BIO 9 Exam #4

What is meant by 20/20 vision?

"Normal" vision is 20/20. This means that the test subject sees the same line of letters at 20 feet that person with normal vision sees at 20 feet. 20/40 vision means that the test subject sees at 20 feet what a person with normal vision sees at 40 feet.

Define what a stimulus is and recognize the various types of stimuli?

- A detectable change in the internal or external environment. - That which influences or causes a temporary increase of physiological activity or response in the whole organism or in any of its parts. -evoke a response or has an influence on a system to act EX) light - photoreceptors in the eye sound - vibration receptors in the ears touch, pressure, pain and temperature - different receptors in the skin taste and smell - chemical receptors in the tongue and nose position of the body - receptors in the ears

Name and identify the five major neurotransmitters and whether they are inhibitory or excitatory and what parts of the body they effect.

- dopamine (DA) - behavior learning, receptors are "D" - serotonin (5-HT) - mood(?), receptors are "5-HT" - acetylcholine (ACh) - attention, receptors are "M" and nicotinic. - norepinephrine (NE) - vigilance, receptors are alpha, beta. - histamine (HIST) - sleep/wake, receptors are "H"

Know the five classifications of receptors in terms of the types of stimuli they respond to.

1) CHEMORECEPTORS: detect the presence of chemicals. 2) THERMORECEPTORS: detect changes in temperature. 3) MECHANORECEPTORS: detect mechanical forces. 4) PHOTORECEPTORS: detect light during vision. 5) NOCICEPTORS: responsible for detecting or responding to pain

Describe the four processes that comprise the body's second line of defense.

1) Natural killer cells. True to their name, natural killer (NK) cells' natural inclination is to kill everything they meet. ... 2) Phagocytes. Cells that engulf - or phagocytose - microbes or other cells that are infected, damaged or dying. ... 3) Inflammation. ... 4) Complement. ...

What are the two classes of hormones and how and where do each of these two classes function?

1) Protein hormones (or polypeptide hormones) are made of chains of amino acids. An example is ADH (antidiuretic hormone) which decreases blood pressure. 2) Steroid hormones are derived from lipids

List the three basic structural forms of bacteria.

1) Round bacteria are referred to as cocci (singular: coccus); 2) cylindrical, capsule-shaped bacteria as bacilli (singular: bacillus); 3) spiral bacteria are aptly called spirilla (singular: spirillum)

What are the three most important functions of the lymphatic system.

1) The removal of excess fluids from body tissues 2) Absorption of fatty acids and subsequent transport of fat, chyle, to the circulatory system. 3) Production of immune cells (such as lymphocytes, monocytes, and antibody producing cells called plasma cells).

What steps can you take to prevent antibiotic resistance?

1) Understand that most of us don't need antibiotics for colds and flu since they're caused by viruses 2) Tell your doctor you only want an antibiotic if it's completely necessary 3) Take the right dose of your antibiotic at the right time, as prescribed by your doctor 4) Only take your antibiotics for as long as your doctor tells you to 5) From always washing your hands with warm soapy water to staying home whenever you're sick, take steps to avoid infections and prevent them from spreading - plus take the pledge to fight antibiotic resistance.

Distinguish between an exteroceptor and interoceptor.

1. Exteroceptors Respond to stimuli arising outside the body Receptors in the skin for touch, pressure, pain, and temperature Most special sense organs 2. Interoceptors (visceroceptors) Respond to stimuli arising in internal viscera and blood vessels Sensitive to chemical changes, tissue stretch, and temperature changes

Understand how receptors receive and convert stimuli into information to be sent to the brain. Differentiate between sensation and perception of a stimulus.

1. The sensory receptors receive stimulation + pass the resulting impulses to the brain in the form of neural impulses. 2. Most sensory information first goes to the thalamus, a structure in the middle of the brain 3. Neurons in the thalamus then send information to the cerebral cortex, where incoming neural impulses are interpreted as sight, sound, taste, smell, or touch. Sensation: stimulation of sensory organs Perception: processing and interpretation of sensory input The two merge when sensory receptors convert physical energy into neural impulses.

Be able to identify characteristics of viruses.

1. They are enclosed in a protective envelope. 2. They have spikes, which helps them to attach to the host cell. 3. They are non cellular. 4. They do not respire, do not metabolize and do not grow but they do reproduce. 5. They contain a protein coat called the capsid. 6. They have a nucleic acid core containing DNA or RNA.

Know the hormones and effects of short term (acute) stress versus long term stress.

Acute stress is short-term stress EX) any stress you suffer from for a short period of time like a traffic jam, an argument with your spouse, an unkind criticism from your boss or someone breaking into your house when you aren't there Chronic stress is long-term stress. individual perceives they have little or no control

What is an allergy? What is an autoimmune disorder? Give some examples.

Allergies occur when the immune system overreacts to ordinarily harmless substances. Allergies are a very common overreaction of the immune system to usually harmless substances. Autoimmune disease: A disease in which the body's immune system attacks healthy cells.

What are the benefits and services of microbes (bacteria and fungi) contribute to ecosystem function, food production and other products, and to our health?

Along with bacteria, fungi are important as decomposers in the soil food web. They convert hard-to-digest organic material into forms that other organisms can use. Fungal hyphae physically bind soil particles together, creating stable aggregates that help increase water infiltration and soil water holding capacity. Although we often think of fungi as organisms that cause disease and rot food, fungi are important to human life on many levels. They influence the well-being of human populations on a large scale because they are part of the nutrient cycle in ecosystems. They also have other ecosystem uses, such as pesticides.

Know the function and two examples of a pair of antagonistic hormones? (I. e. insulin - glucagon)

Antagonistic hormones are actually pairs of hormones that work against each other. As we will see, though insulin and glucogon or PTH and Calcitonin work on the same systems, they are constantly fighting against each other in order to maintain homeostasis. Round One: Insulin and Glucagon Round Two: PTH and Calcitonin

Describe the structure and function of an antibody. How do they inactivate or eliminate antigens from the body? What cells produce antibodies?

Antibodies contribute to immunity: When an antigen enters the body, it stimulates the immune system to produce antibodies. (The immune system is the body's natural defense system.) ... The role of antibodies is to bind with antigens and inactivate them so that other bodily processes can take over, destroy, and remove the foreign substances from the body A lymphocyte is a type of white blood cell that is part of the immune system. There are two main types of lymphocytes: B cells and T cells. The B cells produce antibodies that are used to attack invading bacteria, viruses, and toxins.

Be able to identify characteristics of bacteria. What is binary fission?

Bacteria are like eukaryotic cells in that they have cytoplasm, ribosomes, and a plasma membrane. Features that distinguish a bacterial cell from a eukaryotic cell include the circular DNA of the nucleoid, the lack of membrane-bound organelles, the cell wall of peptidoglycan, and flagella. Binary fission ("division in half") is a kind of asexual reproduction. ... In binary fission, the fully grown parent cell splits into two halves, producing two new cells. After replicating its genetic material, the parent cell divides into two equal sized daughter cells.

What are complement proteins? Explain how they act directly and indirectly to protect the body against disease?

Complement: a complex system of more than 30 proteins that act to eliminate infectious microorganisms Lastly, antibodies can activate a group of proteins called complement that are also part of the immune system. Complement assists in killing bacteria, viruses, or infected cells. All of these specialized cells and parts of the immune system offer the body protection against disease. This protection is called immunity.

What is the resting potential? Explain how a nerve impulse is an electrochemical signal including what changes occur in the membrane upon nerve stimulation?

Def: the electrical potential of a neuron or other excitable cell relative to its surroundings when not stimulated or involved in passage of an impulse Transmission of a nerve impulse: Resting potential and action potential. Like the gaps between the Schwann cells on an insulated axon, a gap called a synapse or synaptic cleft separates the axon of one neuron and the dendrites of the next neuron. The neurotransmitter binds with receptors on the neuron

Understand how pain or nociceptors are stimulated.

Distributed throughout the body (skin, viscera, muscles, joints, meninges) they can be stimulated by mechanical, thermal or chemical stimuli. Inflammatory mediators (eg bradykinin, serotonin, prostaglandins, cytokines, and H+) are released from damaged tissue and can stimulate nociceptors directly.

Know the relative addictiveness of the drugs discussed.

Drug addiction is when you can't stop taking the drug even if you want to. The urge is too strong to control, even if you know the drug is causing harm

Know all of the following endocrine glands and what their function is? Hypothalamus, Pituitary Gland, Thyroid, Parathyroid, Pancreas, Pineal Gland, Adrenal Glands, ovaries, testis, thymus.

Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands.

What is epidemiology?

Epidemiology is the study and analysis of the distribution (who, when, and where) and determinants of health and disease conditions in defined populations. ... Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences.

Explain what causes cataracts, nearsightedness, farsightedness, astigmatism, and color blindness.

Farsightedness, or hyperopia, is caused when the curvature of the cornea is too flat or the eyeball is too short, forcing light to focus behind the retina. With farsightedness, the eye's weak refractive power causes far objects to be seen more clearly and near objects to appear blurred. It's not known what causes astigmatism, but genetics is a big factor. It's often present at birth, but it may develop later in life. It may also occur as a result of an injury to the eye or after eye surgery. Astigmatism often occurs with nearsightedness or farsightedness.

Describe the reflex arc that occurs when you have stepped on something sharp (withdrawal reflex).

For example, consider what happens when you step on a sharp object. As in the example above, a sensory (pain) neuron carries an impulse to an interneuron in the spinal cord. The interneuron synapses with motor neurons which pull your foot away from the sharp object, just as in the example above.

Differentiate between the general senses and the five special senses.

General: throughout the body Special: more specialized and complex (hearing, sight, balance, taste, smell) General: detect touch, pain pressure, temperature, and tension on the skin and in internal organs Special senses: detect the sensations of taste, smell, hearing, equilibrium, and sight

What are the major processes controlled by hormones in the body?

Growth and development Homeostasis (the internal balance of body systems) Metabolism (body energy levels) Reproduction Response to stimuli (stress and/or injury)

Know which of the hormone types elicits a response from its target cell by binding to a cell membrane-bound receptor.

Hormones with Cell Surface Receptors. Protein and peptide hormones, catecholamines like epinephrine, and eicosanoids such as prostaglandins find their receptors decorating the plasma membrane of target cells

Describe the structure and location of taste buds and taste cells. Explain how taste is perceived and identify the four primary regions of taste on the tongue.

Humans have taste receptors on taste buds (gustatory calyculi) and other areas including the upper surface of the tongue and the epiglottis. ... Each taste bud contains 50 to 100 taste receptor cells. The sensation of taste includes five established basic tastes: sweetness, sourness, saltiness, bitterness, and umami.

How is it that we can get the influenza virus again and again?

If you're wondering whether you can get the flu twice in one season, bad news: experts say yes, you can. ... Because there are multiple strains of the flu, and the flu vaccine is only 30 percent effective this year — and it doesn't protect you against every strain — you can get the flu multiple times. You can certainly contract the flu more than once a year, because there are many different strains of the influenza virus. ... It is possible that you could get infected with one strain and then another during a given season, especially if you have a compromised immune system.

Explain the roles of the myelin sheath. How does myelination influence the speed?

Most nerve fibres are surrounded by an insulating, fatty sheath called myelin, which acts to speed up impulses. The myelin sheath contains periodic breaks called nodes of Ranvier. By jumping from node to node, the impulse can travel much more quickly than if it had to travel along the entire length of the nerve fibre

Explain why different individuals may experience different levels of intoxication having had the same amount of alcohol. Recognize the effects of alcohol on the various body systems, nutrition, cancer, and fetal development.

Nearly everything that enters your body will be shared with your baby. The risks associated with drug use during pregnancy depend on various factors...can affect the development of your baby's central nervous system.

The following statement is a MISCONCEPTION: The endocrine system and nervous system are two separate systems that regulate physiology and homeostasis. Know why is that statement is wrong?

Nervous & endocrine systems work together to maintain homeostasis of the body The nervous system controls virtually all body activities, and the endocrine system secretes hormones that regulate these activities.

How is the nervous system different from the endocrine System?

Nervous system uses electrical impulses to send signals through neurones, whereas endocrine system uses chemical messengers transported into blood plasma to target cells (this means communication's faster when using the nervous system)

Differentiate between a neuron and glial cells in structure and function. Label the parts of a generalized neuron.

Neurons have TWO "processes" called axons and dendrites Glial cells have only ONE process Neurons CAN generate action potentials glial cells CANNOT generate Neurons HAVE synapses that use neurotransmitters glial cells do NOT have chemical synapses

Which type of sensory receptor CANNOT adapt (sensory adaptation) to a particular sensation?

Pain, joint and muscle monitoring receptors do not adapt. They help protect the body from damage or further injury.

What is the body's third line of defense against disease?

Pathogens contain certain chemicals that are foreign to the body and are called antigens. White blood cells called lymphocytes carry a specific type of antibody - a protein that has a chemical 'fit' to a certain antigen.

What type of receptor found in the muscular system enables the brain to perceive body position?

Proprioceptors: sensory receptors located in the inner ear, muscles, tendons, and joints that use internal stimuli to detect changes in position/ movement of the body or its limbs

Recognize characteristics of protozoans. Give an example of a disease caused by a protozoan.

Protozoa are eukaryotic microorganisms. Although they are often studied in zoology courses, they are considered part of the microbial world because they are unicellular and microscopic. Protozoa are notable for their ability to move independently, a characteristic found in the majority of species. EX) Protozoan infections: parasitic diseases caused by organisms formerly classified in the Kingdom Protozoa. They include organisms classified in Amoebozoa, Excavata, and Chromalveolata. Examples include Entamoeba histolytica, Plasmodium (some of which cause malaria), and Giardia lamblia.

Compare and contrast the rods and the cones.

Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. Cones are of three types of photoreceptor cells in the retina of mammalian eyes (e.g. the human eye). They are responsible for color vision and function best in relatively bright light, as opposed to rod cells, which work better in dim light.

Differentiate between rotational equilibrium and gravitational equilibrium.

Rotational: muscles move (rotationally and angularly) as needed to keep balance from sensory input. Gravitational: mechanoreceptors, vision, and proprioceptors work together. Only moves horizontally and vertically.

What is meant by sensory or receptor adaptation. Given an example.

Sensory adaptation: a change over time in the responsiveness of the sensory system to a constant stimulus. Depending on the stimulus, receptors may increase or decrease their ability to respond, and will develop an enhanced or diminished sensitivity to the stimulus

What are the immediate effects of alcohol consumption and what are the long term effects of alcohol abuse?

Short-term effects of alcohol include: memory Problems walking Slurred speech Blurry vision Impaired reaction time Reduced inhibitions Long-term: weight gain. Problems with coordination. Nerve damage. Inflammation of the liver (alcoholic hepatitis). Scarring of the liver (cirrhosis). Cancer of the liver. Increase blood pressure. Damage of the heart muscle (alcoholic cardiomyopathy). Disruption of the healthy growth of new brain cells.

Describe an example of negative feedback in human physiology.

Some biological systems exhibit negative feedback such as the baroreflex in blood pressure regulation and erythropoiesis. Many biological process (e.g., in the human anatomy) use negative feedback. Examples of this are numerous, from the regulating of body temperature, to the regulating of blood glucose level

What are the ways in which drugs can interfere with neurotransmission?

Some drugs primarily affect one neurotransmitter or class of neurotransmitters. For example, nicotine stimulates cells directly by activating their receptors for acetylcholine, and indirectly by inducing higher levels of glutamate, a neurotransmitter that acts as an accelerator for neuron activity throughout the brain

What are the five neurotransmitters and are they mostly excitatory or inhibitory?

Some of the major inhibitory neurotransmitters include serotonin and gamma-aminobutyric acid (GABA). Some neurotransmitters, such as acetylcholine and dopamine, can create both excitatory and inhibitory effects depending upon the type of receptors that are present

Why is it that we do not need to worry about permanently losing our sense of taste if we burn our tongue?

Taste buds go through a life cycle where they grow from basal cells into taste cells and then die and are sloughed away. According to Dr. Bartoshuk, their normal life cycle is anywhere from 10 days to two weeks. However, "burning your tongue on hot foods can also kill taste buds"

Know the functions of the blood brain barrier (BBB). Recognize which types of substances can and cannot cross the BBB.

The BBB has several important functions: Protects the brain from "foreign substances" in the blood that may injure the brain. Protects the brain from hormones and neurotransmitters in the rest of the body. Maintains a constant environment for the brain Large molecules do not pass through the BBB easily. Low lipid (fat) soluble molecules do not penetrate into the brain. However, lipid soluble molecules, such as barbituate drugs, rapidly cross through into the brain. Molecules that have a high electrical charge are slowed

What are the different groups of agents that cause disease?

The agents that cause disease fall into five groups: viruses, bacteria, fungi, protozoa, and helminths (worms)

Be able to identify the functions of the medulla oblongata, pons, cerebellum, midbrain, and diencephalon (thalamus and hypothalamus).

The brain stem serves multiple functions, but its main function is to regulate the autonomic, most fundamental functions of the brain—regulating heart rate, controlling reflexes, breathing, and consciousness. This is accomplished through the brain stem's 3 regions: the Midbrain, the Pons, and the Medulla Oblongata

Describe multiple sclerosis and its cause.

The cause of multiple sclerosis is unknown. It's considered an autoimmune disease in which the body's immune system attacks its own tissues. In the case of MS, this immune system malfunction destroys myelin (the fatty substance that coats and protects nerve fibers in the brain and spinal cord)

Identify the two main parts of the nervous system and its components.

The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

Explain the location and functions of the primary sensory and motor areas of the cerebral cortex.

The cerebral cortex is divided into sensory, motor and association areas. Sensory areas receive sensory input, motor areas control movement of muscles. Association areas are involved with more complex functions such as learning, decision making and complex movements such as writing

Describe the structure and functions of the cerebrum and recognize the functional areas of the lobes of the cerebral cortex.

The cerebrum is the major structure in the brain, composed of a right and left hemisphere. Each hemisphere works together to control both sides of the body. Within the hemispheres are regions we call lobes. The four lobes include the occipital, temporal, frontal, and parietal lobes.

What are the two overall functions of the ear?

The ears are organs that provide two main functions — hearing and balance — that depend on specialized receptors called hair cells.

Know the general purpose (function) and properties of the endocrine system.

The endocrine system is the collection of glands that produce hormones that regulate metabolism, growth and development, tissue function hypothalamus. pituitary gland. thyroid. parathyroids. adrenal glands. pineal body. reproductive glands (which include the ovaries and testes) pancreas

Recognize the chemical and physical barriers that prevent the entry of pathogens into the body. What is the body's most important barrier?

The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils. The skin is the most important mechanical barrier. In fact, it is the single most important defense that the body has against pathogens. It forms a physical barrier between the body and the outside world

Signs of inflammation include redness, warmth, swelling, and pain. What causes these symptoms? How does inflammation help defend against infection?

The four cardinal signs of inflammation are redness (Latin rubor), heat (calor), swelling (tumor), and pain (dolor). Redness is caused by the dilation of small blood vessels in the area of injury These cells help to fight infection in your body. White blood cells, also known as leukocytes, are the cells of the immune system. White blood cells help fight infection by attacking invaders and consuming infected or dead cells. ... Lymphocytes are a special type of white blood cell.

Understand the significance and function of major compatibility complex (MHC) proteins.

The function of MHC molecules is to bind peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate T cells The importance of MHC proteins is that they allow T cells to distinguish self from non-self.

Distinguish between antibody-medicated immunity and cell-mediated immunity and the types of cells involved in each mechanism of defense. What are the targets of each type of immunity?

The humoral immunity is mediated by B cells. ... Cell Mediated Immunity: The TCR receptors are involved in the cell mediated immunity.

What types of defensive cells play a role in the body's nonspecific defense mechanisms? Know the targets of each and how it kills them.

The immune system consists of cells and tissues found throughout the body. The body uses both nonspecific and specific defense mechanisms to detect and destroy pathogens, thereby preventing or reducing the severity of infection. The body's surface defenses are nonspecific, meaning they do not target specific pathogens

Know the structures of the ear involved in maintaining equilibrium and balance.

The information about the dynamic equilibrium is detected in the semicircular canals which are attached to the vestibule. The inner ear (also called the labyrinth) contains 2 main structures — the cochlea, which is involved in hearing, and the vestibular system (consisting of the 3 semicircular canals, saccule and utricle), which is responsible for maintaining balance. ... It helps dampen the vibrations in the cochlea

Recognize the limbic system and describe its functions.

The limbic system is the portion of the brain that deals with three key functions: emotions, memories and arousal (or stimulation). This system is composed of several parts, which are found above the brainstem and within the cerebrum. The limbic system connects parts of the brain that deal with high and low functions.

What are steroid hormones are synthesized from?

The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids

List the divisions of the peripheral nervous system and be able to identify their components and functions.

The nervous system has two major divisions: central and peripheral. But the peripheral nervous system is further subdivided into the somatic and autonomic nervous system, and the autonomic nervous system is also divided into sympathetic and parasympathetic fibers. The peripheral nervous system is divided into two major parts: the somatic nervous system and the autonomic nervous system.

Describe two functions of the reticular activating system.

The reticular activating system is an impressive-sounding name for a fairly small piece of the brain. This lesson describes the structure and function of this piece of the brain, which is important in attention, goal-achievement, and keeping you alive

Describe how odor is perceived by the chemoreceptors in the nasal cavity. Understand the reason for the association between odors and our emotions and memories.

The sense of smell is closely linked with memory, probably more so than any of our other senses. Those with full olfactory function may be able to think of smells that evoke particular memories; the scent of an orchard in blossom conjuring up recollections of a childhood picnic, for example.

Compare the sympathetic and parasympathetic nervous systems.

The sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. The parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

Describe and give examples of the types of sensory receptors found in the skin.

The types of sensory receptors according to location include cutaneous receptors and mechanoreceptors. Sensory receptors located in the dermis or epidermis of the skin are called cutaneous receptors. These include nociceptors and thermoreceptors.

Describe the various modes of disease transmission. Which is the most common means of transmission of the common cold?

There are four types of contact transmission. 1) Direct—requires physical contact between hosts. 2) Indirect—contact with body fluids or tissues of an infected individual. 3) Droplet—large infectious particles sprayed into the air from the respiratory tract of an infected individual. 4) Droplet nuclei—small infective particles that are suspended in the air, taken in by a host, and are capable of traveling to the lung. Although many types of viruses can cause a common cold, rhinoviruses are the most common culprit. A cold virus enters your body through your mouth, eyes or nose. The virus can spread through droplets in the air when someone who is sick coughs, sneezes or talks

What are the three types of neurons based on function and what is their relationship to the CNS?

There are three types of neurons in the nervous system - afferent, efferent and interneurons. Afferent neurons carry signals towards the CNS - afferent means "towards". They provide information about the external environment and the regulatory functions being carried out by the nervous system the brain needs all of them to communicate effectively with the rest of the body

Which type of hormones can cross cell membranes and elicit their response through stimulating protein synthesis?

These forms of hormones are lipids. They can pass through the cell membrane as they are fat-soluble, and then bind to steroid hormone receptors (which may be nuclear or cytosolic depending on the steroid hormone) to bring about changes within the cell.

Describe each of the general or somatic senses and give examples of their locations in the body. Know where in the cerebral cortex impulses from sensory neurons linked to these receptors are sent.

These nerves send signals between the brain, spinal cord, and other body organs via nerve impulses. Neurons are classified as either motor, sensory, or interneurons. Motor neurons carry information from the central nervous system to organs, glands, and muscles

How do hormones released from endocrine glands get to their targets?

They circulate through the bloodstream, bind to target cells, and adjust the function of whole tissues and organs. ... The hormones they release control the secretions of the other endocrine glands and most endocrine functions. Hormones travel throughout the body, either in the blood stream or in the fluid around cells, looking for target cells

Describe how a vaccine produces immunity from a specific disease.

Vaccines are like a training course for the immune system. They prepare the body to fight disease without exposing it to disease symptoms. When foreign invaders such as bacteria or viruses enter the body, immune cells called lymphocytes respond by producing antibodies, which are protein molecules.

Explain the phenomenon of referred pain. Why is pain important?

When there is an important stimulus of the lower sensory input the brain can interpreted this as coming from the higher regions. Because the brain is not used to this important input of the lower regions. So the pain well be located in the related dermatome of the same spinal segment. Sometimes pain felt in one area of the body does not accurately represent where the problem is because the pain is referred there from another area. Pain can be referred because signals from several areas of the body often travel through the same nerve pathways in the spinal cord and brain.

What are two fundamental differences between taste and smell?

When you eat something, you can tell the difference between sweet and bitter. It is the sense of smell that is used to distinguish the difference. Although humans commonly distinguish taste as one sense and smell as another, they work together to create the perception of flavor

How is mild fever beneficial in fighting an infection? What happens if our body temperature rises over 105 degrees F and why?

With cold and flu season almost here, the next time you're sick, you may want to thank your fever for helping fight off infection. That's because scientists have found more evidence that elevated body temperature helps certain types of immune cells to work better. A higher body temperature accelerates the internal workings of cells. This means disease-fighting cells respond faster, and immune responses increase. Germs, on the other hand, don't reproduce as well at higher temperatures. A very high fever can slow down or kill off the microbes that cause some infectious diseases. A body temperature of 104 degrees indicates danger, 105 degrees is in the definition of heat stroke and a temperature of 107 degrees could result in irreversible organ damage or death.

Know why nicotine is so addictive.

Yes. Most smokers use tobacco regularly because they are addicted to nicotine. Addiction is characterized by compulsive drug-seeking and use, even in the face of negative health consequences. The pharmacokinetic properties of nicotine contribute to its addictiveness. When cigarette smoke enters the lungs, nicotine is absorbed rapidly in the blood and delivered quickly to the brain, so that nicotine levels peak within 10 seconds of inhalation. this rapid cycle causes the smoker to continue dosing to maintain the drug's pleasurable effects and prevent withdrawal symptoms

What are some effects of marijuana? What are some of its medicinal uses.

altered senses (for example, seeing brighter colors) altered sense of time changes in mood impaired body movement difficulty with thinking and problem-solving impaired memory hallucinations (when taken in high doses) delusions (when taken in high doses) contains pain relieving properties

What is an antibiotic? What is antibiotic resistance and why is it of great public health importance?

antibiotic: Antimicrobial agent made from microorganisms, and can kill and inhibit the growth of microorganisms, especially those that are infectious or disease-causing Antimicrobial resistance is a public health threat driven by healthcare practices, most notably the overuse of antimicrobials in conditions for which they provide no benefit. Resistance is a characteristic of many pathogens causing different diseases. They are able to survive and even multiply in the presence of an antibiotic. Most infection-causing bacteria can become resistant to at least some antibiotics. Bacteria that are resistant to many antibiotics are known as multi-resistant organisms (MRO) Antibiotic resistance occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply causing more harm. ... Antibiotics kill or inhibit the growth of susceptible bacteria

What are the immediate effects of stimulants like cocaine and methamphetamines use and what are the long term effects of stimulants abuse on fetuses and adults?

increased rates of premature delivery, placental abruption (separation of the placental lining from the uterus), and various effects on babies prenatally exposed to methamphetamine, including small size, lethargy, and heart and brain abnormalities neurobehavioral problems such as decreased arousal and increased stress and subtle but significant attention impairments in these children.

Describe the mechanisms of action of drugs and differentiate between tolerance and physical dependence (addiction).

mechanism of action (MOA) refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targets to which the drug binds, such as an enzyme or receptor Drug tolerance has to do with how effective a particular dose of a particular drug is in a particular person. With some drugs, tolerance can build over time. Drug dependence is a physical phenomenon. It simply means that if a person takes a drug for a period of time and then stops taking it abruptly or suddenly lowers the dosage, he or she will experience physical symptoms, which may range from annoying to serious.

Understand what positive feedback and negative feedback are and how they help to maintain homeostasis.

positive feedback amplifies change while negative feedback reduces change. This means that positive feedback will result in more of a product: more apples, more contractions, or more clotting platelets Unlike negative feedback that maintains hormone levels within narrow ranges, positive feedback is rarely used to maintain homeostatic functions. An example of positive feedback can be found in childbirth. The hormone oxytocin stimulates and enhances labor contractions.

Describe the structure and function of the spinal cord. Distinguish between the cranial and spinal nerves.

spinal cord: connects a large part of the peripheral nervous system to the brain. Information (nerve impulses) reaching the spinal cord through sensory neurons are transmitted up into the brain Cranial = nerves originate from the brain Spinal = nerves originate from the spinal cord

What are the body's three lines of defense against disease? Explain the difference between nonspecific and specific defense mechanisms.

the first is to keep invaders out (through skin, mucus membranes, etc), the second line of defense consists of non-specific ways to defend against pathogens that have broken through the first line of defense (such as with inflammatory response and fever). The third line of defense is mounted against specific pathogens that are causing disease The main difference between specific and nonspecific immune response is that specific immune response protects the body against specific pathogens whereas nonspecific immune response is the same for all pathogens.

Define virulence.

virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism - its ability to cause disease - is determined by its virulence factors