast. The endocrine system's duration of effects is long, whereas the duration of effects of the nervous system is short. The target tissues for the endocrine system are virtually all body cells and tissues, whereas the target tissues for the nervous system are muscle and glandular tissues. The chemical messengers of the endocrine system are hormones, whereas the chemical messengers of the nervous system are neurotransmitters. The messenger-producing cells of the endocrine gland are cells or modified neurons, whereas the messenger-producing cells of the nervous system are neurons. The distance from chemical message production to the target for the endocrine system is long (via the bloodstream), whereas this distance for the nervous system is short (across the synaptic space).

What is the difference between breathing and respiration?

Breathing (ventilation) is the process of drawing air into the lungs and blowing it back out again. Respiration is the process of exchanging oxygen and carbon dioxide.

Describe how the mechanical respiratory control system maintains an ormal, rhythmic, resting breathing pattern.

Breathing is controlled by the medulla oblongata of the brain stem in an area called the respiratory center. Within the respiratory center are individual control centers for functions such as inspiration, expiration, and breath-holding that receive input from stretch receptors in the lungs that indicate when the lungs reach preset inflation and deflation limits. These centers send nerve impulses out to the respiratory muscles at a subconscious level, directing when and how much they contract. Therefore, the voluntary respiratory muscles are controlled by nerve impulses from a subconscious part of the brain.

Which amphibians do not have teeth?

Bufonid toads do not have teeth

Why might it be of clinical importance to know the origin and insertion of a muscle?

By knowing the origin and insertion of a muscle, you can predict the action of the muscle without actually seeing the muscle contract.

What are CAMS and what do they do?

CAM refers to cell adhession molecules, which are sticky glycoproteins (part of the glycocalyx) that cover the surfaces of almost all cells in mammals and allow them to bond to extracellular molecuels and to each other. These molecules are also important in helping cells move past one another and in signaling circulating cells, such as white blood cells, to areas of inflammation or infection.

What is gluconeogenesis and where in the ruminant does it mostly take place?

production of glucose from noncarbohydrate sources, liver

What are the main differences between the structures of cancellous bone and compact bone? Why does the body need these two different types of bone?

Cancellous bone consists of tiny spicules of bone randomly arranged with lots of spaces between them. In life, the spaces between spicules are occupied by bone marrow. To the naked eye, the many spicules and spaces give cancellous bone its spongy appearance. It is light but amazingly strong and helps reduce the weight of the bones of the skeleton without significantly reducing their strength. The organization of the spicules of cancellous bone may appear random, but spicules are actually arranged to stand up to the forces the bone is subjected to. Alternatively, compact bone is very heavy and dense. It is composed of tiny, tightly compacted cylinders of bone called haversian systems. Each haversian system runs lengthwise along the bone and consists of a laminated (multilayered) cylinder composed of concentric layers of ossified bone matrix arranged around a central canal. The haversian canal contains blood and lymph vessels and nerves that supply the osteocytes. The osteocytes are located at the junctions between the layers of bone that make up each haversian system. Two different types of bone are important because cancellous bone keeps an animal's body weight lower, being lighter than compact bone. Both types of bone are needed to stand up to the stresses encountered by an animal's skeleton.

List four types of organic molecules that are important for life.

Carbohydrates, lipids, proteins, nucleic acids

What three elements are found in all carbohydrates?

Carbon Hydrogen Oxygen

What three elements are found in all lipids?

Carbon Hydrogen Oxygen

What features does carbon possess that makes it particularly well suited for creating the chemistry of living creatures?

Carbon is electrically neutral and can form four covalent bonds with other atoms, including other carbon atoms. It can take on a linear structure or a ring structure from which functional groups extend.

What is the primary diet of a carnivore, an omnivore, and an herbivore?

Carnivore = meat Omnivore = both meat and plants Herbivore = plants

What are catecholamines?

Catecholamines are the neurotransmitters norepinephrine, epinephrine, and dopamine.

Give examples of both cations and anions.

Cations: potassium, magnesium, calcium, sodium. Anions: hydrogen phosphate, chloride, bicarbonate, sulfate

Where are anal sacs found and what is their importance to animals?

Cats and dogs have anal sacs that are located at the 5 and 7 o'clock positions relative to the anus. They are connected to the lateral margin of the anus by a small, single duct. The anal sac is lined with sebaceous and apocrine glands and acts as a reservoir for the secretions produced by these glands. When the animal defecates or becomes frightened, some or all of the anal sac contents are expressed. In this way, feces become coated with the secretions stored in the anal sac, and the unique smell of the animal is transferred to the environment. Thus defecation serves the dual purpose of elimination and of marking a territory or attracting a mate.

Why must the term rostral be used instead of cranial to describe structures on a hedgehog's head, but the term caudal works just fine?

Caudal always means toward the tail end of the body. The cranium is part of the head; therefore, the term cranial loses its meaning. Rostral specifically means toward the tip or nose.

When the mitral valve is forced closed it produces part of which heart sound, the first or the second?

First sound (the sound of the AV valves closing).

When does the chemical respiratory control system kick in and override the mechanical control system?

Chemical receptors in blood vessels (the carotid and aortic bodies located in the carotid artery and aorta, respectively) and in the brain stem constantly monitor various physical and chemical characteristics of the blood. Three characteristics important to the control of the breathing process are (1) the CO2 content, (2) the pH, and (3) the O2 content of the arterial blood. If any of these varies outside preset limits, the chemical control system signals the respiratory center to modify the breathing process to bring the errant level back into balance. If the chemical control system detects a rise in the blood level of CO2 and a decrease in the blood pH (blood becomes acidic), it signals the respiratory center to increase the rate and depth of respiration so that more CO2 can be eliminated from the lungs. If the CO2 level falls too low, which is usually accompanied by a rise in the blood pH level, the opposite occurs (that is, respiration is decreased to allow the CO2 level to rise back into the normal range). The effects of variations in the blood O2 level are not as clear cut as the CO2 effects. If a slight decrease in the blood O2 level (hypoxia) occurs, the chemical control system signals the respiratory center to increase the rate and depth of breathing so that more O2 will be taken in. If, however, the blood O2 level drops below a critical level, the neurons of the respiratory center can become so depressed from the hypoxia (lack of oxygen) that they cannot send adequate nerve impulses to the respiratory muscles. This can cause breathing to decrease or stop completely.

What does a cow do when she chews her cud?

Chewing the cud is the same as rumination

How are cilia and flagella different?

Cilia occur in large numbers on the exposed surface of some cells. They are shorter than flagella and measure only about 10m long. They move synchronously, one after the other, creating waves of motion that propel fluid, mucus, and debris across the cell surface. Cilia are best known for their important functions (1) in the upper respiratory tract, where they propel bacteria and mucus away from the lungs and (2) in the oviduct, where their beating motion pulls the ovulated egg away from the ovary and into the opening of the oviduct. Flagella generally occur singly and are significantly longer than cilia. They are typically attached to individual cells and propel the cell forward by undulating. Flagella move cells through fluid, whereas cilia move fluid across cell surfaces. The tail of a sperm cell is an example of a flagellum.

Compare and contrast collagenous, reticular, and elastic fibers.

Collagenous fibers are strong, thick strands composed of the structural protein collagen. Collagen fibers are organized into discrete bundles of long, parallel fibrils, which in turn are composed of bundled microfibrils. Because they possess tremendous tensile strength enabling them to resist pulling forces, collagenous fibers are found in tendons and ligaments that are continually being pulled and stretched. When not under pressure, collagenous fibers look wavy. The fiber itself is white, and the tissue it forms when the fibers are packed closely together is also white. Therefore, it is not surprising that collagenous fibers are sometimes known as the white fibers. Reticular fibers, like collagenous fibers, are composed of collagen, but they are not thick. Instead they are thin, delicate, and branched into complicated networks. Reticular fibers form a kind of "mist net" (rete is Latin for "net") that provides support for highly cellular organs such as endocrine glands, lymph nodes, spleen, bone marrow, and liver. Elastic fibers are composed primarily of the protein elastin. Like reticular fibers, elastic fibers are branched and form complex networks, but they lack the tensile strength of collagenous fibers. Elastic fibers are composed of bundles of microfibrils, and because they are coiled, they can stretch and contract like a rubber band. Therefore, elastic fibers tend to occur in tissues that are commonly subjected to stretching (vocal cords, lungs, skin, and walls of blood vessels). Because of their color, elastic fibers are sometimes referred to as the yellow fibers.

Why is it important for chromatin to coil and form discrete chromosomes before cell division?

DNA is a very long, cumbersome, and delicate molecule. The formation of duplicate, supercoiled chromosomes is essential for life and enables the cell to divide its genetic material equitably for a new generation, without tangling or breaking the long, delicate chains of genetic code.

Why is DNA important for life?

DNA is the molecule that contains all the instructions needed by the cell to build protein. These instructions determine the shape and function of every tissue in the body and, therefore, the shape and function of the living organism.

Explain the structure of DNA.

DNA molecules consist of two parallel strands of the nucleotides A, G, C, and T. The strands are connected by hydrogen bonds between the nitrogenous bases. Each nitrogenous base can hydrogen bond with only one other speicifc nitrogenous base. Adenine can bond only with thymine, and guanine can only bond with cytosine. The two strands of bonded nucleic acid twist around each other in a spiral called a double helix. The order of the nucleotids is unique to each individual and is carried in every cell of the individual.

When in the cell cycle does DNA replication occur?

DNA replicates during the synthetic (S) phase of interphase.

How could mitral valve stenosis affect the stroke volume?

Decrease stroke volume because the valve is not opening all the way so less blood is being delivered to the ventricle. In other words, the preload will decrease.

What process joins multiple simple sugars?

Dehydration synthesis

How are the dendrites and axons different in structure and function?

Dendrites receive stimuli, or impulses, from other neurons and conduct this stimulation to the cell body. Dendrites also may be modified into sensory receptors that receive, or sense, stimuli, such as heat, cold, touch, pressure, stretch, or other physical changes from inside or outside the body. Dendrites tend to be short, numerous, multibranched projections extending from the cell body. The axon conducts nerve impulses away from the cell body toward another neuron or an effector cell (a cell that does something when stimulated, such as a muscle or gland cell). In contrast to the short, numerous, branched dendrites, the axon is a single structure that can be very long. For example, a single axon in the horse may extend several feet from the spinal cord all the way to the lower leg. Axons are often covered by a fatty substance called myelin.

What substance makes up the bulk of a tooth?

Dentin

What are the main muscles of inspiration? How do they cause air to be drawn into the lungs?

Diaphragm and external intercostal muscles. When the diaphragm contracts (flattens), the thoracic cavity enlarges and the lungs expand. The fibers of the external intercostal muscles are oriented obliquely so that when they contract, they rotate the ribs upward and forward, thus increasing the size of the thoracic cavity.

What part of the brain serves as a relay station for impulses going to and from the cerebrum?

Diencephalon

Name two conditions that can predispose an animal to urolith production.

Diet and the presence of certain bacteria associated with urinary tract infections can influence the pH of urine to favor the precipitation of crystals and, eventually, uroliths. A housebroken animal that must consistently hold its urine for long periods of time has a decreased crystal transit time through the lower urinary tract (bladder and urethra) and is predisposed to urolith production.

Which type of placental attachment to the uterus is the simplest and detaches most easily after parturition? Which is most complicated and most often results in retention of the placenta?

Diffuse attachment is the simplest and detaches most easily. Cotyledonary attachment is the most complicated type and often results in retention of the placenta.

How are paw pads and the planum nasale different from other regions of skin?

Digital pads are formed by thick layers of fat and connective tissue that bear the weight of the animal. The pad's outer surface is the toughest and thickest skin in the body. It is often pigmented and is composed of all five epidermal layers. Of these five layers, the outermost epidermal layer, the stratum corneum, is thicker than all the others combined. This tough outer skin together with insulating fat forms a protective barrier against abrasion and thermal variances, enabling the animal to walk on rough surfaces, hot roads, and cold snow. The surface of the pad feels rough, and an uneven surface is visible to the naked eye. The pad is composed of exocrine sweat glands and lamellar corpuscles. Histologically, the ducts from these sweat glands can be seen passing through the dermis to the stratum basale of the epidermis. Their glandular excretion is then excreted onto the surface of the pad. The planum nasale is usually pigmented and appears to be a tough, thick region of integument histologically; however, the planum nasale in the dog is composed of only three epidermal layers, with the stratum lucidum and stratum granulosum absent. The outermost layer, the stratum corneum, is composed of only four to eight cell layers, surprisingly thin considering the exposed location of the nose and its heavy use, particularly in the dog. The epidermal surface of the planum nasale is divided by deep surface grooves, giving it the appearance of being composed of multiple plaques. As with other regions of the skin, the dermis and epidermis interdigitate to form an irregular line of attachment that includes dermal papillae. Although often moist from nasal secretions and licking, the planum nasale in the dog contains no glands in the epidermis or dermis. However, in the sheep, pig, and cow, tubular glands are found.

List, in order as they leave the stomach, the three sections of the small intestine.

Duodenum, jejunum, ileum

What are the basic events of the three trimesters of pregnancy?

During the first trimester, the newly implanted zygote is getting itself organized and developing its life-supporting placenta. The developing offspring is often referred to as an embryo. During the second trimester, the developing offspring is usually called a fetus. This is the fetal development period, when all of the various parts of the fetus (tissues, organs, and systems) are taking shape and differentiating from each other. The third trimester is the period of fetal growth, when all parts of the fetus grow dramatically as it prepares to become a free-living being after birth.

What is a substrate? What is a product?

Each enzyme reacts with a particular molecule called a substrate to produce a new molecule called a product.

What is the difference between endocrine and exocrine glands? Give examples of each

Endocrine glands do not have ducts or tubules, and their secretions are distributed throughout the body. They produce and secrete regulatory chemicals known as hormones into the bloodstream or the lymphatic system, where they are carried to many regions of the body. The pituitary gland in the brain and the adrenal gland near the kidney are examples of endocrine glands. Exocrine glands possess ducts. They are more common than endocrine glands and act by discharging secretions through their ducts directly into local areas, where they may cover cell surfaces or empty into body cavities. The secretions of exocrine glands act locally and do not normally enter the circulation. Examples include hepatoid, musk, sweat, and salivary glands. Exocrine glands in the liver secrete bile. The pancreas has both endocrine and exocrine glands.

How do endocrine glands differ from exocrine glands?

Endocrine glands secrete tiny amounts of hormones directly into the bloodstream and not through ducts. This feature differentiates them from exocrine glands, which secrete their products onto epithelial surfaces through tiny tubes called ducts.

Is energy produced or consumed during an anabolic process? What is an example of anabolism?

Energy is consumed during the anabolic process. Examples include the production of fat molecules by combining glycerol and fatty acid molecules, and the creation of proteins by joining amino acids.

How is energy stored in molecules? When is it released?

Energy is stored in the atomic bonds of molecules such as ATP, NADH, and FADH2. In these convenient molecular packages, energy can be stored for extended periods and easily transported to regions of the cell where energy is in demand. Energy is released when part of the molecule is broken off. For example, in ATP, energy is released when a phosphate group breaks off.

Why are enzymatic reactions considered highly specific?

Enzymatic reactions are highly specific because one enzyme reacts with one substrate or combination of substrates.

Why is the total number of enzymes present in the body relatively low, when compared with the number of metabolic reactions?

Enzymes are recycled and used over and over again. Once an enzyme has catalyzed one reaction, it is free to catalyze another reaction. In this way, a few enzymes can carry out many metabolic reactions.

How does an enzyme work?

Enzymes speed up or catalyze chemical reactions without being destroyed or altered. Enzymes are specific to the reaction they catalyze and the substrates (the substances they act upon) they use.

What is the structure that covers the opening of the trachea when an animal is swallowing food?

Epiglottis

Where would you find an epiphyseal plate, and what would you find it doing?

Epiphyseal plates (growth plates) are two areas of a long bone that remain as cartilage when an animal is born. Located between the shaft (diaphysis) of the bone and the ends (epiphyses) of the bone, they are the sites where the creation of new bone allows the long bones to lengthen as an animal grows.

Membranes are composed of what two tissue types?

Epithelial and connective tissue

List three fluid compartments in the body

Fluid compartments in the body include: intracellular, interstitial, and intravascular.

Compare and contrast connective tissue and epithelial tissue.

Epithelial and connective tissue are similar in that they may be linked to form membranes in the body. Membranes are thin, protective layers that line body cavities, separate organs, and cover surfaces. They are composed of a multicellular epithelial sheet bound to an underlying layer of connective tissue. Unlike epithelial tissue, connective tissue is composed primarily of nonliving extracellular matrix. Although epithelial tissue has no direct blood supply, connective tissue is vascularized; however, the level of vascularity varies among different connective tissue types.

What are the four basic tissues that make up an animal body?

Epithelial, connective, muscle, nervous

What are the four primary types of tissues?

Epithelial, connective, muscle, nervous

Explain the difference between eructation and rumination.

Eructation is the process by which gas produced by the fermentation process is released from the reticulorumen and passed up the esophagus and into the trachea, where it is expelled during expiration. Rumination is the process by which food is brought back to the oral cavity by antiperistalsis in the esophagus. The purpose is to chew the food more thoroughly and to add more saliva.

What is the name of the process that produces erythrocytes? Thrombocytes? Leukocytes?

Erythrocytes = erythropoiesis Thrombocytes = thrombopoiesis Leukocytes = leukopoiesis

How does a red blood cell carry oxygen to tissues?

Erythrocytes carry oxygen to tissues through the production of the protein hemoglobin that binds with the oxygen. Hemoglobin is a protein composed of two components - heme and globin. Every heme group can carry a molecule of oxygen. Four heme groups attach to each globin molecule, so each hemoglobin molecule can carry four molecules of oxygen. The oxygen attaches to iron atoms (Fe++) that are part of each heme group.

How do avian red blood cells differ from those in mammals?

Erythrocytes of birds are oval, nucleated, and larger than those in mammals.

Some amino acids cannot be synthesized in the body and must be provided in the diet. What are these amino acids called? Can you give an example of one in cats? Can you give an example of one in birds?

Essential amino acids cannot be synthesized in the body. Taurine is an essential amino acid for cats. Glycine is essential for birds.

What is an essential fatty acid?

Essential fatty acids are ones that the body cannot manufacture and must be provided in the diet.

What is the difference between an excitatory and an inhibitory neurotransmitter?

Excitatory neurotransmitters have an excitatory effect on the postsynaptic membrane when they combine with their specific receptors. Specifically, excitatory neurotransmitters usually cause an influx of sodium so that the postsynaptic membrane moves toward threshold. If the postsynaptic membrane is stimulated sufficiently by enough excitatory neurotransmitters, threshold will be attained and depolarization of the postsynaptic membrane will occur. In contrast, inhibitory neurotransmitters tend to hyperpolarize the postsynaptic membrane, making the inside of the cell more negative instead of positive and moving the charge within the postsynaptic cell farther away from threshold. When inhibitory neurotransmitters combine with their specific receptors on the postsynaptic side, they may cause chloride channels or potassium channels to open up on the postsynaptic membrane. This allows the negatively charged chloride ions (Cl) to enter the postsynaptic cell and potassium (K+) ions to leave the cell, making the inside of the cell more negatively charged (a change in charge that is opposite from that needed to reach threshold).

What is the difference between excretion and secretion? These are both examples of what?

Excretion is the movement of waste products from the intracellular to the extracellular environment, and secretion is the movement of manufactured molecules from the intracellular to the extracellular environment. Both are examples of exocytosis.

Name the skull bones that make up the external bones of the cranium.

External bones of the cranium: occipital bone, interparietal bones, parietal bones, temporal bones, and frontal bones

Name the skull bones that make up the external bones of the face

External bones of the face: incisive bones, nasal bones, maxillary bones, lacrimal bones, zygomatic bones, and mandible

What is the difference between internal respiration and external respiration? Which one occurs in the lungs?

External respiration occurs in the lungs. It is the exchange of oxygen and carbon dioxide between the air inhaled into the lungs and the blood flowing through the pulmonary (lung) capillaries. Internal respiration, on the other hand, occurs everywhere in the body. It is the exchange of oxygen and carbon dioxide between the blood in the capillaries all over the body (the systemic capillaries) and all of the cells and tissues of the body. Internal respiration is the real "business end" of respiration. It is the means by which the body's cells receive the oxygen they need and get rid of their waste (carbon dioxide). Without external respiration, however, there would be no oxygen in the blood for the cells to absorb and no way for the cells to dump the carbon dioxide.

Which type of vision requires more muscular effort: close-up vision or far-away vision? Why?

For close-up vision, the ciliary muscles must contract to take tension off the suspensory ligaments.

How is facilitated diffusion different from simple diffusion? What is the limiting factor in the rate of facilitated diffusion?

Facilitated diffusion requires the assistance of an integral protein or carrier protein located in the bilayer. The number of available carrier proteins limits the rate of facilitated diffusion.

Adaptive immunity is nonspecific immunity. True or false?

False

What are fibroblasts and what role do they play in connective tissue?

Fibroblasts are fixed cells. They are large, irregularly shaped cells that manufacture and secrete both the fibers and the ground substance characteristic of their particular matrix. As the cells mature and the matrix is formed, fibroblasts adopt a less active role. If additional matrix is required later, the cells can convert back to the active form.

What are the main characteristics of fibrous joints, cartilaginous joints, and synovial joints?

Fibrous joints are immovable because the bones are firmly united by fibrous tissue. Examples include joints (sutures) between most bones of the skull. Cartilaginous joints are capable of only a slight rocking movement. Examples include the intervertebral disks between the bodies of adjacent vertebrae in the spine. Synovial joints are freely movable joints such as the shoulder and stifle joints. All synovial joints share some common characteristics, including articular surfaces on the bones, articular cartilage covering the articular surfaces, and a fluid-filled joint cavity enclosed by a joint capsule. Firm connective tissue bands called ligaments may help stabilize the bones and hold the joint together.

On which bone of the pelvic limb is the calcaneal tuberosity found? What is its purpose?

Fibular tarsal bone. The fibular tarsal bone is the point of attachment for the gastrocnemius muscle and corresponds to the heel.

Describe how the lymphatic system protects the body from disease.

Filters lymph to remove potential pathogens before they can enter the circulatory system.

What is the relationship between hydrostatic pressure and filtration?

Filtration is based on a pressure gradient. Liquids may be pushed through a membrane if the pressure on one side of the membrane is greater than that on the other side. The force that pushes a liquid is called hydrostatic pressure.

Describe first, second, and third intention wound repair

First intention wound repair occurs with wounds whose edges are held in close apposition. These wounds may be superficial scratches or wounds that have been sutured or held closed with special bandages. The skin forms a primary union without the formation of granulation tissue or significant scarring. Second intention wound repair is also known as contraction and epithelialization. The edges of the wound are separated from each other, and the wound is allowed to heal without surgical closure. Granulation tissue forms to close the gap, resulting in scar formation. Third intention wound repair results when the wound is sutured at least 3 to 5 days after the injury. Granulation tissue is present in the wound by this time and helps to control infection and fill the tissue defect.

Can you list all five layers of the epidermic? What is happening in each layer?

From the innermost layer outward: 1. The stratum germinativum, also known as the stratum basale (basal layer). For the most part, this layer consists of a single row of keratinocytes, which are firmly attached to the epithelial basement membrane and actively engaged in cell division. New daughter cells move from the stratum basale to sequentially more superficial layers as they mature. In this way, they replace epithelial cells that have exfoliated at the skin's surface. Merkel cells and melanocytes are found in this layer. 2. The stratum spinosum (the prickle-cell layer). The stratum spinosum (spiny layer) is so named because when the cells of this epidermal layer are fixed for histologic exam, they contract into speculated masses that resemble sea urchins. It contains several layers of cells that are held together by desmosomes. 3. The stratum granulosum (granular layer) is the middle layer of skin. Composed of two to four layers of flattened, diamond-shaped keratinocytes, the stratum granulosum is the highest level of the epidermis where living cells can be found. The cytoplasm of these cells begins to fill with keratohyalin and lamellated granules, which in turn leads to the dramatic degeneration of the nucleus and other organelles. Without these vital parts, the cell quickly dies. The lamellar granules contain waterproofing glycolipids and are transported to the periphery of the cell, where their contents are discharged into the extracellular space. These glycolipids play an important role in waterproofing the skin and slowing water loss across the epidermis. 4. The stratum lucidum (clear layer) is found only in very thick skin. Most skin, therefore, lacks this layer. Microscopically, the stratum lucidum appears as a translucent layer composed of a few rows of flattened dead cells. In this and the outermost epidermal layer, the sticky contents of the keratogranules combine with intracellular tonofilaments to form keratin fibrils. 5. The stratum corneum (horny layer) is the outermost layer and dominates the epidermis. It constitutes up to three quarters of the total epidermal thickness and is composed of 20 to 30 rows of keratinocytes. On sagittal section, the cells are paper thin and almost two dimensional, yet when viewed from above, they appear hexagonal. These are really only the remnants of keratinocytes, because the actual cells died in the stratum granulosum. They are sometimes called horny or cornified cells, but we commonly call them dandruff and recognize them as the flakes that occasionally drop on our shoulders.

What are GABA and glycine?

Gamma-aminobutyric acid (GABA) and glycine are inhibitory neurotransmitters. GABA is found in the brain, and glycine is found in the spinal cord.

Where does gas exchange occur in the avian respiratory system?

Gas exchange occurs in the lungs between the air capillaries and the small blood capillaries that surround them.

What is the difference between glomerular filtrate and tubular filtrate?

Glomerular filtrate is the fluid that leaves the glomerular capillaries and enters the capsular space. It is similar to plasma, but without proteins. It contains waste products that need to be cleared from the body, as well as important substances that the body needs, such as sodium, potassium, calcium, magnesium, glucose, amino acids, chloride, bicarbonate, and water. Glomerular filtrate enters the proximal convoluted tubule and is termed tubular filtrate, which travels through the tubular part of the nephron. The important substances are reabsorbed from the tubular filtrate back into the body along with some urea. The body eliminates some waste products by secreting them into the tubular filtrate. Examples include hydrogen, potassium, ammonia, and some drugs.

What three groups of hormones are produced in the adrenal cortex? What are their effects?

Glucocorticoid hormones, mineralocorticoid hormones, and sex hormones. Glucocorticoids have a general hyperglycemic effect: that is, they cause the blood glucose level to rise. Mineralocorticoid hormones regulate the levels of some important electrolytes (mineral salts) in the body. The principal mineralocorticoid hormone aldosterone affects the levels of sodium, potassium, and hydrogen ions in the body. Aldosterone's target is the kidney, where it causes sodium ions to be reabsorbed from the urine back into the bloodstream in exchange for potassium and hydrogen ions. Aldosterone also affects water levels in the body, in that water accompanies sodium back into the bloodstream when sodium ions are reabsorbed. The amounts of sex hormones are very small, and their effects are usually minimal.

What are intercalated discs and why are they important to the functioning of cardiac muscle?

Intercalated discs are the attachments of the end of one cardiac muscle cell to the end of another cardiac muscle cell. They secure the cells together and transmit impulses from cell to cell, thus coordinating the contraction of large groups of cells

What is granulation tissue? Why is it important in the healing process?

Granulation tissue is a bright pink tissue that forms as macrophages work to clear debris from beneath the overlying blood clot or scab. Composed of a layer of collagen fibers manufactured by fibroblasts, granulation tissue is richly infiltrated with small permeable capillaries that have branched off existing capillaries in the deeper layers of the damaged tissue. These new tiny vessels push up into the bed of collagen fibers and provide rich supplies of nutrients and oxygen to hard-working cells such as fibroblasts, macrophages, and neutrophils. Macroscopically, the capillaries appear to be minute granules and are therefore called "granulation tissue." Granulation tissue produces bacteria-inhibiting substances, making it highly resistant to infection.

List the five types of white blood cell and indicate whether each one is a granulocyte or an agranulocyte

Granulocytes: - neutrophils - eosinophils - basophils Agranulocytes: - monocytes - lymphocytes

After ovulation has occurred, what cells in the ovary multiply to form the corpus luteum?

Granulosa cells

Other than promoting growth in young animals, what are some of other effects of GH?

Growth hormone (GH) helps regulate the metabolism of proteins, carbohydrates, and lipids in all of the body's cells. The effect of GH on protein metabolism is to encourage the anabolism, or synthesis, of proteins by body cells. The effects of GH on carbohydrate and lipid metabolism are linked. GH causes the mobilization (release) of lipids from storage in adipose (fat) tissue and their catabolism (breakdown) in body cells for energy production. At the same time, it discourages the cells from using carbohydrates, principally glucose, as energy sources. Because glucose is such an important energy source for the body's cells, a balance between GH and insulin is important to maintain homeostasis of glucose levels in the blood.

Which four hormones have hyperglycemic effects in the body? What is the only hormone that acts to lower the blood glucose level?

Growth hormone, thyroid hormone, glucocorticoid hormones, and glucagon all serve to increase the level of glucose in the blood. Insulin acts to lower the blood glucose level.

What are the two parts of the roof of the mouth?

Hard palate, soft palate

What is the difference between a Haversian canal and a Volkmann's canal?

Haversian canals are part of the haversian system of compact bone. They run lengthwise with the bone and consist of a laminated (multilayered) cylinder composed of concentric layers of ossified bone matrix arranged around a central canal. The haversian canal contains the blood, lymph, and nerve supply for the osteocytes. Volkmann's canals are channels through which blood vessels travel to supply bones. They penetrate the periosteum at right angles to the long axis of the bone and at right angles to the haversian canals. The blood vessels in the Volkmann's canals join with the blood vessels in the haversian canals to bring nutrients to the osteocytes in the haversian systems.

List three structures found in the mediastinum.

Heart, trachea, esophagus, thymus, lymph nodes, nerves

Describe the three types of T lymphocyte.

Helper T cells (TH) secrete cytokines into the surrounding tissue to improve immune response. Cytotoxic T cells (TC) attach to the antigenic cells and destroy them. Regulatory T cells (TS) inhibit helper T cell and cytotoxic T cell function by negative feedback. They also prevent B cells from transforming into plasma cells.

What is histology?

Histology is the study of the microscopic structures of tissues and oragns.

Why do hormonelike drugs generally have a high potential for undesirable side effects?

Hormonelike drugs have a high potential for undesirable side effects because the production and effects of natural hormones are so interrelated, so the therapeutic use of hormones and hormonelike drugs can produce some potent and widespread problems. Also, the amounts of hormones used therapeutically are usually very large compared with the normal physiologic hormone levels in the body; therefore, the potential for undesired side effects increases accordingly. If these drugs are not discontinued gradually, serious side effects can occur.

What is a hormone?

Hormones are chemical messages produced by endocrine glands and are secreted directly into blood vessels.

In what circumstance does a hydrogen bond commonly occur?

Hydrogen bonds are formed mostly between molecules (water) and act to stabilize a solution. Hydrogen bonding is the key to water's unique properties as a universal solvent and a medium for the life processes. Hydrogen bonds can also form between parts of the same molecule. This works to stabilize and hold the shape of large, complex molecules such as proteins and DNA.

What important function do hydrogen bonds perform in organic and inorganic chemicals?

Hydrogen bonds are primarily formed between molecules as an electrostatic attraction. Hydrogen bonding is the key to water's unique properties as a universal medium. Hydrogen bonds can also form betwee parts of the same molecule, giving it increased stability. The shape of DNA and large proteins, for example, is maintained by hydrogen bonds within the molecule.

What physiologic state of blood acts as the stimulus for erythropoiesis?

Hypoxia

What three pairs of bones make up the pelvis? What region of the pelvis does each form?

Ilium, ischium, pubis The ilium is the cranialmost bone of the pelvis. It projects upward in a dorsocranial direction and is the bone that forms the sacroiliac joint with the sacrum. The ischium is the caudalmost pelvic bone. The pubis is the smallest of the three pelvic bones. It is located medially and forms the cranial portion of the pelvic floor.

What effect does a hypotonic solution have on a cell? What passive membrane process causes this effect?

If the extracellular fluid is hypotonic, the inside of the cell contains a higher concentration of solutes than the outside of the cell. In this scenario, water would flow by osmosis into the cell and cause it to swell and possibly burst.

An animal has an area of inflammation located at the dorsal limbus of its right eye. Where is the lesion located?

If the iris is compared with the face of a clock, this lesion would be at approximately 12 o'clock, at the junction of the cornea and the sclera (white) of the eye.

If the medial rectus muscle of an animal's eye was damaged and lost its ability to contract, what would the effect be on the positioning of the affected eye? Why?

If the medial rectus muscle were unable to contract, the pull of the lateral rectus muscle would cause the eyeball to deviate (move abnormally) laterally. Also the animal would not be able to rotate that eyeball toward the midline, because this muscle originates from a small area around the optic canal and fissure and inserts on the medial side of the sclera (near the 9 o'clock position if you are standing in front of the animal).

How would an animal with a plugged nasolacrimal system appear? Why?

If the nasolacrimal system were plugged, tears would be "spilling" out of the eyes because they would have nowhere to drain.

Describe the function of each of the five immunoglobulins. When would the levels of each increase?

IgM: Acute infections IgG: Chronic infections IgA: Mucosal immunity IgE: Allergic reactions and parasitic worms IgD: Activates basophils and mast cells

What are the 8 organelles?

Mitochondria Ribosomes rough and smooth endoplasmic reticulum Golgi apparatus Lysosomes Perteasomes Peroxisomes Vaults

Explain why proteinuria occurs with renal failure.

In a normal kidney, large molecules such as protein are too big to fit through glomerular fenestrations and are retained in blood. During some types of kidney disease, the glomerulus is damaged, resulting in enlarged fenestrations and protein passing through them into urine.

How are triglycerides in adipose tissue converted into glucose for energy?

In adipose tissue lipase breaks down the triglyceride into glycerol and fatty acids that are transported to various tissues, including the liver. In the liver glycerol is converted to glucose by gluconeogenesis; in other tissues the fatty acids are oxidized to produce energy.

Where is the urethral opening located in the female?

In females, the urethra opens on the floor (ventral portion) of the vestibule, which is part of the vulva (the part that is considered the entrance to the vagina).

What is the difference between the primary growth center of a bone and a secondary growth center?

In long bones, the primary growth center is a location in the shaft (diaphysis) where bone development begins. Additional growth centers called secondary growth centers develop in the ends (epiphyses) of the bone.

Besides its urinary function, what other function does the urethra play in a male animal?

In males the urethra also has a reproductive function. The vas deferens and accessory reproductive glands enter the urethra as it passes through the pelvic canal. Here spermatozoa and seminal fluid are discharged into the urethra during ejaculation and pumped out as semen. At the beginning of ejaculation the sphincter at the neck of the urinary bladder closes, preventing semen from entering the bladder and mixing with urine.

What are the two main subcategories of the immune system?

Innate and adaptive immunity

How does ADH deficiency affect urine volume? What is the mechanism?

Insufficient ADH will increase urine volume. ADH acts on the distal convoluted tubules to promote water reabsorption into the body. If aDH is absent, water will not be reabsorbed and will be lost in urine.

Where are the proteins located in the cell membrane and what are their functions?

Integral and peripheral proteins are types of globular proteins. Some integral proteins are located within the bilayer, spanning it. These form selective passageways and pores that permit only particular substances to enter or exit the cell. Some integral proteins are membrane receptors that act as binding sites on the cell's surface. Peripheral proteins are bound to the inside and outside surfaces of the cell membrane and sometimes act as enzymes to catalyze specific chemical reactions. They may also be involved in the mechanics of changing the cell's shape. Glycoproteins, in addition to glycolipids, are the principal components of the "sugar coating" that covers the surface of some cells. This coating is called the glycocalyx.

What is the relationship between the myelin sheath and the nodes of Ranvier?

Nodes of Ranvier are small gaps in the myelin sheaths. The nodes of Ranvier and the myelin work together to enhance the conduction of stimuli.

Under what conditions is lactic acid formed in muscle cells?

Lactic acid forms when oxygen is depleted

Give specific examples of solutes in the body

Large molecules such as soluble proteins, phospholipids, cholesterol and triglycerides and also smaller electrolytes such as sulfate, hydrogen phosphate, chloride, bicarbonate, magnesium, calcium, potasium, and sodium.

According to the principle of bilateral symmetry, single structures in the body are located on or near which anatomic plane of reference?

Median plane

What are the four stages of the mitotic phase?

prophase, metaphase, anaphase, telophase

Give three examples of cells that are transient in connective tissue. Can you describe their form and functions?

Leukocytes, mast cells, and macrophages are transient cells in connective tissue. Leukocytes are relatively large and round compared with red blood cells. They can squeeze through the walls of tiny blood vessels to enter the surrounding tissue. This process is called diapedesis. Leukocytes are important members of the defensive immune system. Mast cells are oval cells easily identified by the large number of dark-staining granules stored in the cytoplasm. These granules contain histamine and heparin, potent biochemicals that, when released into the tissue, initiate an inflammatory response. Histamine increases blood flow to the area by making the capillaries leaky, and heparin prevents blood from clotting and ensures that the pathways for increased blood flow remain open. Macrophages are massive, irregularly shaped phagocytizing scavengers that may be either fixed or transient in connective tissue. They engulf microbes, dead cells, and debris that are subsequently digested in the macrophage's lysosomes. Mobile macrophages are drawn to sites of infection or inflammation, where they move aggressively through the affected area to engulf microinvaders. In this way they are an important part of the immune system and help tissues fight infection.

Where is stratified squamous epithelium found? (1 place)

Lining the mouth, esophagus, vagina, rectum

What is the function of lipids in the body?

Lipids are used in the body for energy and are stored in fat for future energy needs. Lipids also serve as chemical messengers in the form of some hormones.

What is the function of a lymph heart?

Lymph hearts are areas of lymph vessels that contain smooth muscle. Their purpose is to actively pump lymph through the vasculature. The presence of the large lymph vessels in association with blood vessels results in relatively frequent lymph contamination of samples during venipuncture.

What is the function of a lymph node?

Lymph nodes trap antigens and other foreign material carried in lymph.

Where is lymph formed?

Lymph starts out as excess interstitial tissue fluid picked up by small lymph capillaries. The excess tissue fluid accumulates when more fluid leaves blood capilaries than reenters them.

Where does gas exchange take place in the reptilian lung?

Macroscopically, the pulmonary tissue of amphibians and reptiles has a honeycomb appearance. The openings of the honeycomb terminate in gas exchange structures are called faveoli. Unlike mammalian alveoli, the faveoli are fixed structures and do not expand or contract. The faveoli are surrounded by capillary beds, where the blood takes up oxygen and releases carbon dioxide. Gas exchange can also occur across the mucous membranes of the buccal cavity and pharynx. Many aquatic chelonians are also capable of exchanging gases across the mucous membranes of the pharynx and cloaca.

Why don't the mammary glands of male animals usually develop or secrete milk?

Males' mammary glands don't develop and secrete milk because they do not have the balance of hormones required.

What is the difference between a symport and an antiport system?

Many active transport systems move more than one substance at a time. If all the substances are moved in the same direction, the system is called a symport system. However, if some substances are moved in one direction and others moved in the opposite direction, the system is called an antiport system.

What is the matrix of bone made of? What makes it so hard?

Matrix is the intercellular substance in which bone cells are embedded. It is hard because calcium and phosphate crystals are deposited in it.

What is the purpose of stratified squamous epithelium that lines much of the GI tract?

protection

What are membrane receptors and ligands, and what role do they play in the health of a cell? How does obesity affect cell membrane receptors for insulin?

Membrane receptors are integral proteins and glycoproteins that act as binding sites on the cell surface. Some of them play a vital role in cell-to-cell recognition, a process called contact signaling. This particularly important during cell-mediated immune responses and helps bacteria and viruses find preferred "target" cells. Membrane receptors are also involved in a process called chemical signaling. Hormones, neurotransmitters, and other chemical messengers called ligands bind to specific binding sites on cell surfaces. Once bound to the cell membrane, ligands can bring about a change in the cell's activity. Some ligands act as enzymes to activate or inactivate a particular cellular activity.

Describe merocrine, apocrine, and holocrine glands. How do they differ from one another?

Merocrine glands: The majority of glands package their secretions into granular units and release them via exocytosis as they are manufactured. In merocrine glands, the secretory cells remain undamaged during secretion. Secretion in apocrine glands involves the loss of the apex of the secretory cell. Apocrine glands: The secretory cells in apocrine glands do not release their granules as they are manufactured. Instead they store the granules until the apex of the cell is full, at which point the cell pinches in two and the top part (the apex) is released into the duct system. Later, the cell repairs the damage and repeats the process. Holocrine glands: Holocrine glands also store granules in the secretory cells until they are needed. However, in holocrine glands the entire secretory cell is destroyed in the act of releasing its secretory product. The subsequent degeneration of the cell allows the release of the granules.

What is the term for mRNA formation?

Messenger RNA (mRNA) formation is known as transcription, which occurs in the nucleus.

Why do some epithelial cells have cilia and microvilli? What role do they play? Where are the cells with these specialized surfaces found in the body?

Microvilli increase the surface area of cells and allow more absorption and secretion. They are found on epithelial cells in the intestines and urinary tract. Cilia are found on the free surfaces of cells, usually in the respiratory and urogenital tracts. Ciliary movement occurs in coordinated "beats" that enable the efficient transport of material. In the trachea, cilia help propel mucus and debris up and away from the lungs toward the mouth. In the uterine tube, the beating motion of cilia encourages newly released ova into the oviduct, or infundibulum.

Name the three subatomic particles.

protons, neutrons, electrons

How does cell division by meiosis differ from cell division by mitosis?

Most of the body's cells divide through a process called mitosis. When a cell divides by mitosis, each of its chromosomes first produces a duplicate copy of itself. When the two daughter cells pull apart, half the chromosomes go to one cell and half go to the other. Each of them ends up with an identical full diploid set of chromosomes. The two daughter cells have exactly the same genetic makeup as each other and as the parent cell. This ensures that the genetic information in all of the body's cells (except for the reproductive cells) stays exactly the same. Reproductive cells are produced by meiosis, in which the chromosomes do not produce duplicate copies of themselves before the daughter cells pull apart. Half of the total chromosomes (one from each diploid chromosome pair), including one sex chromosome, go to each daughter cell. Which chromosomes go to which daughter cell is entirely random. The chromosomes merely pull apart into their new cells. In this way the genetic material of the reproductive cells gets shuffled, resulting in genetically unique offspring.

By which mechanism of bone formation do most bones in the animal body develop before birth, and how does the process take place?

Most of the bones in the body develop by the endochondral method, in which the body first creates a cartilage template that is subsequently replaced by bone. Most bones start out as rods of cartilage in the developing fetus. These cartilage rods are prototypes of the bones that will eventually replace them.

Which are afferent nerve fibers: motor nerve fibers or sensory nerve fibers? Which are efferent?

Motor nerves are efferent. Sensory nerves are afferent.

Where are mucous membranes found? What functions do they perform?

Mucous membranes, or mucosae, are always found lining the organs with connections to the outside environment. These organs are part of the digestive, respiratory, urinary, and reproductive tracts and include the mouth, esophagus, stomach, intestines, colon, nasal passages, trachea, bladder, uterus, and others. With the exception of the mucosae of the urinary tract, mucosae in general can produce large quantities of protective and lubricating mucus. Goblet cells or multicellular glands may be found throughout the tissue. These structures are responsible for the production and secretion of mucus, which consists primarily of water, electrolytes, and a protein called mucin. Mucus is slippery and therefore can decrease friction and assist with the passage of food or waste. Because of its rich supply of antibodies and its viscous consistency, mucus is also helpful in the entrapment and disposal of invading pathogens and foreign particles. This is particularly apparent in the nasal passages, where microorganisms and debris are inhaled and trapped by mucus. Some mucosae can also absorb as well as secrete. For example, the epithelial layer in the intestine is specially designed for rapid and efficient transfer of nutrient molecules from the intestinal lumen to the underlying connective tissue and its blood supply. The mucosa therefore plays an important role in monitoring and controlling what enters the body, and mucous membranes form an important barrier between the outside environment and the delicate inner workings of the body. The secretory and absorptive qualities of mucosae make them particularly well suited for this role.

How are multicellular exocrine glands constructed?

Multicellular exocrine glands are made up of two distinct components, a secretory unit in which secretions are produced by secretory cells and a duct that carries the secretion to the deposition site. In most glands the secretory unit is surrounded by connective tissue rich in blood vessels and nerve fibers. It not only nourishes the secretory unit but also provides structural support and may extend into the gland to form distinct lobes. In some exocrine glands the secretory unit is surrounded by contractile cells called myoepithelial cells that assist with the discharge of secretions into the glandular duct.

What types of cells are phagocytic?

Neutrophils, eosinophils, monocytes, tissue macrophages. All white blood cells except lymphocytes and basophils are capable of phagocytosis.

What does the rough endoplasmic reticulum do in the cell?

Newly manufactured molecules of protein are moved internally into passageways in the RER known as cisternae ("reservoirs"). Here the protein are modified before being moved on to the Golgi apparatus for further modiciation and packaging. The membrane of the RER is an extension of the outer nuclear membrane, so that RER is often found near the nucleus.

With which branch of the autonomic nervous system are muscarinic and nicotinic receptors associated?

Nicotinic acetylcholine receptors are found primarily on the postganglionic neurons of both the sympathetic and parasympathetic nervous systems. Muscarinic cholinergic receptors are found on the target organs and tissues supplied by the postganglionic neuron of the parasympathetic nervous system

What element is found in all proteins that is not found in carbohydrates or lipids?

Nitrogen

Do birds have a diaphragm?

No

An animal can intentionally blink its eyelids. Can it intentionally cover its eye with its third eyelid? Why or why not?

No muscles attach to the third eyelid Its movements are entirely passive.

Are only organic compounds necessary for life?

No. Both organic and inorganic compounds are necessary for life on earth.

Is interphase a time when the cell is resting? Why or why not?

No. Interphase is a period of intense metabolic activity in the cell. Before each cell can divide, a perfect copy of DNA must be created to pass on to the daughter cells. This replication of DNA occurs during interphase. In addition, all of the enzymes and other proteins needed to drive cell division must be created during interphase.

Does urine production stop when the urinary bladder is full?

No. The kidneys continue to produce urine regardless of the volume of urine present in the bladder.

What is nociception and what roles do transduction, transmission, modulation, and perception play in it?

Nociception is the process of experiencing pain. Transduction is the conversion of the painful stimulus to a nerve impulse that occurs at the sensory nerve ending. Transmission of the nerve impulse up the sensory nerve fibers to the spinal cord is the next step. Modulation (changing) of the sensory nerve impulses can occur in the spinal cord, and this can significantly influence the information the brain receives, particularly in cases of chronic and/or severe pain. This modulation process can amplify (make more severe) or suppress (make less severe) sensory impulses through synapses between neurons in the dorsal horns of the spinal cord. Finally, perception of the painful impulses by several areas of the brain occurs. Conscious perception occurs in the cerebral cortex, but other areas of the brain are also involved. These include areas involved with the autonomic nervous system (fight or flight), fear and anxiety, memory, arousal, and behavior and emotion.

What are the 12 cranial nerves? Which nerves are motor, which are sensory, and which are both?

Olfactory: sensory Optic: sensory Oculomotor: motor Trochlear: motor Trigeminal: both sensory and motor Abducent: motor Facial: both sensory and motor Vestibulocochlear: sensory Glossopharyngeal: both sensory and motor Vagus: both sensory and motor Accessory: motor Hypoglossal: motor

Which chamber is known as the many plies?

Omasum

The connecting peritoneum that links the stomach to the abdominal wall is the ____.

Omentum

What stimulates the continued release of prolactin during lactation?

Once lactation begins, prolactin production and release by the anterior pituitary gland continue as long as the teat or nipple continues to be stimulated by nursing or milking.

What is the difference between organic and inorganic compounds?

Organic compounds are molecules that contain hydrocarbon chains and groups (hydrogen and carbon) and usually are covalently bonded. Inorganic molecules, on the other hand, do not contain hydrocarbon chains and groups and are often ionically bonded.

What is the relationship between solutes and osmolality?

Osmolality is a measurement of the concentration of solute in fluid. As the concentration of solute increases (or decreases), so too does the osmolality. In other words, fluids that have a high concentration of solutes have a high osmolality.

What is the difference between ossicles and otoliths?

Ossicles are small bones in the middle ear that conduct sound waves from the tympanic membrane to the oval window of the cochlea. Otoliths are tiny calcium carbonate stones in the vestibule that respond to gravity to provide information about the position of the head.

What are otoliths and why are they important to the equilibrium sense?

Otoliths are tiny crystals of calcium carbonate in a gelatinous matrix that covers hair cells and supporting cells of the macula. The hair cells are similar to the hair cells of the organ of Corti in the cochlea. Gravity causes the otoliths and the gelatinous matrix to put constant pressure on the hairs as long as the head stays still. Movement of the head bends the sensory hairs, which generate nerve impulses that give the brain information about the position and linear movement of the head. Otoliths are important to the sense of equilibrium because information sensed by the vestibule (which contains the otoliths) regarding linear motion and head position is integrated with information about rotary motion of the head gained by the semicircular canals so that the brain can form a picture of what is happening to the animal's head, and by extension, to its body as a whole. Together, the vestibule and semicircular canals provide the total picture of equilibrium to the brain.

What causes pigmentation of skin?

Pigmentation is caused by the presence or absence of melanin granules in the armlike extensions of the melanocytes. Macroscopically, no pigmentation is apparent if the granules are concentrated around the nucleus in the cell body of the melanocyte. As the granules move into the cellular arms and into the surrounding tissue, however, pigmentation becomes apparent. The more granules that exist in the arms of the melanocyte and surrounding tissue, the darker the pigmentation. The dispersion of granules is controlled by the release of melanocyte-stimulating hormone, which, in turn, is controlled by the intermediate lobe of the hypophysis. The melanosomes are transported to the tips of the cellular projections, where they are released into the intracellular space and ultimately absorbed by keratinocytes, which arrange the melanin on the side of the cell with the greatest amount of sun exposure. In this way, pigment acts to protect cells from the damaging effects of ultraviolet rays.

How does lymph differ from plasma?

Plasma is the fluid portion of whole blood and carries substances such as nutrients, oxygen, and hormones to bathe the cells and tissues Lymph comes from plasma but is different from plasma in that it is made up of more water, sugar, and electrolytes and less of the larger proteins found in plasma.

What is the difference between plasma and serum?

Plasma is the liquid portion of whole blood or a blood sample when the sample has not been allowed to clot. Serum is the liquid portion of a blood sample after the sample has been allowed to clot, removing the clotting elements. Plasma is prepared by centrifuging anticoagulated blood. Serum is prepared by allowing blood to clot.

Why are platelets not considered complete cells?

Platelets do not have nuclei. They are not complete cells but are pieces of cytoplasm that bud off of giant, multinucleated bone marrow cells called megakaryocytes and are sent into circulation.

Explain the difference between prerenal uremia and postrenal uremia.

Prerenal uremia is associated with decreased blood flow to the kidneys and may be caused by conditions such as dehydration, congestive heart failure, or shock if these conditions are left untreated. In these cases the kidneys are functioning normally but not enough blood is reaching them, so waste materials can't be adequately removed. Postrenal uremia is usually associated with an obstruction that prevents urine from being expelled from the body. Tumors, blood clots, or uroliths (stones) can cause the obstruction. Eventually urine backs up into the kidney pelvis and then into the nephrons, increasing pressure in the nephrons and causing nephron damage.

What is the difference between a prokaryote and a eukaryote?

Prokaryotes do not contain nuclei. Eukaryotic cells have a distinct nucleus in which the DNA has combined with protein to form chromosomes. These, in turn, are surrounded by a protective nuclear envelope.

Why is the proprioceptive sense so important to the maintenance of balance and an upright posture?

Proprioception allows animals to perform such basic functions as procuring food and escaping danger so they can survive. Maintenance of balance and an upright posture is essential to these activities.

What are the pros and cons of fever?

Pros: - increased rate of phagocytosis - slowed bacterial growth - potential killing of the pathogen Cons: - denaturing of the protein - injury to body tissues and cells

Why are prostaglandins referred to as tissue hormones?

Prostaglandins are sometimes called tissue hormones because they travel only a short distance from where they are produced as opposed to hormones, whose effects occur at a longer distance from where they are produced.

What do proteasomes do in the cell?

Proteasomes are minute structures that consume individual, often misfolded proteins and digest them. They are found throughout the cytosol.

What is the main function of the immune system?

Protect the body from foreign invaders and prevent disease.

What is the difference between a saturated and an unsaturated fat? Why is this difference important nutritionally?

Saturated fatty acids have single bonds between the carbon atoms and can accommodate the greatest number of hydrogen atoms attached to the chain of carbon atoms. Saturated fatty acids tend to have long chains and are primarily found in meat and dairy foods such as milk, cream, cheese, lard, and butter. Coconuts are one of the few plant sources of saturated fats. Alternatively, unsaturated fatty acids have one or more double bonds between the carbon atoms and can accommodate fewer hydrogen atoms. These are found in seeds, nuts, and most vegetables.

What structures are derivatives of a bird's skin and what are they made of?

Scales, feathers, and the outer sheath of beaks and claws are made of keratin, which is produced by epithelial cells.

What are secondary functions of the respiratory system?

Secondary functions include voice production, body temperature regulation, acid-base balance regulation, and the sense of smell.

How are serous and mucous secretions different?

Serous secretions are watery and contain a high concentration of enzymes, whereas mucous secretions are thick, viscous, and composed of glycoproteins. Secretory cells that manufacture both types of secretions are common in the digestive and respiratory tracts. Mixed exocrine glands contain both mucous and serous components.

How is sex determined in reptiles that do not possess sex chromosomes?

Sex in reptiles is determined by either genotype or the temperature at which eggs are incubated. Sex chromosomes are not present in species such as crocodilians, chelonians, tuataras, and some lizards; therefore, egg incubation temperature determines the sex of the hatchling. In general, higher incubation temperatures produce males and lower temperatures produce females in crocodilians and lizards. The opposite occurs in chelonians. In nature there is typically a temperature range within the nest that allows the production of a mixed clutch of male and female hatchlings. Reptiles that possess sex chromosomes differ from mammals in that the females are the heterozygous sex (ZW) and males are homozygous (ZZ).

Epithelial tissue is characterized as simple, stratified, or pseudostratified. What does this mean?

Simple - single layer of epithelial cells Stratified - more than one layer of epithelial cells Pseudostratified columnar epithelium is not truly stratified, though it appears to be since the nuclei are found at different levels

What are the main differences in the structures and functions of skeletal muscle, cardiac muscle, and smooth muscle?

Skeletal muscle is composed of long, multinucleated cells that are under conscious control. They are striated when viewed microscopically. They move the bones that move the animal's body. Cardiac muscle is found only in the heart. It is made up of striated muscle cells that are not under conscious control. The cells have only one nucleus each. Intercalated discs join cardiac muscle cells end to end. Smooth muscle cells are nonstriated and have a single nucleus. They are not under conscious control. They are found in the walls of internal organs and locations, such as the eye, where delicate movements are necessary.

Why are cells not the size of watermelons?

Smaller cells have smaller nutritional requirements than large cells but have a propertionately larger surface through which they can absorb the substances they need. Thus smaller cells are able to complete their metabolic functions more rapidly and efficiently than large cells. If cells were the size of watermelons, they would not be able to take in nutirents fast enough to feed themselves and they would die. A second limiting factor in cell size is related to the governing capability of the nucleus. A single nucleus can control the metabolic activity of a small cell better than it could a large one. Also, the more active a cell is, the greater its metabolic needs.Cells that are larger or are more active (such as cardiac and skeletal muscle cells) have two or more nuclei.

What does smooth endoplasmic reticulum in the cell do?

Smooth ER, which is connected to rough ER, is active in the synthesis and storage of lipids, particularly phospholipids and steroids, and is therefore seen in large quantities in gland cells. In liver cells smooth ER may also function to eliminate drugs and break down glycogen into glucose.

Which reptiles do not have external ear openings?

Snakes do not have external ear openings. Salamanders and caecilians do not have tympanic membranes.

What are some examples of electrolytes?

Sodium (Na) Potassium (K) Calcium (C)

What are the principal ions involved in maintaining a cell's resting membrane potential?

Sodium and potassium

Is there normally a higher concentration of sodium inside or outside the cell? Where is there a higher concentration of potassium?

Sodium is 10 to 20 times higher outside the cell than it is inside. Potassium is 10 to 20 times higher inside the cell than outside.

What are the differences between an autonomic reflex and a somatic reflex?

Somatic reflexes involve contraction of skeletal muscles. Autonomic reflexes regulate smooth muscle, cardiac muscle, and endocrine glands.

How does specific immunity differ from nonspecific immunity?

Specific immunity responds to particular antigens in particular ways, whereas nonspecific immunity responds to all antigens and attacks them in the same way.

What are the main components of the spermatic cord?

Spermatic cords are tubelike connective tissue structures that contain blood vessels, nerves, lymphatic vessels, and the vas deferens. Surrounding the artery is a structure called the pampiniform plexus, which is an intricate meshwork of tiny veins derived from the testicular veins.

What sit the function of Kupffer cells?

they are hepatic macrophages that engulf foreign substances

How does spermatogenesis differ from oogenesis? Why are the basic processes so different?

Spermatozoa are produced continuously and in very large numbers in an effort to ensure that one spermatozoon will successfully reach and fertilize the ovum when breeding occurs, so the process of spermatogenesis is designed to produce huge numbers of spermatozoa. Alternatively, ova are not produced continuously like spermatozoa. At or soon after birth, a female has a fixed number of primary oocytes (the precursor cell to ova) formed in her ovaries. That will be the total number available in her lifetime. They remain in a quiet, immature state until the ovarian cycles begin. Each ovarian cycle produces one or more mature ova, depending on the species. Because spermatozoa come to the ovum to fertilize it, large numbers of ova are not needed. Therefore, the process of oogenesis is designed to produce small numbers of ova at a time.

What structures do spermatozoa pass through from their site of production to their eventual deposition in the female reproductive tract?

Spermatozoa pass through the seminiferous tubules, rete testis, efferent ducts, epididymis, vas deferens (including the ampulla in some species), and urethra

What organs are involved in immunity?

Spleen, lymph nodes, thymus, GALT, bone marrow

What are the three basic shapes of epithelial cells?

Squamous (flattened like pancakes) Cuboidal (cube-like shapes) Columnar (column-like shapes)

What is the difference between a sternal rib, an asternal rib, and a floating rib?

Sternal ribs join the sternum and make up the cranial part of the thorax. The ribs that join the adjacent costal cartilage are called asternal ribs and make up the caudal part of the thorax. The cartilage of the last rib or two on each side may not join anything at all and just end in the muscles of the thoracic wall. These nonattached ribs are called floating ribs.

How is the larynx involved in the straining process that aids functions such as defecation?

Straining begins with the animal holding the glottis closed while applying pressure to the thorax with the breathing muscles. This stabilizes the thorax and allows the abdominal muscles to effectively compress the abdominal organs when they contract. Without the closed glottis, contraction of the abdominal muscles merely forces air out of the lungs (exhalation).

How do the physical characteristics of the alveoli and the capillaries that surround them facilitate the exchange of gases between the air in the alveoli and the blood in the capillaries?

Structurally, the alveoli are tiny, thin-walled sacs that are surrounded by networks of capillaries. The wall of each alveolus is composed of the thinnest epithelium in the body—simple squamous epithelium. The capillaries that surround the alveoli are also composed of simple squamous epithelium. The main physical barriers between the air in the alveoli and the blood in the capillaries are the very thin epithelium of the alveolus and the adjacent, equally thin epithelium of the capillaries. These two thin layers allow oxygen and carbon dioxide to freely diffuse back and forth between the air and the blood. Each alveolus is lined with a thin layer of fluid that contains a substance called surfactant. Surfactant helps reduce the surface tension (the attraction of water molecules to each other) of the fluid. This prevents the alveoli from collapsing as air moves in and out during breathing.

What is the chemical composition of a struvite crystal?

Struvite crystals are composed of magnesium, ammonium, and phosphate.

What are two nerve plexuses that make up the intrinsic enteric nervous system?

Submucosal plexus (Meissner's plexus) and the myenteric plexus (Auerbach's plexus)

Describe what happens to a zygote between fertilization and implantation.

The fertilized ovum is called a zygote. Immediately after fertilization, the nucleus of the spermatozoon is called the male pronucleus and the nucleus of the ovum is called the female pronucleus. Each carries the haploid chromosome number. The male and female pronuclei quickly join together to restore the diploid chromosome number and determine the unique genetic makeup of the offspring. As soon as the two pronuclei join to form a single nucleus, the zygote begins to divide rapidly by the normal process of mitosis. This rapid division is called cleavage. The single cell divides into 2 cells, which quickly divide into 4, then 8, then 16, and so on. Cleavage occurs so rapidly that the cells of the zygote do not have time to grow between divisions. The number of cells making up the zygote is increasing dramatically, but its overall size is still about the same as the original ovum, even after several days. While cleavage is taking place, the zygote slowly moves down the oviduct toward the uterus. Delicate, muscular contractions and the movements of cilia are gently propelling it along. After a few days the zygote is a solid mass of cells that looks like a tiny raspberry; this is known as the morula stage. The cells of the morula continue to divide and gradually form a hollow cavity in the center. By the time it reaches the uterus a few days later, it is formed into a hollow ball of cells with a bump on one side that eventually forms into the embryo. It is now called a blastocyst, and it is ready to implant itself in the lining of the uterus

Describe the series of events that scientists believe led to the formation of the first cells on earth

The first cells are thought to have evolved in the massive oceans of our primitive Earth about 3 billion years ago. Jolted by the fierce electrical energy from frequent lightning storms and by the intense, unabated radiation from the sun, the three molecules (methane gas, water, ammonia) that made up the primitive atmosphere were forced to collide and splint apart. The first organic molecules, similar to amino acids, are thought to have formed in this tempestuous environment. Clustering into heavy droplets, these molecules are believed to have been washed by driving rains from the atmosphere into the warm, shallow seas below. There, proteins, lipids, and carbohydrates evolved and arranged themselves over time into sophisticated, organized structures - the first cells.

Describe the attachment of the skull to the vertebral column. What does this type of attachment provide?

The first cervical vertebra, the atlas, contains a single condyle (ball and socket type of structure) for attachment of the skull. This allows a greater range of head movement compared with mammals, which have two condyles attaching the skull to the vertebral column.

What are the names of the first two cervical vertebrae and what are their distinguishing characteristics

The first cervical vertebra, the atlas, holds up the head. It has two large winglike transverse processes (called the wings of the atlas) that can be palpated just behind the skulls of most animals. The atlas is unique in that it has no vertebral body. It consists only of the bony ring the spinal cord passes through and two wings sticking out laterally. The second cervical vertebra, the axis, has a large bladelike spinous process that projects upward dorsally and a peglike dens that fits into the caudal end of the atlas to help form the atlantoaxial joint.

What is the difference between the first and second lines of defense against invading pathogens?

The first line of defense is composed of external barriers (skin, mucous membranes, secretions). The second line of defense is internal and activated only when the first line of defense fails.

Which of the three phases of swallowing is under conscious control?

The first phase that takes food to the pharynx

what is the first stage of cellular catabolism called? Is energy produced or consumed?

The first stage of catabolism is called hydrolysis. Energy is produced.

Describe the three stages of labor.

The first stage of labor consists of uterine contractions. The muscle of the uterus (the myometrium) contracts, pressing the membrane-covered fetus down against the cervix and causing the cervix to gradually dilate. Externally, the dam appears restless and uncomfortable. She may repeatedly lie down and get up and may urinate frequently. Some species, such as the dog and pig, may attempt to build a nest into which they will deliver their young. The second stage of labor consists of the delivery of the newborn. This is accomplished by a combination of strong uterine and abdominal muscle contractions. The dam typically lies down and strains in a rhythmic pattern of contractions that gradually become stronger and closer together. The amniotic and allantoic sacs of the placenta (afterbirth) usually rupture before the actual delivery of the newborn. The third stage of labor is the delivery of the placenta. The placenta separates from the wall of the uterus and is expelled by weaker uterine contractions. The dam often eats the placenta or placentas. In multiparous species, such as the dog, cat, and pig, the second and third stages of parturition intermix with one another. Typically newborns and placentas are delivered alternately; that is, after a newborn is delivered, its placenta is usually expelled before the next newborn is delivered.

How do basic communication and control functions differ between the nervous system and the endocrine system?

The nervous system's chemical messengers, neurotransmitters, are contained in nerve endings. They are released across the small synaptic space when nerve impulses reach the nerve ending. This allows the nervous system to react quickly to changes, but neurons (nerve cells) cannot sustain individual activities for long periods of time. The endocrine system's chemical messengers, hormones, are released into the bloodstream, where they travel to their target cells. This causes the endocrine system to react more slowly to changes, but it can sustain individual activities for long periods of time.

What is the difference between the absolute and the relative refractory periods?

The neuron is said to be in a refractory period because it is refractory or insensitive to new stimuli until it recovers from the previous nerve impulse. During this period, the neuron cannot respond to cause a second depolarization. The absolute refractory period is the period of sodium influx and early potassium outflow when no stimulus of any intensity can cause the cell to depolarize again. The cell absolutely cannot respond. The relative refractory period is the period toward the end of repolarization when it may be possible to stimulate depolarization if a stimulus is very large relative to a "normal" stimulus.

What is the functional relationship between a neurotransmitter and a receptor? Will any neurotransmitter stimulate any receptor?

The neurotransmitter molecules released by the synaptic knob bind with receptors and trigger a change in the postsynaptic cell. However, the postsynaptic membrane receptors are very specific about which neurotransmitters they will bind. If the neurotransmitter and receptor are not matched, they will not bind to each other, and no change will be triggered in the postsynaptic cell. Thus synaptic transmission is only effective if receptors to the neurotransmitter exist on the postsynaptic cell's membrane.

Describe a nuclear envelope. How is it different from the cell membrane?

The nuclear envelope is composed of a lipid bilayer. The outer layer of the nuclear envelope is continuous with the endoplasmic reticulum. More than 10% of the nuclear surface consists of nuclear pore complexes - places where the two layers of the nuclear envelope have fused to form a channel. Although the nuclear envelope is similar in structure and composition to the cell membrane, passage of molecules into the nucleus is less selective because the nuclear pore complexes are relatively large (0.1nm in diameter).

What is the significance of the nucleus? What happens in that region of the nucleus?

The nucleoli are regions in the nucleoplasm where there are accumulations of ribosomal RNA (rRNA) and collections of ribosomal subunits. Each ribosome is composed of two different subunits. These ribosomal subunits are exported separately from the nucleus and assembled in the cytoplasm to form functional ribosomes. In addition, nucleoli contain the DNA needed to synthesize rRNA.

What are the nucleotides found in DNA? RNA?

The nucleotides found in DNA are adenine (A), cytosine (C), guanine (G), and thymine (T). The nucleotides found in RNA are adenine (A), cytosine (C), guanine (G), and uracil (U).

Why is the nucleus considered the "CEO of operations"?

The nucleus is considered the "CEO of operations" because its primary function is to house the interited instructions for making all of the protein needed by the organism. The type of enzyme produced by the cell determines its metabolic activities and function. the hereditary information (DNA) is duplicated prior to cell division so that each daughter cell is given an identical copy of the instructions to make all of the types of protein needed by the cell.

How does hair form and grow?

The part of hair visible above the skin is called the shaft, and the portion buried within the skin is called the root. A web of sensory nerve endings called the root hair plexus envelops the root, making it an important touch receptor when the hair is bent. Hair is anchored by the hair follicle. The follicle is an invagination of the epidermis that extends from the skin surface to the dermis or, occasionally, the hypodermis. The deepest part of the hair follicle expands to form a hair bulb. At the base of the bulb is a mound of dermal cells called the papilla. The papilla is covered with rapidly dividing epithelial cells called the matrix. These cells are nourished by blood flow from vessels in the underlying papilla, which stimulates much cell division and growth. As cells divide, older cells are pushed upward into the follicle tunnel away from the papilla. These cells become keratinized, and as they lose contact with the nutrition provided by the papilla, they die and become part of the developing hair. In this way, hair is constructed from dead epithelial cells. The wall of a hair follicle is composed of three layers: an internal epithelial root sheath, an outer epithelial root sheath, and a dermal or connective tissue root sheath. Animals with fur often have compound follicles in which multiple hair strands emerge from a single epidermal orifice, or pore, although each strand has its own follicle and bulb. As many as 15 hairs may be associated with one pore. Usually in compound follicles a single long primary hair (also known as a guard hair or cover hair) is surrounded by shorter secondary hairs called satellite hairs. In dogs, usually three compound follicles are grouped together to emerge from the same epidermal fold. Hair is formed in three concentric layers. The innermost layer (and central core) is called the medulla. It is composed of two to three layers of loosely arranged cells that are separated by spaces filled with liquid or air. The cells themselves contain flexible, soft keratin similar to that found in the stratum corneum of the epidermis. Surrounding the medulla is the cortex. Unlike the flexible medulla, the cortex is stiff and rigid because it is composed of hard keratin and is the thickest of the three layers. A single layer of cells arising from the edge of the papilla form the hair surface, the cuticle, which is also composed of hard keratin. The cells of the cuticle are layered like shingles on a roof, which prevents the hairs from sticking together and forming mats. In some animals such as sheep, however, the edges of the cells in the cuticle are raised, enabling them to grab onto the cuticle cells from other hair strands.

What is enterohepatic circulation?

The pathway that bile salts take from the liver to the intestines, to the portal vein, and back to the liver. This circulation bypasses systemic circulation

How can you use the hematocrit to evaluate a patient for anemia?

The percentage of red blood cells will be decreased in anemia, which occurs when the animal's red blood cell count is low or when the red blood cells are smaller than normal.

How do the pharynx and larynx work together to keep swallowed material from entering the trachea? What role does the epiglottis play in the process?

The pharynx and larynx work together to prevent swallowing from interfering with breathing, and vice versa. The seemingly simple act of swallowing actually involves a complex series of actions that stops the process of breathing, covers the opening into the larynx, moves the material to be swallowed to the rear of the pharynx, opens the esophagus, and moves the material into it. Once swallowing is complete, the opening of the larynx is uncovered and breathing resumes. The epiglottis is the structure that temporarily covers the opening to the larynx so that food can pass over it and into the rear of the pharynx and esophagus.

Why is the pituitary gland referred to as the master endocrine gland?

The pituitary gland is often called the master endocrine gland because many of its hormones direct the activity of other endocrine glands.

Describe the relationship between the fetus and the amniotic and allantoic sacs of the placenta.

The placenta consists of layers of soft membranes that form two fluid-filled sacs around the developing fetus. The layer immediately around the fetus is called the amnion. It forms a sac around the fetus called the amniotic sac. The fetus floats in amniotic fluid inside this sac. Surrounding the amniotic sac is another layer called the allantois, which forms the fluid-filled allantoic sac. The outside of the allantoic sac is covered by the chorion, which attaches to the uterine lining. The chorion is linked to the fetus by the umbilical cord.

Why is the placenta so important to a successful pregnancy?

The placenta is a life-support system for the developing fetus. The fetus receives all the nutrients and other substances it needs to grow and develop from its mother through the placenta. It also depends on her to dispose of the waste products it produces. Fortunately, the placenta grows right along with the fetus and meets its needs.

Where is the pleura found? Where is the peritoneum found?

The pleura is found in the thoracic cavity, and the peritoneum is in the abdominal cavity.

What is the genetic basis of cellular differentiation?

The position of genes in chromosomes determines the genetic basis of cellular differentiation. Some genes may be located on a region of the chromosome that is available for transcription, whereas other genes may be located inside the molecule and cannot be reached by transcription molecules. We say that one gene is "turned on" while the other gene is "turned off." Genes can be turned off permanently or temporarily. Chromosomes are dynamic in their ability to twist, so that a gene that was once inaccessible on the inside can be moved to the outside of the molecule for use. Differentiation involves the temporary or permanent inhibition of genes that may be active in other cells.

During repolarization, what ion channels open and what ion moves? Where does it move?

The potassium channels open and potassium moves out of the cell.

What is the difference between the preload and the afterload in reference to the stroke volume?

The preload is the amount of blood the ventricle receives from the atrium. The afterload is the amount of physical resistance presented by the aorta.

What does systolic blood pressure measure?

The pressure produced in an artery by the blood ejected from the left ventricle during systole.

Why is negative intrathoracic pressure important to breathing? What happens if it is lost?

The pressure within the thorax is negative with respect to atmospheric pressure and creates a partial vacuum within the thorax. That partial vacuum pulls the lungs tightly out against the thoracic wall. The soft, flexible nature of the lungs allows them to conform closely to the shape of the inside of the thoracic wall. Pleural fluid between the lungs and the thoracic wall provides lubrication. As the thoracic wall goes, so go the lungs. The lungs follow passively as movements of the thoracic wall and diaphragm alternately enlarge and reduce the volume of the thorax. The whole system functions like a bellows as it pulls air into the lungs (inspiration) and blows it back out (expiration). Without this negative pressure, the lungs would collapse and not be able to fill. In addition, blood return to the heart would be decreased.

What are the two parts of the cardiovascular system? Which part carries blood to and from the left rear leg of a pony?

The pulmonary circulation and the systemic circulation. The systemic circulation.

In a pregnant ewe, which are the only two veins that are carrying oxygenated blood?

The pulmonary vein that carries oxygenated blood to the left atrium from the pulmonary circulation and the umbilical vein that carries oxygenated blood from the mother to the fetus.

How would an animal probably feel if they had a middle ear infection that caused the opening of the Eustachian tube to swell closed?

The purpose of the eustachian tube is to equalize the air pressure on the two sides of the tympanic membrane. With an infection that closes it off, this could not happen and would cause pain as the membrane bulges in and out, because the tympanic membrane has many pain receptors.

What is the purpose of the renal portal system?

The purpose of the renal portal system is to conserve water. It allows the reptile to discontinue blood flow to the glomeruli and decrease urine production during times of dehydration while maintaining blood flow to the renal tubules.

Name one hormone whose release is regulated by the kidney, one hormone that directly affects kidney function, and one hormone produced by the kidney.

The release of antidiuretic hormone is regulated by the kidneys. Aldosterone directly affects kidney function. Erythropoietin is produced by the kidneys.

What is the renal portal system?

The renal portal system begins and ends in a network of capillaries. Blood returning from the extremities (via the iliac veins) travels to the kidneys. Valves at the junction of the iliac veins and kidney (renal) veins steer blood either to the kidneys so metabolic waste products can be removed or directly to the heart via the posterior vena cava.

Explain the concept of the renal threshold of glucose.

The renal threshold of glucose is the amount of glucose that can be reabsorbed by the proximal convoluted tubules. If the blood glucose level gets too high, the amount of glucose that is filtered through the glomerulus exceeds the amount that can be reabsorbed (the renal threshold) and the excess is lost in urine. Fortunately, the renal threshold exceeds the normal amount of glucose found in blood, so 100% of the glucose filtered through the glomerulus is reabsorbed back into the body, and no glucose is lost in the urine. However, in pathologic conditions such as uncontrolled diabetes mellitus, where blood glucose levels can be extremely high because of insufficient insulin production, the amount of glucose filtered through the glomerulus exceeds the limit that can be reabsorbed by the PCT.

Describe how the respiratory and digestive passageways "switch places" in the pharynx.

The respiratory passageway (nasal passage) starts out dorsal to the digestive passageway (mouth) rostrally, but further caudally, the respiratory passageway (larynx) is ventral to the digestive passageway (esophagus).

How does the reproductive system differ from other body systems?

The rest of the body's systems work to ensure the survival of the individual animal they are part of, whereas the reproductive system works to ensure the survival of the species of animal. It interacts with other body systems, but purely reproductive structures are not essential to the life of an animal. Another difference from other body systems is that the reproductive system requires a second animal (of the opposite sex) to fully carry out its function, which is to produce a brand-new animal (the offspring).

List the two separate components of the avian stomach and their functions.

The stomach of birds consists of the glandular stomach (proventriculus) and the muscular stomach (gizzard). The glandular stomach is where chemical digestion begins. Its mucosa consists of columnar epithelial cells and mucosal glands that produce mucus to moisten food. The submucosal layer possesses digestive glands. These glands secrete pepsin, which begins the breakdown of proteins, and hydrochloric acid, which increases the acidity of the stomach to enhance the action of digestive enzymes. In birds the gastric juices can have a pH between 0.7 and 2.5. The muscular stomach consists of distinct bands of striated muscles that work to grind food components, such as bones, scales, and nuts. Also, many seedeaters and grain-eating birds actively seek and ingest small pieces of grit to aid in grinding food.

Compare and contrast the sympathetic and parasympathetic nervous systems. Include in your comparison the preganglionic and postganglionic neurons; the origin of preganglionic neurons; the neurotransmitters; and each system's impact on the heart, GI tract, blood vessels, bronchiole diameters, and the size of the pupil of the eye.

The sympathetic nervous system emerges from the thoracolumbar area. The parasympathetic system emerges from the brain and the sacral vertebral regions and therefore is called the cranial-sacral system. Outside the thoracolumbar area of the spinal column are a series of autonomic ganglia (many ganglions) that form a chain called the sympathetic ganglion chain. The sympathetic preganglionic neuron extends out from the spinal cord and either synapses with a neuron within the ganglion chain or passes through the ganglionic chain and synapses with a neuron located beyond the sympathetic chain. Each sympathetic preganglionic neuron usually synapses with many postganglionic neurons in a wide variety of locations in the sympathetic chain or in ganglions outside the sympathetic chain. The sympathetic postganglionic neuron extends the remaining distance to the target organ. The parasympathetic preganglionic neuron travels directly from the CNS to its target organ, where it synapses with a short postganglionic neuron in the target organ. Thus the parasympathetic preganglionic neuron is relatively long compared with the very short postganglionic neuron. The sympathetic nervous system primarily uses norepinephrine as its key neurotransmitter. The neurons associated with the parasympathetic nervous system secrete acetylcholine as their neurotransmitter. Heart rate: increased by sympathetic and decreased by parasympathetic system Force of heart contraction: increased by sympathetic; no significant effect from the parasympathetic system Diameter of bronchioles: increased (dilated) by sympathetic and decreased (constricted) by parasympathetic system Diameter of pupil: increased (dilated) by sympathetic and decreased (constricted) by parasympathetic system Gastrointestinal motility, secretions, and blood flow: decreased by sympathetic and increased by parasympathetic system Diameter of skin blood vessels: decreased by sympathetic system; no significant effect from parasympathetic system Diameter of muscle blood vessels: increased by sympathetic system; no significant effect from parasympathetic system Diameter of blood vessels to kidney: decreased by sympathetic system; no significant effect from parasympathetic system

Which part of the autonomic nervous system is responsible for the fight-or-flight response and which is responsible for the rest-and-restore system?

The sympathetic nervous system is responsible for the fight-or-flight system and the parasympathetic nervous system is responsible for the rest-and-restore system.

What factors stimulate contraction of the arrector pili muscle? Why is this muscle important?

The sympathetic nervous system stimulates the contraction of the arrector pili muscles when an animal is frightened or cold. This reaction is a defense mechanism designed to make the animal appear bigger and therefore less vulnerable to potential predators. In addition, hair that stands erect can better trap insulating layers of air than can nonerect hair, so animals with erect hair coats stay warmer than animals with flat coats. The arrector pili muscle also is responsible for forcing sebum from the sebaceous gland, which helps keep the integument moist and supple.

What is the basic cause of motion sickness?

There is a disagreement among the sensory receptors for the vestibular system, eyes, and proprioception, which can result in the unpleasant sensations of motion sickness, such as headache, nausea, and vomiting. The eyes look around the interior of the vehicle and see that nothing is apparently moving, but the equilibrium receptors and proprioceptors detect motion.

What is the most important function of neural tissue?

receive and transmit electrical and chemical signals throughout the body

What role do the synaptic cleft, presynaptic neuron, neurotransmitter, and postsynaptic neuron play in the continuation of a depolarization wave from one nerve to another?

The synapse is the junction between two neurons or a neuron and a target cell. The synapse consists of a physical gap between the two cells called the synaptic cleft. The neuron bringing the depolarization wave to the synapse and releasing the chemical to stimulate the next cell is called the presynaptic neuron. The chemical released by the presynaptic neuron is called the neurotransmitter, and the neuron that contains the receptors that receive the neurotransmitter is the postsynaptic neuron. In this way, depolarization continues from one cell to the next.

What is important about the scrotum's ability to adjust the position of the testes relative to the body?

The testes have to be kept slightly cooler than body temperature to produce spermatozoa. A bandlike muscle, the cremaster muscle, passes down through the inguinal ring and attaches to the scrotum. It can adjust the position of the testes relative to the body. In warm conditions, the cremaster muscle relaxes, and the testes hang down away from the warm body. This position helps to reduce their temperature. In cold conditions, however, the cremaster muscle pulls the testes up tight against the body wall, which helps to warm them.

What are the goals of transfusion therapy?

The three goals of therapy are to increase oxygen-carrying capacity, to replace coagulation factors or other proteins, and to replace volume.

List the three veins that are commonly used for venipuncture in birds. Where are they located?

The three most commonly used veins are the jugular vein, brachial vein, and medial metatarsal vein. The jugular veins are located ventrally, on each side of the trachea. The right jugular is larger than the left and is most commonly used for venipuncture in psittacines. The brachial vein is located on the ventral side of the wing, extending over the elbow and up the humerus. About halfway up the humerus, it joins the cutaneous ulnar vein and increases slightly in size. In raptors, the brachial vein is often used to take blood samples or insert temporary catheters for repeated intravenous treatments. The medial metatarsal vein is located on the ventral medial side of the leg, extending from the metatarsus dorsally over the heel joint.

List three types of mixture. How is each type similar to or different from the others?

The three types of mixtures are solutions, colloids, and suspensions. Solutions are homogeneous mixtures of various substances that can occur as gases, liquids, and solids. The size of the solutes is very small, consisting of only a few atoms. Colloids are also called emulsions and are translucent, heterogeneous mixtures that contain larger-sized solutes than those found in solutions. The solutes do not precipitate and remain suspended, which allows colloids to reflect light. Suspensions are heterogeneous mixtures containing large solutes that readily separate from the solution when stationary.

If you insert a hypodermic needle into a horse's muscle to give it an injection, which end fo the needle - the tip or the hub - is located deep in the muscle, and which end is located superficially?

The tip is deep and the hub is superficial.

What is the difference between the diploid chromosome number and the haploid chromosome number? In which body cells is each found?

The total number of chromosomes in the nucleus of each of the body's cells (except for the reproductive cells) is the same for all members of a species. This number is called the diploid chromosome number, which is always an even number because the chromosomes occur in pairs. The diploid chromosome number is sometimes expressed generically with the abbreviation 2n. The n is a mathematical expression that represents a number, and the 2 indicates that the number is doubled (diploid). The number of chromosomes in the reproductive cells is half the number in all other cells in the body. This is called the haploid chromosome number. It has to be reduced to half the diploid number so that when the spermatozoon and the ovum come together, the total number of chromosomes in the fertilized ovum gets back to the diploid number.

Describe the basic structure of the bronchial tree in the lung.

The trachea bifurcates to form two main bronchi. Each main bronchus enters the lung and divides into some fairly large branches, which divide into smaller and smaller branches called bronchioles. Bronchioles continue to subdivide down to the smallest air passageways, the microscopic alveolar ducts. These ducts end in groups of alveoli arranged like bunches of grapes, the alveolar sacs.

Why is it important that the ureters have an inner lining of transitional epithelium?

The transitional epithelium allows the ureters to stretch as urine is passed through them on its way to the urinary bladder.

How might examination of the bulbar and palpebral portions of the conjunctiva be useful as part of the overall physical examination of an animal?

The transparency of the conjunctiva allows the underlying tissues to show through, so it can be used as a window to see the blood vessels that are hidden elsewhere in the body by opaque structures, such as the skin. By looking through the conjunctiva at the lining of the eyelid, we can often detect abnormalities such as anemia (pale color caused by decreased blood flow), jaundice (yellowish color), and cyanosis (dark purplish color).

Describe the main structures that make up the umbilical cord and the function of each.

The umbilical cord is a tubelike structure that contains blood vessels (the umbilical arteries and vein) and a drainage tube from the fetus's urinary bladder (the urachus). The two umbilical arteries carry unoxygenated, waste-filled blood from the fetus to the placenta. The single umbilical vein carries nutrient- and oxygen-rich blood back from the placenta to the fetus. The urachus is a tube that runs from the cranial tip of the fetus's urinary bladder through the umbilical cord to the allantoic sac. The kidneys of the developing fetus are not fully functional through most of the pregnancy; therefore, they do not produce urine as we know it. They do, however, produce a watery fluid that must be removed from the urinary bladder. The urachus drains this fluid out into the allantoic sac.

What is the role of the upper CNS in the reflex arc? If the CNS influence is removed or blocked, do reflexes become hyporeflexive or hyperreflexive?

The upper CNS normally produces a dampening or inhibitory effect on the reflex arc. If it is removed, the reflex becomes hyperreflexive.

Where do the ureters terminate in reptiles and amphibians?

The ureters empty into the dorsolateral aspects of the urodeum instead of the urinary bladder. The urinary bladder, if present, is connected to the urodeum by a short, broad urethra. The urine enters the bladder for storage through the urodeum. It is important to note that crocodilians, snakes, and some species of lizards do not possess urinary bladders

What prevents urine from backing up into the ureters when the bladder wall contracts to expel urine?

The ureters enter the urinary bladder at such an oblique angle that when the bladder is full it collapses the opening of the ureter, preventing urine from backing up into the ureter. However, it doesn't prevent more urine from entering the bladder, because the strength of the peristaltic contractions is enough to force the urine through the collapsed opening into the urinary bladder.

How does the bladder know when to empty itself?

The urinary bladder constantly accumulates urine until the pressure of the filling bladder reaches a certain "trigger" point that activates stretch receptors in the bladder wall. When the trigger point is reached, a spinal reflex is activated that returns a motor impulse to the bladder muscles. The muscles of the bladder wall contract. These contractions are responsible for the sensation of having to urinate. In animals that are not housebroken, emptying of the bladder will occur at this point.

What is unique about the attachment between the skull and cervical spine of a reptile?

There is a single occipital condyle that forms the articulation between the skull and spine. This allows increased mobility of the head on the spine but also makes this connection relatively fragile, necessitating care when restraining reptiles.

Describe the functions of the uterus relating to pregnancy and parturition.

The uterus is the womb, where the fertilized ovum implants and lives while it grows and develops into a new animal. When fully developed, the uterus helps push the newborn out through the birth canal into the outside world. It forms part of the placenta, which is the life-support system that keeps the fetus alive while it develops during pregnancy. The uterus has to remain quiet during the pregnancy and contract powerfully at the time of birth. After it has delivered the newborn and the placenta (the afterbirth), it has to contract quickly to stop bleeding from the site where the placenta was attached to its lining. The uterus is vital to the success of reproduction. The fertilized ovum implants in the uterus and begins development. As the offspring develops, the placenta forms around it and attaches to the lining of the uterus so that nutrients, wastes, and respiratory gases can be exchanged between the fetal bloodstream and the maternal bloodstream. When the time comes for the offspring to be delivered, the muscular uterus provides most of the force necessary to open (dilate) the cervix so that the fetus can pass through it on its way to the outside world.

What is the difference between the visceral and parietal layers of pleura and peritoneum?

The visceral layer covers the organs, and the parietal layer lines the whole cavity.

What is the function of the vomeronasal organ?

The vomeronasal organ is an accessory olfactory organ. Snakes and lizards, such as monitors and tegus, have tongues that are deeply forked and function as a particle delivery system for the vomeronasal organ.

Diabetes insipidus gets its name from what physical characteristic of urine produced by patients with this disease?

The word insipid means tasteless. The disease diabetes insipidus was given its name because clinically it looked similar to diabetes mellitus, but the urine was "tasteless" rather than sweet because it didn't contain glucose.

What is the xiphoid?

The xiphoid is the caudalmost sternebra

List the nine air sacs and describe their main function in respiration.

There are nine total air sacs, four of which are paired. The pairs include cranial thoracic, caudal thoracic, cervical, and abdominal air sacs. The unpaired sac is the interclavicular air sac, which is located in the thoracic inlet between the clavicles. Air sacs are connected to the primary bronchi (abdominal sacs) or ventrobronchi (cervical, cranial thoracic, caudal thoracic, and interclavicular sacs) and serve the following functions: • They act as reservoirs for air and provide warmth and moisture to facilitate its diffusion through the lung capillaries. • They help in thermoregulation to cool the body by the internal evaporation of water. • They help provide buoyancy to water birds. Many species of penguins and diving birds have large posterior and abdominal sacs, the volume of which can be adjusted during diving and floating.

Why are clinical signs of renal failure not observed until the disease process is advanced?

There are often no clinical signs of chronic renal failure until 65% to 75% of the nephrons in both kidneys are nonfunctional. For this reason, long-term kidney disease is often not detected until very late in the disease.

Describe the three different lung structures found in reptiles.

There are three distinct lung morphologies in reptiles. The first is the unicameral lung (the most primitive), which is found in snakes and some lizards. It is a simple saclike structure. Typically, the cranial portion contains the tissues involved in gas exchange, and the relatively avascular caudal portion is comparable to the avian air sac. The second is the multicameral lung, found in chelonians, some lizards, and crocodilians. It is divided into many compartments and possesses intrapulmonary bronchi. The third type has an intermediate lung morphology and is called the paucicameral lung. It shares characteristics of both the unicameral and multicameral and is found most notably in iguanas and chameleons.

How are the hormones of the adrenal medulla involved in the fight-or-flight response?

These effects of the fight-or-flight response are produced partly by direct sympathetic nerve stimulation of target tissues and partly by the epinephrine and norepinephrine released into the bloodstream by the adrenal medulla. The adrenal medullary hormones circulate around the body, helping to produce the whole-body fight-or-flight effect. After the threat has passed, it takes the body a while to come down from its excited state. This delay results from the epinephrine and norepinephrine circulating in the bloodstream. It takes some time for them to be metabolized and removed from circulation.

Why are the smooth pleural surfaces important to the process of breathing?

These surfaces are lubricated with pleural fluid and ensure that the surfaces of the organs, particularly the lungs, slide smoothly along the lining of the thorax during breathing.

From what are the visceral and parietal vaginal tunics that cover the testes derived?

They are derived from layers of peritoneum that were pushed ahead of the testes as they descended through the inguinal rings. The very thin inner layer, the visceral vaginal tunic (also known as the proper vaginal tunic), is derived from the visceral layer of peritoneum that coated the testes as they developed in the abdomen. The thick outer layer, the parietal vaginal tunic (also known as the common vaginal tunic), is derived from the parietal layer of peritoneum that lines the abdominal cavity. It forms a fibrous sac around each testis and spermatic cord.

How do uroliths in cats differ from uroliths in other species?

They are much smaller and resemble sand rather than large stones.

Why do nonhuman animals often greet others by sniffing them?

They live in more of a smell-oriented world. They communicate and understand information by their sense of olfaction. For example, dogs obtain a huge amount of information from sniffing the air or an object where other animals have been.

How does the function of the bulbourethral glands differ from those of their eventual deposition in the female reproductive tract?

They secrete a mucinous (mucus-containing) fluid just before ejaculation that clears and lubricates the urethra for the passage of semen. The fluid from the bulbourethral glands is secreted in advance of the ejaculate and does not contribute greatly to its volume, composition, or function.

When milking a cow by hand, why does it take a minute or two of teat stimulation before milk starts to flow freely?

This is how long it takes for the sensory stimulation to reach the brain and signal the hypothalamus to release oxytocin from the posterior pituitary and for the oxytocin to reach the mammary gland via blood circulation.

Describe the suspensory apparatus of the udder.

This suspensory apparatus of the udder consists of a slinglike arrangement of ligaments that runs down the center and around the sides of the udder. The medial suspensory ligament contains many elastic fibers that allow it to stretch. It passes down the center between the left and right halves of the udder. The lateral suspensory ligaments are composed largely of strong, but relatively inelastic, collagen fibers. They pass down and around the lateral sides of each half of the udder. The strong lateral ligaments provide firm support for the udder, and the elastic medial ligament acts as a shock absorber for the udder as the animal moves around.

Name the different types of dentition found in reptiles.

Three types of dentition in reptiles are thecodont, pleurodont, and acrodont. Thecodont dentition, with the teeth arising from sockets in the skull bones, is found only in crocodilians. Acrodont dentition, with the teeth fused to the biting edge of the mandible and maxillae, is found in some species of lizards, such as those in the family Agamidae. Pleurodont teeth are attached to the periosteum on the medial aspects of both the mandibles and maxillae. Thecodont and pleurodont teeth are replaced periodically during the life of the animal, whereas acrodont teeth do not grow back if lost or broken.

List three types of muscle. How do they differ from one another?

Three types of muscle are skeletal, smooth, and cardiac. Skeletal muscle cells are striated, or striped, because histologically they have alternating bands of light and dark. Unlike cardiac and smooth muscle, skeletal muscle is usually controlled through conscious effort and therefore is called voluntary muscle. (In other words, the animal can control its movement through conscious thought.) Thus skeletal muscle is striated voluntary muscle. Smooth muscle is composed of small, spindle-shaped cells that lack striations or bands and therefore appear "smooth." Like skeletal muscle, smooth muscle may be stimulated to contract by the action of nerves, but unlike skeletal muscle, the contractions cannot be consciously controlled. Smooth muscle is therefore nonstriated involuntary muscle. Cardiac muscle exists only in the heart and possesses the remarkable ability to contract even when neural input has been altered. Specialized pacemaker cells within the heart muscle supply the signal for the heart to contract at regular intervals. This input is entirely involuntary and is responsible for initiating the pumping force that propels blood through blood vessels. Cardiac muscle is striated involuntary muscle.

What is threshold? What role does threshold play in the all-or-none principle?

Threshold is the number of sodium channels that must be opened in order for depolarization to occur. A stimulus must be strong enough for this threshold to be reached. According to the all-or-nothing theory, either the neuron depolarizes to its maximum strength or it does not depolarize at all (that is, the threshold is met or it isn't).

Which endocrine gland secretes hormones that regulate molting and the migratory urge?

Thyroid gland

Can you describe the events that occur in translation?

Translation is the process of making protein and occurs in the cytoplasm with the aid of ribosomes. Protein synthesis can occur either in cytosol, using free-floating ribosomes, or on rough endoplasmic reticulum (rRER), using fixed ribosomes. In the cytosol many free-floating ribosomes attach to a single strand of mRNA at the same time and begin "reading" the genetic sequence on the mRNA. The ribosomes that attach to the strand of mRNA form molecular "docking stations" that enable another molecule, transfer RNA (tRNA), to also bond to the mRNA strand. Each tRNA carries a specific amino acid and has a specific anticodon that correlates with the particular amino acid it carries. The "reading" process involves the bonding of a specific anticodon on the (tRNA to a complimentary codon on the mRNA. At the docking site tRNA molecules bond to the mRNA molecule, bringing the amino acids they carry into close approximation of one another. This allows the amino acids to bond directly to one another. Once the amino acid it carries is bonded to the adjacent amino acid, the tRNA molecule leaves the ribosome to pick up another amino acid. Over time a chain of amino acids, called a polypeptide chain, forms on the ribosome. When the chain has reached its required length, it disconnects from the ribosomal "docking station" and floats out into the cytosol (or if translation occurred on RER, the peptide is taken into the tubular cisternae of the RER for modification). Polypeptides are linked together to form proteins.

Describe the path of one breath of air through the respiratory system of a bird.

Two inhalations and two expirations are required to transport one pocket of air through the entire respiratory system. To begin the cycle, the first inhalation involves an expansion of the thoracoabdominal space (birds do not have a diaphragm, the major inspiratory muscle in mammals), creating a pressure gradient that brings air into the body. Most of the air flows into the posterior air sacs (abdominal and caudal thoracic), where it is warmed and humidified. With the first expiration, this air is pushed into the lungs, where gas exchange occurs. The second inspiration results in the air moving out of the lungs and into the anterior air sacs (cranial thoracic, cervical, and interclavicular), and the second expiration results in the air leaving the body through the trachea.

How many muscle layers are found in the esophagus? Which direction do the fibers run in each layer?

Two layers (inner circular and outer longitudinal)

How much kidney function must be destroyed before clinical signs of renal dysfunction become evident?

Two thirds (2/3) of the total nephrons in both kidneys must be nonfunctional before clinical signs of renal dysfunction start to become evident.

Name two types of sweat glands. How are they different from one another?

Two types of sweat glands are eccrine and apocrine. The excretory portion of the eccrine gland consists of a simple coiled tube located in the dermis or hypodermis and connected to the surface of the skin by a long duct. In dogs, eccrine sweat glands are found only in the deep layers of the fat and connective tissue of footpads. Like eccrine sweat glands, apocrine sweat glands have a coiled excretory portion buried in the dermis or hypodermis with a single excretory duct. However, unlike eccrine sweat glands, apocrine glands empty into hair follicles rather than onto the surface of the skin. In the dog, apocrine glands are located in the external ear canal.

How many layers of muscle make up the muscular layer of the wall of the intestines?

Two. Inner circular and outer longitudinal.

Which hypersensitivity reaction is likely involved in a vaccine reaction?

Type 1

Nitrogenous waste materials from protein breakdown are eliminated from the body primarily as what?

Urea

When ovulation occurs, what causes the ovum to enter the oviduct?

When ovulation takes place, the ovum is "caught" by the fimbriae of the infundibulum. The infundibulum is the enlarged opening at the ovarian end of each oviduct. At the time of ovulation, it more or less surrounds the area of the ovary where follicles have formed. The fimbriae are muscular, fingerlike projections that form the margin of the infundibulum. They "feel" along the surface of the ovary and position the infundibulum where the follicle or follicles are located. This helps ensure that the infundibulum is properly positioned to catch the ovum or ova when ovulation occurs. If ova miss the opening of the oviduct, they fall into the abdominal cavity, where they usually just disintegrate after a time.

How do the actions of gastrin on the stomach differ from those of secretin and cholecystokinin?

When released by stomach cells, gastrin stimulates gastric (stomach) glands to secrete hydrochloric acid and digestive enzymes, and it encourages muscular contractions of the stomach wall. Secretin and cholecystokinin are produced in the small intestine. Secretin stimulates the pancreas to secrete fluid rich in sodium bicarbonate into the duodenum to neutralize the acidic chyme from the stomach. Cholecystokinin stimulates the release of digestive enzymes from the pancreas into the duodenum. Both secretin and cholecystokinin also act on the stomach to inhibit gastric gland secretions and stomach motility. This slows the movement of chyme into the small intestine. They also stimulate the gallbladder of the liver to contract, sending bile down into the small intestine to aid the digestion and absorption of fats and fat-soluble vitamins.

Describe the basic processes by which oxygen moves from the air in the alveoli into the blood in the alveolar capillaries and how carbon dioxide moves in the other direction.

When that air is inhaled down into the alveoli of the lungs, it is only a couple of thin epithelial layers away from the blood in the surrounding capillaries. That alveolar capillary blood contains very little oxygen but a high level of carbon dioxide because it gave up its oxygen to the body's cells and picked up their carbon dioxide as it flowed through the systemic circulation. As this low-oxygen, high-carbon-dioxide blood circulates right next to an alveolus containing high-oxygen, low-carbon-dioxide air, oxygen diffuses from the alveolar air (area of high concentration) into the blood of the alveolar capillary (area of low concentration). At the same time, carbon dioxide diffuses from the blood (area of high concentration) into the alveolus (area of low concentration). The differences in the concentrations of the gases (the concentration gradient) stay fairly constant because as the blood picks up oxygen and dumps carbon dioxide, it flows away and is replaced by more low-oxygen, high-carbon-dioxide blood. At the same time, the air in the alveoli is refreshed with each breath.

How is the physical concept of inertia important to the functioning of the semicircular canals?

When the head moves in the plane of one of the semicircular canals, inertia causes the endolymph to lag behind the movement of the canal itself. The relative movement of the endolymph pulls on the cupula, which bends the hairs. This generates nerve impulses that give the brain information about the rotary motion of the head.

What happens to bones when the level of calcium in the blood falls too low? What happens when it rises too high?

When the level of calcium in the blood falls too low, osteoclast activity is increased to withdraw calcium from the bones and raise the blood calcium level. When the level of calcium in the blood rises too high, osteoblast activity is increased to deposit the excess calcium in the bones

How is the crossed extensor reflex tied in with the withdrawl reflex? Is the crossed extensor reflex an ipsilateral or contralateral reflex?

When the withdrawal reflex arc is stimulated, the afferent somatic sensory neuron also synapses with another set of interneurons, causing extensor muscles in the opposite leg to contract and thus support the weight of the body when the other leg flexes. Thus the withdrawal and crossed extensor reflexes are related. The crossed extensor reflex is a contralateral reflex.

Given that reptiles are unable to produce concentrated urine, how do they conserve water?

When water conservation is necessary, reptiles are able to absorb additional water from the urine through the wall of the urinary bladder, rectum, or cloaca, resulting in voided urine that is somewhat concentrated. Terrestrial reptiles produce uric acid as a protein waste product. Uric acid is relatively insoluble in blood and is voided via secretion from the renal tubules. Because uric acid is secreted rather than filtered, very little urine is needed to excrete it from the body. The renal portal system also allows water conservation. The renal portal veins arise from the veins of the tail and hind limbs if present. The renal portal vessels lead to capillary beds that perfuse the renal tubules but bypass the glomeruli. This anatomic configuration allows the reptile to discontinue blood flow to the glomeruli and decrease urine production during times of dehydration while maintaining blood flow to the renal tubules. Because blood flow to the tubules is maintained, ischemic necrosis is avoided and uric acid secretion continues.

In terms of form and function, how is brown fat different from white fat?

White adipose is found throughout the body, particularly in the deep layers of the skin. Initially, white adipocytes resemble fibroblasts, but as they fill with lipid, the organelles and nuclei are pushed to one side, and the cells become large spheres with eccentrically placed nuclei. As the cells swell, the cytosol is compressed into a thin, barely visible rim that surrounds the lipid droplet. Despite the compact condition of the cytoplasm, it continues to house all the organelles normally found in cells. During tissue preparation for microscopic examination, the lipid content of the adipocyte is extracted, leaving a large unstained space in the center of the cell. This, combined with the densely cellular nature of adipose tissue, lends itself to the "chicken wire" appearance that is evident microscopically. Brown adipose fat is found in newborn animals and in animals that hibernate during the winter. It is a highly specialized form of adipose and plays an important part in temperature regulation because it is a site of heat production. In brown fat, as in white fat, the nucleus is eccentrically placed; however, the cytoplasm in brown fat is clearly visible, and lipid is stored in multiple small vesicles rather than in a single large droplet. In brown fat, the energy derived from the oxidation of lipids and the energy released from electron transport are dissipated as heat, not adenosine triphosphate (ATP). For this reason, brown fat contains an exceptionally high number of mitochondria (the site of electron transport), which become darkly stained in the cytoplasm. This dark coloration gives brown fat its name. Brown fat is also more vascular than white fat. Its rich vascular network helps distribute the heat produced to many areas of the body. In this way, neonatal animals and hibernating animals can generate enough body heat during vulnerable periods (after birth and during the winter) to survive. Histologically, brown fat looks glandular and therefore is sometimes called the hibernating gland.

What is the difference between gray matter and white matter?

White matter refers to nervous tissue containing many myelinated axons. Nervous tissue that is made up largely of neuron cell bodies, which are not myelinated, appears darker and is called gray matter.

How would arthritis in the tiny joints of the ossicles affect hearing? Could this possibly affect the hearing of older animals?

Yes, arthritis could affect hearing in older animals. Arthritis could decrease the conduction of sound waves from the tympanic membrane to the oval window. The force of the vibrations would be decreased and the animal's hearing might be impaired.

Would a bilaterally cryptorchid animal exhibit normal male behavior? Why or why not?

Yes, because testosterone, which is responsible for the male libido, continues to be produced. Therefore, a bilaterally cryptorchid animal has all the characteristics of a male animal but cannot reproduce.

Do FSH and LH play important roles in male animals? If so, what are they?

Yes. In the male, FSH has an effect similar to one of its effects in the female. It stimulates spermatogenesis, the development of male reproductive cells (the spermatozoa) in the seminiferous tubules of the testes. In the male, LH stimulates cells in the testes called interstitial cells to develop and produce the male sex hormone testosterone. Therefore, LH is sometimes called interstitial cell-stimulating hormone (ICSH) in the male.

If trauma occurs in the segment of the spinal cord through which a particular reflex arc passes, will the reflex arc be hyperreflexive or hyporeflexive

hyporeflexive

Where does protein synthesis begin?

in the nucleus with transcription and ends in the cytoplasm with translation

In what skull bone is the upper incisor teeth found?

incisive bones

What is another name for cutaneous membrane?

integument

What is the name of the structure that is a continuation of the myocardium that forms a wall between the two atria? The two ventricles?

interatrial septum interventricular septum

The body's innate defense against viral pathogens is driven by the production of what?

interferons

In what skull bone is the lacrimal sac found?

lacrimal bone

The inside surface of a tooth that faces the tongue is the _____ surface.

lingual

Where is simple columnar epithelium found? (1 place)

lining the length of the gastrointestinal tract from stomach to rectum

What are two substances secreted by the exocrine portion of the pancreas?

lipase, amylase, nucleases, proteases, proenzymes

Which cell is the only white blood cell not capable of phagocytosis?

lymphocyte

In what skull bone is the lower teeth found?

mandible

In what skull bone is the upper cheek tooth found?

maxillary bones

What cellular process represents the largest demand for protein and enzymes?

metabolic turnover

Which white blood cell is the largest cell normally seen in peripheral blood?

monocyte

What is the name of a simple sugar?

monosaccharide

In the reticulorumen complexes carbohydrates are broken down to ____ or ____.

monosaccharides or polysaccharides

When speaking of the movement of the mandible, what is translation?

movement to the side and forward