A&P Final Exam Study Guide

Summarize the four events of the cross-bridge cycle.

- 1. Cross bridge formation. - 2. The power (working stroke). - 3. Cross bridge detachment. - 4.Cocking of the myosin head.

What two factors affect the conduction velocity of an action potential? Compare the speeds of continuous conduction and saltatory conduction.

- Axon diameter - Degree of myelination -Continuous conduction is relatively slow. - Saltatory conduction is about 30x faster than continuous conduction.

Describe the four major stages involved in the repair of a simple fracture. Use the terms bony callus, fibocartilaginous callus, and hemotoma in your answer.

- Hematoma formation: torn vessels result in bleeding that soon forms a clot. - Fibrocartilaginous callus forms: fibroblasts and chondroblasts invade the site and secrete a cartilaginous matrix that calcifies. - Bony callus forms: within the fibrocartilaginous callus, osteoblasts begin forming spongy bone. - Bone remodeling occurs: for several months, the bony callus is remodeled, so that excess material on the diaphysis and in the medullary cavity is removed.

Describe the difference between cells that end with the suffix -blast and those that end with the suffix -cyte. Give one specific example of each and describe their function.

- Immature -blast cells are actively mitotic and secrete the fibers and ground substance typical of a specific tissue. (Fibroblast secrete collagen proteins that maintain the frame work of the tissues.) - Mature-cyte cells are less active, and maintain the health of the tissue, although they may revert to more active -blast form, if needed for repair. (Lymphocyte help circulate blood in your body)

Compare and contrast intramembraneous and endochondral ossification. Specifically, from what type of cartilage or membrane does bone develop in each process? These processes form which bones found in the body? Also, name one feature that is similar and one which is different for each process.

- In endochondral ossification, bone tissue replaces hyaline cartilage, forming all bones below the skull except for the clavicles. - Intramembranous ossification forms membrane bone from fibrous connective tissue membranes, and results in the cranial bones and clavicles. - Both form cartilage into bone.

Give two examples of specific types of epithelium (for example, transitional epithelium), describing how the structure (anatomy) of the type of epithelium influences its function (physiology).

- Transitional epithelium forms the lining of the hollow organs of the _URINARY__ system and is specialized to allow cells to change shape and stretch as the organ distends. - PSEUDOSTRATIFIED_ columnar epithelium contains cells of varying heights that all sit on the basement membrane, giving the appearance of many layers, and _SECRETES_ or _ABSORBS__ substances, such as the lining of the respiratory tract.

What is the function of a neuron? What three special characteristics do neurons have? Describe the structure and function of the cell body and processes (dendrites and axons) found in neurons.

-Neurons are specialized cells that conduct messages in the form of electrical impulses throughout the body. -Neurons have extreme longevity, are amitotic, and have an exceptionally high metabolic rate and require continuous and abundant supplies of oxygen and glucose. - The neuron cell body consists of spherical nucleus surrounded by cytoplasm and act as part of the receptive region that receives information from other neurons. - Dendrites are short, tapering, diffusely branching extensions and act as the main receptive or input regions which provide an enormous surface area for receiving signals from other neurons. - Axon is a cone-shaped area of the cell body and acts as the conducting region of the neuron which generates nerve impulses and transmits them.

What is the difference between an action potential and a graded potential? Give two examples of graded potentials.

-Unlike graded potentials, action potentials do not decay with distance. - Depolarizations -Hyperpolarization

Describe why the skin is considered an organ. (Hint: What 2 tissue type are in skin, and where are they found?)

-the outermost epidermis, an epithelial tissue; and the inner dermis a connective tissue.

What are the name of the two layers of the dermis? Where are they located relative to each other (superficial, deep)? What type of connective tissue is in each? What different cells or fibers are in each layer?

-the thin, superficial papillary dermis (Areolar, collagen and elastin fibers , ibroblasts, macrophages, adipocytes, mast cells, Schwann cells, and stem cells.)and the deeper reticular dermis(Dense Irregular, thick elastic fibers and collagen, fibroblasts, macrophages, and mast cells).

Summarize the four steps involved in generating an action potential.

1. Resting state: All voltage-gated Na+ and K+ channels are closed. 2. Depolarization: Voltage-gated Na+ channels open. 3. Repolarization: Na+ channels are inactivating, and voltage-gated K+ channels open. 4. Hyperpolarization: Some K+ channels remain open, and Na+ channels reset.

Name and describe the six functions of epithelial tissue.

1.Protection-first line of defense, 2.Sensation-nerve ending reacts to touch, pressure, heat, and cold 3.Heat regulation- body temp. 4.storage and synthesis-storage center for lipids and water 5.excretion-eliminates urea when you sweat 6.Absorption-oxygen,nitrogen, and carbon dioxide enter your skin in small amounts

What are seven criteria on which skeletal muscles are named?

Criteria used to name skeletal muscles include location, shape, size, direction of muscle fibers, number of origins, location of attachments, or action. A muscle name often incorporates more than one of these criteria.

Describe how the skin accomplishes four of its functions.

Protects from the sun Senses the hand when burning Store necessary macromolecules Regulates body temp

Explain how the carbonic acid-bicarbonate buffer system works to maintain pH homeostasis in the blood when (a) the blood pH rises, and (b) the blood pH falls.

When any acidic substance enters the bloodstream, the bicarbonate ions neutralize the hydronium ions forming carbonic acid and water. Carbonic acid is already a component of the buffering system of blood. Thus hydronium ions are removed, preventing the pH of blood from becoming acidic.

Among the twelve pairs of ribs, name which are "true" ribs and which are "false" ribs, and explain what this means.

- 1-7 True Ribs - 8-12 False Ribs - 11-12 Floating Ribs - Distinguish among true ribs, false ribs, and floating ribs: true directly connected to sternum, false not directly connected to sternum, floating not connected at all

Summarize the three events involved in the generation and propagation of an action potential in a skeletal muscle fiber.

- 1. An end plate potential is generated at the neuromuscular junction. - 2. Depolarization: Generating and propagating an action potential. - 3. Repolarization: Restoring the sarcolemma to its initial polarized state (negative inside, positive outside)

Describe the four steps involved in excitation-contraction coupling.

- 1. The action potential propagates along the sarcolemma and down the T tubules. - 2. Calcium ions are released. - 3. Calcium bind to troponin and removes the blocking action of tropomyosin. - 4. Contraction begins.

What is the concept of "threshold" in firing an action potential? At what voltage does this typically occur? Why is an action potential described as an "all or none" phenomena?

- A critical minimum, or threshold, depolarization is defined by the amount of influx of Na+ that at least equals the amount of efflux of K+. - 100 mV (from -70 mV to +30 mV) - They either happen completely, in the case of a threshold stimulus, or not at all, in the event of a subthreshold stimulus.

Summarize four ways how the action of a muscle can be inferred by the position of the muscle relative to the joint it crosses.

- A muscle that crosses on the anterior side of a joint produce flexion. - A muscle that crosses on the posterior side of a joint produce extension. - A muscle that crosses on the lateral side of a joint produce abduction. - A muscle that crosses on the medial side of a joint produces adduction.

Compare and contrast the gross anatomy of spongy and compact bone. Use the terms trabeculae, endosteum, periosteum, red marrow, and yellow marrow in your answer.

- All bone has a dense outer layer consisting of compact bone that appears smooth and solid. - Internal to compact bone is spongy bone, which consists of needle-like or flat pieces, called trabeculae. - Short, irregular, and flat bones consist of thin plates of periosteum-covered compact bone on the outside and endosteum-covered spongy bone inside, called diploe, which houses bone marrow (YELLOW OR RED) between the trabeculae.

Describe three characteristics of connective tissue that set them apart from other primary tissues.

- All connective tissue arises from an embryonic tissue called mesenchyme. - Connective tissue ranges from avascular to highly vascularized. - Connective tissue is composed mainly of nonliving extracellular matrix that separates the cells of the tissue.

Compare and contrast the muscle response to: (1) changes in stimulus frequency and (2) changes in stimulus strength.

- An increase in the frequency of stimulation causes temporal summation. The higher the frequency, the greater the strength of contraction of a given motor unit. - An increase in the strength of stimulation causes recruitment. The stronger the stimulation, the more motor units are activated, and the stronger the contraction.

Summarize the structure and function of the four neuroglia in the CNS and the two neuroglia in the PNS.

- Astrocytes shaped like delicate branching sea anemones and support and brace the neurons and anchor them to their nutrient supply lines. - Microglial cells are small and ovoid with long thorny processes which monitor health, and sense when certain neurons are injured or in other trouble. - Ependymal cells from squamous to columnar many are ciliated which form a permeable barrier between the CSF that fills those cavities. - Oligodendrocytes also branch but with fewer processes provide and insulating covering. -Satellite cells surround neuron cell bodies with a widely unknown function. - Schwann cells surround all nerve fibers forming the myelin sheath.

Name the four classes of organic compounds found in living systems, describe the building blocks of each, and explain the chemical reactions used for their (a) synthesis and (b) breakdown.

- CARBOHYDRATES are a group of molecules, classified as either monosaccharides, disaccharides, or polysaccharides, that contain carbon hydrogen and oxygen, and include sugars and starches. -MONOSACHHARIDES are simple sugars, named for the number of carbons they contain, that are single-chain or single-ring structures. - DISACCHARIDES are formed when two monosaccharides are joined by dehydration synthesis. -POLYSACCHARIDES are long chains of monosaccharides linked together by dehydration synthesis: two biologically important polysaccharides are starch and glycogen. - Lipids are INSOLUBLE in water, but dissolve readily in nonpolar solvents, and include triglycerides, phospholipids, steroids, and other lipoid molecules. - The fatty acids may be either SATURATED, having only single bonds between adjacent carbons, or UNSATURATED, bearing at least one double bond between a pair of carbons in the chain. of glycerol (a sugar alcohol), and fatty acids (linear hydrocarbon chains). - PHOSPHOLIPIDS are diglycerides with a phosphorus-containing group and two fatty acid chains that are primarily used to construct cell membranes. - STEROIDS, all deriving from cholesterol, are flat molecules made up of four interlocking hydrocarbon rings and are used in the body in cell membranes and hormones. - EICOSANOIDS are derived from arachidonic acid, and function in blood clotting, and regulation of blood pressure, inflammation, and labor contractions. - PROTEINS are the basic structural material of the body and play vital roles in cell function. - Proteins are long chains of AMINO ACIDS connected by PEPTIDE bonds, which join the amine of one amino acid to the acid of the next. - NUCLEIC ACIDS have 2 primary classes: deoxyribonucleic acid (DNA) & ribonucleic acid (RNA). - NUCLEOTIDES are the structural units of nucleic acids and consist of three components: a nitrogen-containing BASE, a pentose SUGAR, and a PHOSPHATE group. - In DEHYDRATION SYNTHESIS, a hydrogen atom is removed from one monomer, and a hydroxyl group is removed from the atom to be paired with, resulting in a covalent bond forming between the monomers, and the production of a water molecule from the combination of the hydrogen and hydroxyl. - In HYDROLYSIS, a water molecule is used to split the covalent bond between two atoms, in reverse of dehydration synthesis.

Describe how cell adhesion molecules (CAMs), contact signaling, chemical signaling, and G protein-linked receptors allow the cell to interact with its environment.

- Cell adhesion molecules (CAMs) are glycoproteins that attach cells to extracellular molecules, pull migrating cells through their environment, act as signals to immune cells, and maintain tight junctions. - Contact signaling involves touch between membrane receptors of neighboring cells to facilitate recognition between cells. - Chemical signaling involves the binding of a chemical signal (a ligand) to a membrane receptor, resulting in the initiation of cellular responses. - G protein-linked receptors act indirectly to activate a messenger system that typically is involved in phosphorylation of a molecule by ATP.

Summarize what happens in the three steps of tissue repair.

- Cellular damage promotes inflammation, which prepares the area for the repair process. - Organization replaces the blood clot with granulation tissue, restoring blood supply. - Regeneration and fibrosis restore tissue.

Name the four major regions of the adult brain. What is the primary function of each?

- Cerebral Hemispheres receive sensory impulses from, and dispatches motor impulses to, the opposite side of the body. - Diencephalon coordinating with the endocrine system to release hormones and relaying sensory and motor signals to the cerebral cortex. - Brain Stem regulates vital cardiac and respiratory functions. - Cerebellum processes and interprets impulses from the motor cortex and sensory pathways and coordinates motor activity so that smooth, well-timed movements occur.

Name the four curvatures of the vertebral columns in order, from superior to inferior, and the number of bones in each region. Which curvatures concave posteriorly, and which convex posteriorly? What function does this serve?

- Cervical (7) Concave - Thoracic (15) Convex - Lumbar (5) Concave - Sacral (5) Convex - The curvatures of the spine increase resiliency and flexibility of the spine.

What are the two bones found in each pectoral girdle? Relate the structure of these bones to the function of the girdle.

- Each pectoral girdle consists of a clavicle and a scapula. - The clavicle or collarbone is an S-shaped bone situated at the front of your body in a horizontal position. It supports your shoulder, encourages a full range of motion, and protects your nerves and blood vessels that pass between the trunk of your body and your upper limbs. - Unlike your clavicle, the scapula bone or shoulder blade is located at the back of your shoulder. It's triangular and connects your humerus with your clavicle. The scapula provides an attachment point for a number of muscles in your shoulder and upper limbs to your neck and back.

Describe the structural and organizational levels of skeletal muscle. Use the terms muscle fiber, sarcolemma, sarcomere, organ, myofilament, actin, myosin, myofibril, and fascicle.

- Each skeletal muscle is a discrete organ, in which muscle fibers predominate, but also includes blood vessels, nerves, and connective tissue. Skeletal muscle fibers are large, cylindrical cells with multiple nuclei beneath the sarcolemma, or plasma membrane. Myofilaments make up the myofibrils and consist of thick(myosin) and thin (actin) filaments. Myofibrils account for roughly 80% of cellular volume and contain the contractile elements of the muscle cell.

Compare the structure and locations of sweat and oil glands and compare the composition and functions of their secretions.

- Eccrine, or merocrine, sweat glands produce true sweat and are especially abundant on the palms of the hands, soles of the feet, and forehead. (COILED AND TUBULAR) - Secretion of eccrine glands is regulated by the sympathetic nervous system and is used to prevent the body from overheating. - Sabaceous glands secrete sebum, an oily secretion, and are found all over the body, except the palms of the hands and soles of the feet. (BULB LIKE NEXT TO HAIR FOLLICLE) - Sebum functions to soften and lubricate the hair and skin, slow water loss, and is bactericidal.

Compare and contrast the forms of vesicular transport: endocytosis (including phagocytosis, pinocytosis, and receptor-mediated), exocytosis, transcytosis, and vesicular trafficking.

- Endocytosis moves molecules into the cell by creating an infolding that forms a vesicle, which is then detached from the membrane and either combined with a lysosome or transported across the cell and out by exocytosis. - Phagocytosis is an endocytotic process in which large, solid materials are brought into the cell, and is often used by phagocytes, cells that dispose of debris and pathogens. - Pinocytosis is an endocytotic process aimed at taking a small volume of extracellular fluid with dissolved solutes into the cell and is often used by cells to sample the extracellular environment. Receptor-mediated endocytosis is the main mechanism for the specific exocytosis and transcytosis of most macromolecules and allows cells to concentrate molecules found in small amounts in extracellular fluid. - Exocytosis is a type of vesicular transport that moves molecules out of the cell to the extracellular environment, and is often used for secretion, or removal of wastes from the cell. - Transcytosis, the vesicular transport of macromolecules from one side of a cell to the other, is a strategy used by multicellular organisms to selectively move material between two environments without altering the unique compositions of those environments. - Vesicle trafficking is the biological process by which vesicles, including synaptic vesicles, transport materials between different cellular compartments and between a cell and its environment.

Describe the structure and function of enzymes, and include a description of specificity, active sites, and activation energy. What are the three basic steps involved in enzyme action?

- Enzymes are globular proteins that act as biological CATALYSTS, enabling biological processes to happen quickly enough to support life. - Enzymes may be purely PROTEIN or may consist of two parts, the protein APOENZYME and non protein COFACTOR, that are collectively called a holoenzyme. - Each enzyme is chemically specific, binding only certain SUBSTRATES, and possesses an ACTIVE SITE, the location on the protein that catalyzes the reaction. - Enzymes work by lowering the energy required by a reaction, the ACTIVATION ENERGY. - Substrates BIND to the active site on the enzyme, forming an enzyme-substrate complex - The enzyme-substrate complex undergoes internal REARRANGEMENTS that form PRODUCTS. - The enzyme RELEASES the product of the reaction.

Name the four types of tissue, describe their major function, and give an example of each.

- Epithelial COVERS/LINES (Skin) - Connective _SUPPORTS__ (Bone) - Muscle __MOVES__ (Heart) - Nervous __CONTROLS___ (Brain)

Describe in detail the four characteristics of muscle tissue.

- Excitability, or responsiveness, is the ability to receive and respond to a stimulus. - Contractility is the ability to contract forcibly when stimulated. - Extensibility is the ability to be stretched. - Elasticity is the ability to resume the cells' original length once stretched.

What are the three classes of levers? Where is the load, fulcrum, and effort located in each? Name where each of these occurs in the body.

- First-class levers have the effort applied at one end and the load at the other end, with the fulcrum in between. (raising head off the chest) - Second-class levers have the effort applied at one end, the fulcrum at the other end, and the load in between and provide strength but not speed or range of motion. (standing on tip-toe) - Third-class levers have the effort applied between the load and the fulcrum and provide for rapid, extensive movements. (flexing of the forearm)

Name and describe the three functional classifications of joints and give an example of where each is found in the body.

- Functional classification is based on the amount of movement allowed at the joint: synarthroses are immovable joints (sutures) , amphiarthroses are slightly movable (pubic symphysis), and diarthroses are fully movable (elbow).

Compare and contrast the forms of passive transport (simple diffusion, facilitated diffusion, osmosis) and the forms of active transport (primary and secondary).

- In Simple diffusion, very small molecules or lipid soluble molecules cross the cell membrane unassisted. - In Facilitated diffusion, sugars, amino acids, or ions are moved through the plasma membrane by binding to protein carriers in the membrane or by moving through channels. - Osmosis is the diffusion of water through a selectively permeable membrane. - In primary active transport, the energy to do work comes directly from hydrolysis of ATP by transport proteins called pumps. - In secondary active transport, transport is driven by energy stored in concentration gradients of ions created by primary active transport pumps. Secondary active transport systems always move more than one substance at a time using a cotransport protein.

What two processes are involved in bone remodeling, and what cells are involved in each process? Describe the two control loops which serve as "masters" for the bone modeling which continuously occurs in the body.

- In adult skeletons, bone deposit and resorption occur beneath the periosteum and endosteum. Osteoclasts secrete acid and lysosomal enzymes that break down bone matrix, absorb the components, and release them to the interstitial fluid. - An osteoid seam of gauzy-looking bone indicates the area of new bone deposition; it is separated from older mineralized bone by a transition zone called a calcification front. Osteoid becomes calcified through stimulation of osteoblasts, causing the release matrix vesicles containing alkaline phosphatase, that combine free Ca++ and phosphates, forming crystals that give rise to hydroxyapatite. - Maintaining Ca+ homeostasis: A hormonal negative feedback loop involving parathyroid hormone maintains Ca2+ homeostasis in the blood. - Keeping bone strong: Mechanical and gravitational forces acting on a bone drive remodeling where iti is required to strengthen that bone

Describe the difference among ionic bonds, nonpolar covalent bonds, polar covalent bonds, & hydrogen bonds.

- Ionic bonds are chemical bonds that form between two atoms that TRANSFER one or more electrons from one atom to the other. - Nonpolar molecules have a BALANCED distribution of the shared electrons' charge across the bond. - In POLAR molecules, electrons are more attracted to one atom (an electronegative atom) than the other (an electropositive atom), resulting in the area of the bond closest to the electronegative atom assuming a partial negative charge, while the area close to the electropositive atom takes on a partial positive charge. - HYDROGEN bonds are formed when a hydrogen that is covalently bonded to one atom (often oxygen or nitrogen) is attracted to another electronegative atom, forming a sort of "bridge."

How do meninges, cerebrospinal fluid, and the blood brain barrier protect the central nervous system?

- Meninges are three connective tissue membranes that cover and protect the CNS, protect blood vessels and enclose venous sinuses, contain cerebrospinal fluid, and partition the brain. -CSF gives buoyancy to the brain, protects the brain and spinal cord from impact damage, and is a delivery medium for nutrients and chemical signals. - The blood brain barrier is a mechanism that helps maintain a protective environment for the brain. (allowing certain things to pass the CSF)

Describe how negative and positive feedback maintain body homeostasis and provide an example of each.

- Most homeostatic control mechanisms are negative feedback mechanisms that REDUCE or STOP the effect of the stimulus, preventing severe changes within the body. (Opposite) - Blood sugar regulation (insulin lowers blood glucose when levels are high ; glucagon raises blood glucose when levels are low) - Positive feedback mechanisms ENHANCE the effect of the stimulus, resulting in an amplifying effect of the stimulus, creating cascades that are used to control events that do not require continuous adjustment. - During labor, as uterine contractions begin, levels of the hormone, oxytocin, continuously rise to further stimulate more contractions.

What is the difference in function between the sensory (afferent) and motor (efferent) divisions of the PNS? Name and describe the two parts of the motor division.

- Motor efferent carries impulses away to the effector organs while the other bring it from the organs. - Somatic nervous system has somatic motor nerve fibers that conduct impulses from the CNS to skeletal muscles. (voluntary) - Autonomic nervous system consists of visceral motor nerve fibers that regulate the activity of smooth muscles, cardiac muscles, and glands. (involuntary)

What is the function of the myelin sheath on neurons? How is myelination different in the PNS and in the CNS?

- Myelin protects and electrically insulates fibers, and it increases the transmission speed of nerve impulses. - Myelin sheaths in the PNS are formed by Schwann cells, which indent to receive an axon and then wrap themselves around it in a jelly roll fashion. -However, in the CNS, it is the oligodendrocytes that form myelin sheaths and can wrap around many axons.

Describe how differences in ionic composition and differences in plasma membrane permeability help generate the resting membrane potential.

- Negatively charged proteins help to balance the positive charges of intracellular cations. - K+ flowing out of the cell causes the cell to become more negative inside. Na+ trickling into the cell makes the cell just slightly more positive than it would be if only K+ flowed.

Name and describe the function of the 12 cranial nerves.

- Olfactory- detects odors - Optic- responsible for vision - Oculomotor, Trochlear, and Abducens- allow eyeball movement - Trigeminal- allow facial sensation and motor control of chewing muscle - Facial- allow movement of muscles creating facial expression - Vestibulocochlear- responsible for hearing & balance - Glossopharyngeal- control the tongue and pharynx - Vagus- control several visceral organs - Accessory- have a relationship with the vagus nerves - Hypoglossal- innervate muscles of the tongue

For the 12 cranial nerves, which have sensory function? Motor function? Both?

- Optic and Olfactory (I & II) - Oculomotor, Trochlear, Abducens, Accessory, and Hypoglossal (III, IV, VI, XI, & XII) - Trigeminal, Facial, Vestibulocochlear, Glossopharyngeal, and Vagus (V, VII, VIII, IX & X)

Name the bones of the lower limb and describe their location and number. (Word bank: leg, phalanges, metatarsals, tarsals, femur, patella, foot, thigh, fibula, kneecap, tibia)

- Phalanges (28) Foot - Metatarsals (10) Foot - Tarsals (14) Foot - Patella (2) Kneecap - Fibula (2) Leg - Tibia (2) Leg - Femur (2) Thigh

Name the bones of the upper limb and describe their location and number. (Word bank: phalanges, metacarpals, carpals, ulna, Humerus, arm, radius, hand, forearm)

- Phalanges (28) Hand - Metacarpals (10) Hand - Carpals (16) Hand - Ulna (2) Forearm - Humerus (2) Arm - Radius (2) Forearm

Describe in detail the five distinguishing characteristics of epithelial tissues. Include the terms apical surface, basal surface, reticular lamina, and basement membrane in your descriptions.

- Polarity: Tissue has an _APICAL_ surface not attached to surrounding tissues facing either the external environment or the cavity of an internal organ, and a _BASAL_ surface attached to the underlying connective tissue. - Specialized contacts: Adjacent epithelial cells are bound together by specialized contacts such as _DESMOSOMES_ and __TIGHT JUNCTIONS - Supported by connective tissue: A _BASEMENT_ membrane, consisting of a BASAL_ lamina, and a _RETICULAR_ lamina derived from the collagen of underlying connective tissue. - Epithelial tissues are _INNERVATED_, but _AVASCULAR_ receiving nutrients by diffusion from underlying connective tissues. - Epithelial tissue has a high __REGENERATION__ capacity.

What is a reflex? What are two types of reflexes? What are the components of the reflex arc?

- Reflexes are unlearned, rapid, predictable motor responses to a stimulus and occur over highly specific neural pathways called reflex arcs. 1. Inborn, or intrinsic, reflexes are unlearned, unpremeditated, and involuntary. 2. Learned, or acquired, reflexes result from practice, or repetition. A reflex arc is a very specific neural path that controls reflexes and has five components: a receptor, a sensory neuron, an integration center, a motor neuron, and an effector.

Name and describe the three structural classifications of joints and give an example of where each is found in the body.

- Structural classification focuses on the material binding the bones together and whether or not a joint cavity is present, which gives rise to three classes: fibrous, cartilaginous, and synovial. - Fibrous- bones are joined together by fibrous tissue and lack a joint cavity and provide little to no movement. Sutures on the skull - Cartilaginous - The bones are joined together by cartilage, lack a joint cavity, and have very little mobility. Pubic symphysis - SynoviaL joints have a fluid-filled joint cavity that allows free movement about the joint. Knee joint - Functional classification is based on the amount of movement allowed at the joint: synarthroses are immovable joints (sutures) , amphiarthroses are slightly movable (pubic symphysis), and diarthroses are fully movable (elbow).

Describe in detail four important functions of bone.

- Support: bones provide a framework for the body and surrounds soft organs. - Protection: bones protect the brain and vital organs. - Anchorage: skeletal muscles attach to bones with tendons. - Mineral storage: bones store calcium and phosphate. - Blood cell formation: hematopoieis occurs within red bone marrow. - Triglyceride storage: fat is stored in yellow bone marrow. - Hormone production: production of osteocalcin, that helps regulate insulin secretion.

Describe the differences in structure, location, and functions between the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). Use the terms ganglia, spinal cord, spinal nerves, brain, cranial nerves.

- The CNS consists of the brain and spinal cord is the integrating and control center of the nervous system. - The PNS consists mainly of nerves that extend from the brain and spinal cord, and ganglia, such as the spinal and cranial nerves and serves to connect the CNS to the limbs and organs.

Describe the two divisions of the cranium and describe four functions of facial bones.

- The cranial vault also called the calvaria forms the superior, lateral, posterior aspects of the skull, as well as the forehead. - The cranial base forms the skull's interior aspect. Internally, prominent bony ridges divide the base into three distinct steps or fossae the anterior, middle ,or posterior cranial fossae. The brain sits snugly in these cranial fossae, completely enclosed by the cranial vault. - The cranial and facial bones form the framework of the face and contain cavities for special sense organs, provide openings for air and food passage, secure the teeth, and anchor muscles of facial expression.

Describe four patterns of muscle fascicle arrangement.

- The fascicular pattern is circular when the fascicles are arranged in concentric rings. - A convergent muscle has a broad origin, and its fascicles converge toward a single tendon of insertion. - In a parallel arrangement, the length of the fascicles runs parallel to the long axis of the muscle. - In a pennate pattern, the fascicles are short and they attach obliquely to a central tendon that runs the length of the muscle.

What is the fluid mosaic model of the plasma membrane? Name and describe the function of the three types of membrane lipids and two types of membrane proteins found in the plasma membrane.

- The fluid mosaic model of membrane structure depicts the plasma membrane as an exceedingly thin (7-10 nm) structure composed of a double layer, or bilayer, of lipid molecules with protein molecules "plugged into" or dispersed in it. The proteins, many of which float in the fluid lipid bilayer, form a constantly changing mosaic pattern. - The plasma membrane is a fluid bilayer of lipids (phospholipids, cholesterol, and glycolipids) within which proteins are inserted. The lipids have both hydrophilic and hydrophobic regions that organize their aggregation and self-repair. The lipids form the structural part of the plasma membrane. - Most proteins are integral transmembrane proteins that extend entirely through the membrane. Some are peripheral proteins that are not embedded in the lipid bilayer. Proteins are responsible for most specialized membrane functions: Some are enzymes, some are receptors, and others mediate membrane transport functions.

Explain the principle of complementarity and provide 3 examples found in the human body.

- The principle of complementarity of structure and function is based on the fact that what a structure can do is related to its form. - Bones can support and protect body organs because they contain hard mineral deposits. - Various shapes of our teeth reflect their different actions. - Blood flows in one direction throughout the heart because the heart has valves that prevent backflow.

Explain 2 reasons why many chemical reactions in the body are irreversible and give specific examples.

- The reactants can change to the products, but the products cannot change back to the reactants or sometimes there isn't enough energy. - For example, when our cells break down glucose during cellular respiration to yield carbon dioxide and water, some of the energy released is trapped in the bonds of ATP. - Furthermore, if a product of a reaction is continuously removed from the reaction site, it is unavailable to take part in the reverse reaction. This situation occurs when the carbon dioxide that is released during glucose breakdown leaves the cell, enters the blood, and is eventually removed from the body by the lungs.

How is the resting membrane potential (RMP) established and maintained by the Na+-K+ pump? Which is the key player—K+, Na+, or Cl-, contributing to the RMP and why?

- The resting membrane potential is largely determined by K+ because at rest, the membrane is much more permeable to K+ than Na+. The active transport of sodium and potassium ions by the Na+-K+ pump maintains the Na+ and K+ concentration gradients.

Name and describe the differences among the four layers of the epidermis found in thin skin.

- The stratum basale (basal layer): deepest epidermal layer; the site of mitosis. - The stratum spinosum (prickly layer): several cell layers thick; contains keratinocytes, melanin granules, & highest concentration of dendritic cells. - The stratum granulosum (granular layer) contains keratinocytes that are undergoing a great deal of physical changes, turning them into the tough outer cells of the epidermis. - The stratum corneum (horny layer): outermost protective layer of the epidermis composed of a thick layer of dead keratinocytes.

Name & describe the function of the three types of cell junctions, and in what types of cells they may be found.

- Tight junctions are impermeable junctions. (epithelial cells) Desmosomes mechanically couple cells into a functional community. (heart muscles) Gap junctions allow joined cells to communicate. (smooth tissue)

Describe 4 reasons why water is important for body homeostasis and explain the chemistry behind each reason.

- WATER is the most important inorganic molecule and makes up 60-80% of the volume of most living cells. - Water has a high HEAT CAPACITY, meaning that it absorbs and releases a great deal of heat before it changes temperature. - Water has a high HEAT OF VAPORIZATION, meaning that it takes a great deal of energy (heat) to break the bonds between water molecules. - Water, called the UNIVERSAL SOLVENT, is a polar molecule that plays a role in dissociation of ionic molecules, forms hydration layers that protect charged molecules from other charged particles, and functions as an important transport medium in the body. - Water is an important REACTANT in many chemical reactions. - Water forms a protective CUSHION around body organs.

What is the sliding filament model of contraction? In particular, describe motion of the actin and myosin filaments, how cross bridges form, and how the following structures change/not change in size: sarcomere, I bands, Z discs, H zones, A bands.

- When the nervous system stimulates muscle fibers, the myosin heads on the thick filaments latch onto myosin-binding sites on actin in the thin filaments, and the sliding begins. - These cross bridge attachments form and break several times during a contraction, acting like tiny ratchets to generate tension and propel the thin filaments toward the center of the sarcomere. - As this event occurs simultaneously in sarcomeres throughout the cell, the muscle cell shortens. - At the microscopic level, the following things occur as a muscle cell shortens: - - The I bands shorten. - The distance between successive Z discs shortens. As the thin filaments slide centrally, the Z discs to which they attach are pulled toward the M line (Figure 9.6 STEP 2). - The H zones disappear. - The contiguous A bands move closer together, but their length does not change.

Name the three types of skeletal muscle connective tissue and describe their specific location in muscle.

- endomysium surrounds each muscle fiber, perimysium surrounds groups of muscle fibers, and epimysium surrounds whole muscles.

Name and describe the function of the five types of cells found in bone tissue.

- osteoprogenitor cells are stem cells located in the bone that play a prodigal role in bone repair and growth. - osteoblasts that secrete bone matrix - osteocytes and bone lining cells that monitor and maintain bone matrix - osteoclasts that are involved in bone resorption.

Explain the two ways glands can be classified, in terms of (1) the number of cells they have, and (2) where they release their product (endocrine vs. exocrine).

-Endocrine glands are ductless glands that secrete hormones by exocytosis directly _INTO_ the _BLOOD__ or lymph. (Multicellular) - Exocrine glands have _DUCTS_ and secrete their product onto a surface or into body cavities. (Unicellular or Multicellular) - _UNICELLULAR__ exocrine glands secrete _MUCUS_ to epithelial linings of the intestinal or respiratory tract. - Multicellular exocrine glands consist of a duct, and a group of secretory cells, and may be classified by duct _STRUCTURE_, or mechanism of __SECRETION__.