Chapter 11, 16, 18, 21 Questions

Cl−Cl− is a common, negatively charged extracellular ion. Predict the effect on the RMP if many Cl−Cl− gated channels are suddenly opened.

A more negative RMP would result. Submit

Which of the following is true of axons?

A neuron can have only one axon, but the axon may have occasional branches along its length.

Which of the following hormone pairs exhibit an antagonistic relationship?

Angiotensin II & ANP

Adult onset diabetes, diabetes type 2, can best be described using which of the following concepts?

Constantly high blood sugar leads to high insulin release. High amounts of insulin lead to down-regulation of insulin receptors.

What type of conduction takes place in unmyelinated axons?

Continuous conduction

Which of the following adrenal gland homeostatic imbalances is characterized by persistent elevated blood glucose levels, dramatic losses in muscle and bone protein, and water and salt retention, leading to hypertension and edema?

Cushing's syndrome

Which description of synapses is not correct?

Direct signaling involves the activation of G proteins.

How do endocrine hormones reach their target cells?

Hormones are transported through the blood stream to target cells.

People with multiple sclerosis (MS) experience many challenging symptoms. Which statement best explains one cause of these difficulties?

Loss of oligodendrocytes in the central nervous system results in absence of the myelin sheath of neuronal axons, impairing rapid saltatory conduction.

In which type of axon will velocity of action potential conduction be the fastest?

Myelinated axons with the largest diameter

The concentrations of which two ions are highest outside the cell?

Na+ and Cl−

Which of the following is a hormone produced by the posterior pituitary?

None of the listed responses is correct. Submit

Which of the following does NOT describe the process of summation?

One EPSP fails to bring the cell to threshold.

What is the role of activated protein kinases?

Phosphorylate proteins.

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS?

Schwann cells

Which of the following statements is correct regarding the polarization of a neuronal membrane and the formation of a resting membrane potential?

Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels.

In a lab you are conducting tests with various chemicals and neurotransmitter receptors. You notice that exposed frog muscle cells depolarize when you add the chemical nicotine to the acetylcholine (ACh) receptors. What does this tell us about the relationship between neurotransmitters and their receptors?

The effect of a neurotransmitter is based on the properties of the receptor more than the neurotransmitter.

Match these prefixes to their meanings.

The prefix neuro- means "pertaining to the nervous system." The prefix endo- means "within." The prefix hyper- means "higher than normal." The prefix de- means "do the opposite of or reverse." The prefix peri- means "around" or "surrounding." The prefix syn- means "being together" or "similar."

Which mechanism allows the rabies virus to gain access to the central nervous system (CNS)?

The rabies virus uses retrograde movement along the neuronal axon.

What is the basic condition when a neuron is described as polarized?

There is a separation of positive and negative charges across a membrane.

Which of the following is NOT representative of endocrine glands?

They use ducts to secrete their products into the surrounding tissue fluid.

Cold sores on the skin of the mouth occur when herpes simplex viruses that are dormant in neural ganglia become active and travel to the skin of the mouth. Which of the following is the mechanism by which these viruses travel from the ganglia (located within the head) to the skin of the mouth?

anterograde transport

Which hormone aids in water resorption?

antidiuretic hormone

Which of the following hormones helps the body avoid dehydration?

antidiuretic hormone

Which glial cells have the most diversity of function?

astrocytes

Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon?

degree of myelination of the axon Submit

Which of the following events would be directly affected if a neuron had a mutation that prevented the production of voltage-gated Na+ channels?

depolarization leading to action potentials

An action potential is self-regenerating because __________.

depolarizing currents established by the influx of Na+‎ flow down the axon and trigger an action potential at the next segment

Which of the following is not a major type of stimulus that triggers endocrine glands to manufacture and release hormones?

enzymatic

Which of the following hormones has significantly different effects when it is released in males instead of females?

follicle-stimulating hormone

Which pancreatic hormone functions to raise blood glucose levels?

glucagon

What is directly required for the production of anterior pituitary gland hormones?

hormonal stimuli

Complete the following sentence. The operation of the Na+−K+Na+−K+ ATPase pump __________.

moves 3 Na+Na+ to the ECF and 2 K+K+ to the cytoplasm

A molecule that carries information across a synaptic cleft is a

neurotransmitter.

Which of the following is NOT a type of circuit?

pre-synaptic circuits

What division of the nervous system is most specifically responsible for voluntary motor control?

somatic nervous system

The small space between the sending neuron and the receiving neuron is the

synaptic cleft.

Which of the following occurs in situations where different hormones produce the same effects at the same target cell and their combined effects are amplified?

synergism

Which is the main receptive portion of the neuron?

the dendrite

Which criterion is used to functionally classify neurons?

the direction in which the nerve impulse travels relative to the central nervous system Submit

When calcium ions enter the synaptic terminal,

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron. Submit

Which choice best characterizes K+ leakage channels?

transmembrane protein channels that are always open to allow K+K+ to cross the membrane without the additional input of energy

Which of the following pairs correctly matches the adrenal gland structure with the class of hormones it produces?

zona glomerulosa: mineralocorticoids Submit

Your patient is living with HIV infection and has not developed AIDS. She knows that her CD4 count is carefully monitored, and she asks why this test is important. How would you explain the role of CD4 cells?

"CD4 cells are special lymphocytes (white blood cells) that activate other immune cells and direct your body's response to invaders."

Your patient has been diagnosed with Type I diabetes mellitus, and you are explaining how to administer insulin. Your patient states, "I don't want to do this. My brother-in-law has diabetes, and he just takes a pill and watches what he eats." What is your best response?

"Your relative may have Type II diabetes. People with that condition can make insulin, but their cells don't respond to it properly. Your pancreas doesn't manufacture insulin."

Assume you have a membrane with only potassium leakage channels. The RMP is -90mV. Predict the RMP if we add Na+Na+ leakage channels.The most likely RMP value of Na+Na+ is __________.

-70 mV

Match the cardiac components in the left column to the blanks near their functions on the right.

1. AV bundle : Electrical link(s) between atria and ventricles 2. Purkinje fibers: Convey(s) the impulse throughout the ventricular walls 3. SA node: Set(s) the pace for the entire heart 4. Internodal pathways: Link(s) between the SA node and AV node 5. Bundle branches: Convey(s) the impulse down the interventricular septum 6. AV node: Delay(s) occurs here while atria contract

Match the term in the left column to the blanks near their definition on the right.

1. End diastolic volume (EDV): the volume of blood in one ventricle before contraction 2. Venous return (VR): the volume of blood per minute flowing into one atrium 3. Cardiac output (CO): the volume of blood per minute pumped out by one ventricle 4. End systolic volume (ESV): the volume of blood in one ventricle after contraction 5. Stroke volume (SV): the volume of blood per heart beat pumped out by one ventricle 6. Heart rate (HR): the number of heart beats per minute

Drag and drop the terms to the appropriate blanks in the sentences on the right. Not all labels are used.

1. The structure that prevents backflow of blood into the left atrium is the mitral (bicuspid) valve. 2. The vessel that carries oxygen-rich blood to tissues is the aorta. 3. The capillaries receiving blood flow from the left side of the heart are the systemic capillaries. 4. The structure that is located anatomically between the aorta and the left ventricle is the aortic semilunar valve.

Drag and drop the correct item name to complete each sentence.Terms may be used more than once or not at all.

1. The superior vena cava carries oxygen-poor venous blood from above the diaphragm from areas of the upper body and extremities into the right atrium. 2. The coronary sinus carries oxygen-poor venous blood of the coronary circulation into the right atrium. 3. The inferior vena cava carries oxygen-poor venous blood from below the diaphragm from the areas of the lower body and extremities into the right atrium.

Place the following steps of phagocytosis in the order that they occur: Endosome fuses with lysozome Dendritic cell engulfs Rhinovirus Epitopes are attached to MHC-II Digestion of the Rhinovirus MHC-II plus the attached epitope move to the outside of the dendritic cell

2,1,4,3,5

Correctly order the steps involved cellular immunity: The Tc recognizes the infected host cell The Tc interacts with epitope presented by MHC-I on the dendritic cell The Tc secretes perforin and granzyme, causing apoptosis The helper T cell activates the Tc cell

2,4,1,3

Calculate the stroke volume if the end diastolic volume (EDV) is 135 mL/beat and the end systolic volume (ESV) is 60 mL/beat.

75 mL/beat

Calculate the cardiac output if heart rate (HR) is 90 beats per minute, stroke volume (SV) is 110 ml/beatml/beat, end diastolic volume (EDV) is 140 mlml, and end systolic volume (ESV) is 30 mlml.

9.9 L/min

Which of these conditions would promote aldosterone release from the adrenal glands?

A drop in blood pressure is sensed in the kidney. Submit

Which of the following statements regarding the primary versus the secondary immune response is true?

A primary response results when naïve lymphocytes are activated, while a secondary response is a result of activating memory cells.

What is the ligamentum arteriosum?

A remnant of the ductus arteriosus

Which of the following structures receives the depolarization wave from the atria and passes impulses onto the ventricles?

AV node

Which of these structures conduct(s) action potentials the slowest?

AV node

Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?

AV node

Increased pressure in the ventricles would close what valve(s)?

AV valves only Submit

Which of the following is NOT a step that ultimately leads to antibody production?

Activation of cytotoxic T cells by helper T cells

Which of the following statements is true?

Adaptive defenses include both humoral and cellular immunity.

Hypocalcemia could be caused by the ______.

All of the listed responses are correct. Submit

What is meant by the clonal expansion of a B cell?

An activated B cell divides into cells that give rise to memory B cells and plasma cells.

A class I MHC protein presents an antigen. What type of cell is likely presenting and to what type of cell would it be presented?

Any nucleated cell would present antigens to a CD8 cell.

Which best describe the isovolumetric contraction phase of the cardiac cycle?

As ventricular systole starts, the AV valves are closed and the semilunar valves are closed. Because the ventricles are contracting and both valves are closed, pressure increases rapidly leading to ejection.

Identify the ear like flaps that are attached to the top chambers of the heart.

Auricle

Which pair of molecules do NOT directly interact with one another?

BCR and TCR

Identify the valve found between the left atrium and left ventricle.

Bicuspid (mitral) valve

Select the correct partial path. This path is part of the complete blood flow pathway. You should be able to trace flow starting in any location.

Blood moves from the aorta, through smaller systemic arteries, and into systemic capillaries. From there it moves through systemic veins, into the right atrium, and through the tricuspid valve. Submit

Where are the hormones oxytocin and antidiuretic hormone (ADH) stored?

C

Class I MHC proteins are recognized by which of the following cell types (that are destined to become T cells)?

CD8

Which major class of lymphocytes become cytotoxic T cells?

CD8 cells

Which of the following is NOT a difference between cardiac and skeletal muscle?

Cardiac muscle does not use the sliding filament mechanism for contraction; skeletal muscle does.

Match these vocabulary terms to their meanings.

Chemicals like bacterial toxins that poison cells are described as being cytotoxic. When a cell eats, and the "food" joins with a lysosome prior to digestion, a phagolysosome is formed. MHC, or major histocompatibility complex, proteins are responsible for displaying antigens to immune cells. When antibodies block all binding sites on a virus, neutralization has occurred. The proteins secreted by B cells are called antibodies or immunoglobulins.

What fibrous structure functions to anchor the atrioventricular valves in a closed position?

Chordae tendineae

A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count?

Clonal selection of B cells

Which of the following can be heard with a stethoscope most easily?

Closing of atrioventricular valves

Cancer cells would be attacked by which of the following cells?

Cytotoxic T cells

Which letter represents the hormone that promotes a decrease in blood pressure and increases the excretion of sodium and water in urine?

D

These activities change heart rate by changing the balance of parasympathetic and sympathetic stimulation of the heart. Sort each of the activities according to whether it decreases or increases heart rate. Drag the appropriate items to their respective bins.

Decreases heart rate Lying down Digesting a meal Increases heart rate Standing up Fright or anger Exercise

Name the inner lining of the heart.

Endocardium

People who have hydrocephaly often have an issue with which of these glial cell types?

Ependymal cells

More Na+ than K+ leaks through neuron membranes because of the properties of the non-gated leak channels.

False

Oxygenated blood flows through the right side of the heart.

False

Second messenger signaling systems produce small but rapid target cell effects.

False

Steroid hormones are synthesized from amino acids.

False

The base of the heart is located at the bottom of the heart.

False

The hypothalamus is known to control the activity of the thyroid, which has traditionally been called the master endocrine gland.

False

The moderator band is found on both the right and left side of the heart.

False

Up-regulation involves the loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.

False

Water-soluble hormones are inactivated and removed from the blood by the liver.

False

Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones?

GH (growth hormone)

What is the role of helper T cells in the adaptive immune response?

Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.

Damage of which of the following brain structures could cause central diabetes insipidus?

Hypothalamus

Which of the following are properly matched?

IgG: most abundant antibody

What changes occur to voltage-gated Na+ and K+ channels at the peak of depolarization?

Inactivation gates of voltage-gated Na+‎ channels close, while activation gates of voltage-gated K+‎ channels open.

Which of the following statements does not describe the adaptive immune response?

It occurs immediately after the body is challenged by foreign material.

Identify the most muscular chamber.

Left ventricle

What heart chamber pushes blood through the aortic semilunar valve?

Left ventricle

Drag and drop the terms to arrange them, from left to right, in order of blood flow of oxygen-rich blood into the heart.

Lung capillaries Pulmonary veins Left atrium Mitral/bicuspid valve Left ventricle Aortic/semilunar valve

Match the words in the left column to the appropriate phrases on the right. Make certain each word is matched with a phrase before submitting your answer.

Membrane potential of −−70 mVmV Membrane potential of −70 m V: The resting membrane potential of the cell : The resting membrane potential of the cell K+K+ permeability K + permeability: The primary determinant of the resting membrane potential : The primary determinant of the resting membrane potential Na+Na+ permeability N a + permeability: Although it plays a role, it is not a primary determinant of the resting membrane potential : Although it plays a role, it is not a primary determinant of the resting membrane potential Membrane potential of −−90 mVmV Membrane potential of −90 m V: The point at which there is no net movement of K + into or out of the cell : The point at which there is no net movement of K+K+ into or out of the cell

The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again?

Memory B cells

For each of the following, indicate whether the condition will cause the membrane potential to become more positive, more negative, or largely unchanged when compared to the normal physiological resting membrane potential. Drag the appropriate items to their respective bins.

More Positive Triple the number of Na+Na+ leak channels Double the concentration of K+K+ outside the cell More Negative Double the number of K+K+ leak channels Decrease the concentration of Na+Na+ outside the cell by half Largely Unchanged Double the size of the cell, without adding channels Double the number of closed channels for K+K+

Which of the following is correct about the filling of the ventricles?

Most blood flows passively into the ventricles through open AV valves. Submit

Which statement regarding cardiac muscle structure is accurate?

Myofibrils of cardiac muscle tissue vary in diameter and branch extensively.

Which of the following does NOT describe conditions that occur during an action potential?

Na+ is used to repolarize the membrane.

A recent measles outbreak in your community has sparked interest in antibody testing to determine which patients are immune, which are at risk for infection, and which patients actually have measles. Which patient status and lab values are incorrectly matched?

Never immunized and ill with measles for 3 days: IgG +/ IgM -

Match these vocabulary terms to their meanings.

Overeating, or polyphagia, is a sign associated with diabetes mellitus. Upon the release of renin, angiotensin II is produced and stimulates vasoconstriction and the release of aldosterone. An enzyme that degrades second messengers like cAMP or cGMP is phosphodiesterase. FSH and LH are examples of gonadotropic hormones, which target the ovaries or testes. Overproduction of urine, or polyuria, is a sign of diabetes mellitus.

Sort the terms into the appropriate category of either oxygen-poor or oxygen-rich.

Oxygen-Poor Superior vena cava Right atrium Right ventricle Pulmonary arteries Oxygen-Rich Aorta Left ventricle Left atrium Pulmonary veins

Contraction of the atria results from which wave of depolarization on the ECG tracing?

P wave

A patient is being treated by her urologist for a fourth episode of kidney stones. Analysis of the stones shows that they are composed of calcium oxalate. The urologist orders an assay of which hormone?

Parathyroid hormone (PTH)

Name the ridged bundles of muscle found projecting inside the right atrium.

Pectinate muscles

As your skeletal muscles contract during physical activity, more blood is returned to the heart. Which variable would be affected and what would be the outcome of this action?

Preload would be increased, which would result in a larger cardiac output.

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.

Pressure in the atria would be greater than the pressure in the ventricles.

What is the function of the coronary circulation?

Provide a blood supply to the heart

Your patient has been diagnosed with right ventricular failure. Which of the following abnormalities is not a direct result of this problem?

Pulmonary edema (fluid in the alveoli)

Identify the valve located at the exit of the right ventricle.

Pulmonary semilunar valve

A person notices his or her heart beat because he or she senses blood being pumped by the heart. Excessive caffeine intake can lead to irregular heart rhythms (arrhythmias) that patients perceive as "skipped beats." Given that caffeine is a stimulant, which of the following mechanisms best explains the reason for the feeling that the heart skipped a beat?

Purkinje fibers initiate spontaneous action potentials, which cause the ventricles to contract early. Submit

Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells?

Recognition of infected host cell using its CD4 glycoprotein

Which of the following is NOT one of the basic functions of the nervous system?

Release hormones into the bloodstream that travel around the systemic blood circulation to communicate with cells in multiple locations within the body.

Which chamber of the heart exits into the pulmonary trunk?

Right ventricle

Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?

SA node

Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?

SA node

Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat. Rank from first to last. Do not overlap any tiles.

SA node Internodal pathways AV node AV bundle Bundle branches Purkinje fibers

Electrical impulses pass through the conduction system of the heart in the following sequence:

SA node, AV node, bundle of His, bundle branches, and Purkinje fibers

Your patient has been admitted to the intensive care unit with a severe head injury. As you monitor his urine output, you find that it has fallen sharply. Lab tests indicate that his serum osmolality is lower than normal (i.e., his plasma is too dilute). What should you suspect?

Syndrome of inappropriate antidiuretic hormone (SIADH)

Which of the following is/are the most specific internal defense against disease?

T cells

Imagine that the cell membrane from the previous problem becomes more permeable to Na+Na+. Predict how this will affect the RMP.

The RMP will be more positive.

What would happen to the SA node if a chemical blocker was used to reduce transport of Na+ into the pacemaker cells?

The SA node would depolarize more slowly, reducing the heart rate.

What occurs if a naïve T cell binds to an antigen without receiving a co-stimulatory signal?

The T cell enters a state of anergy.

You are going to record RMP from a cell using an electrode. You place your electrode and record a resting membrane potential every millisecond. You record an initial value of -70mV; however, over time you notice that your recordings become more and more positive until the RMP reaches 0mV. Assuming that Na+Na+ and K+K+ are the major determinants of RMP in this cell, which of the following could best explain your results?

The cell's Na+Na+-K+K+ ATPase pumps have stopped functioning.

The resting membrane potential is dependent upon two important factors: 1) differences in sodium and potassium concentrations across the membrane (electrochemical gradients) and 2) differences in sodium and potassium membrane permeability. This activity will help you to review how the resting membrane potential of cells are generated and maintained. Use the provided ions to correctly complete each sentence about the resting membrane potential. Ions may be used more than once, or not at all.

The concentration of Na+ is higher outside than inside the cell. The concentration of K+ is higher inside than outside the cell. The resting membrane potential is maintained by Na+-K+ pumps that actively transport K+ into and Na+ out of the cell. The membrane is more permeable to K+.

Many neurons have many short, branching extensions called dendrites. What is the benefit of these structures for a neuron?

The dendrites provide a large surface area for connections from other neurons.

Your clinical instructor wants a brief description of the four cardinal signs of inflammation. What would you tell him?

The heat and redness are caused by increased blood flow to the infected areas, and the pain and swelling are caused by excessive leakage of fluid from the capillaries into the infected area.

After you note a murmur in a newborn, the pediatric cardiology consultant diagnoses a patent ductus arteriosus. Why is this a cause for concern?

The higher pressure in the aorta will push extra blood through the ductus arteriosus into the child's pulmonary circulation.

Why does regeneration of the action potential occur in one direction, rather than in two directions?

The inactivation gates of voltage-gated Na+‎ channels close in the node, or segment, that has just fired an action potential. Submit

Which of the following is NOT a difference between graded potentials and action potentials?

The magnitude of action potentials decrease as the impulse travels further away from the start of the impulse while graded potentials do not decrease in magnitude.

What is the function of the myelin sheath?

The myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals.

You discover that a new chemical compound interacts with K+ voltage-dependent channels. What would be the effect on a neuron if the chemical came into contact with the axonal membrane?

The neuron would be unable to repolarize. Submit

Which description of the heart or its coverings is INCORRECT?

The parietal layer of the serous pericardium is also known as the epicardium of the heart wall. Submit

Match these prefixes and roots to their meanings.

The prefix cardi- means heart or heart action. The prefix ventriculo- means ventricle of the heart. The prefix atri- means atrium. The prefix electro- means electricity.

Which statement is correct regarding the ventricles?

The right ventricle empties into the pulmonary trunk.

Match these root words to their meanings.

The root word immuno- means immunology or physical immunity. The root word hist- means tissue. The root word phago- means eating or feeding. The root word neutr- means neutral or neutrophil. The root word -toxic means poison.

Match these vocabulary terms to their meanings.

The structure dividing the two atria of the heart is called the interatrial septum. Atrioventricular valves control blood flow into the ventricles. Tachycardia is a faster than normal heart rate. A test that records the electrical activity of the heart is a(n) electrocardiogram.

Match these prefixes, suffixes and roots to their meanings.

The word root -phag- means feeding or eating. The word root phospho- means phosphate or phosphorus. The word root angio- means blood or lymph vessels. The word root -tropic means attracted specifically to the specified organ or tissue. The word root -uria means urine.

Action potentials (nerve impulses) are changes in the membrane potential that, once started, will affect the entire excitable membrane. The first action potential is usually generated at the initial segment of the neuron's axon. This activity will test your understanding of the sequence of events that occur at the membrane of the initial segment of the axon during generation of an action potential. Place the events involved in generation of an action potential in the correct order of occurrence from left to right.

Threshold stimulusNa+ channels open Na+ influxDepolarization Na+ channels closeK+ channels open K+ effluxRepolarization HyperpolarizationK+ channels close

Name the irregular ridges of muscle lining the ventricles.

Trabeculae carneae

Identify the right atrioventricular valve.

Tricuspid valve

Blood on the right never mixes with blood on the left, once the heart is fully developed.

True

Bundles of axons in the central nervous system are called tracts.

True

If the neuron membrane becomes more permeable to Na+, Na+ will transport across the membrane, causing the cell to depolarize.

True

Opening K+ or Cl- channels in a postsynaptic membrane would produce an inhibitory postsynaptic potential (IPSP).

True

The adrenal medulla is stimulated to release catecholamines during a stress response.

True

The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human.

True

​Identify the phases of the cardiac cycle by dragging the appropriate labels to their respective targets.

Ventricular filling Isovolumetric contraction Ventricular ejection Isovolumetric relaxation

Match these vocabulary terms to their meanings.

When potassium channels have been open long enough to over-shoot resting membrane potential, hyperpolarization has occurred. Endorphins are a group of natural chemicals that reduce the perception of pain. When a neuron is stimulated and sodium channels open, the process of depolarization has begun. Supporting cells of the nervous system are collectively called neuroglia. Two consecutive neurons communicate at a synapse, where they physically come together. Structures of the nervous system surrounding, but not part of the central nervous system are part of the peripheral nervous system.

What type of event is required for an action potential to be generated?

a threshold level depolarization

What is the primary function of hormones?

act as chemical messengers that regulate the metabolic function of cells in the body Submit

Which of the following is characteristic of water-soluble hormones?

acting through second messengers at their target cells

What is the mechanism of action of lipid-soluble hormones?

activation of genes, which increases protein synthesis in the cell

After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do?

acts as a transcription factor and binds to DNA, activating a gene

Which of the following is NOT an endocrine gland?

adenoid

Secretion of __________ is increased in response to stress.

adrenocorticotropic hormone

What tropic hormone stimulates cortisol from the adrenal gland?

adrenocorticotropic hormone (ACTH)

What hormone, indicated by letter B, is released by the anterior pituitary to target the adrenal cortex when the body is under stress?

adrenocorticotropic hormone (ACTH) Submit

Which hormone is essential to our ability to maintain our fluid levels?

aldosterone

Which of the following types of cells display protein fragments produced by the cancer within them?

all nucleated cells

What is the name of the unique area (specific region) that a lymphocyte recognizes and binds to?

an antigenic determinant

Which molecules of the adaptive defense system provide humoral immunity by circulating freely in the blood and lymph, where they bind to extracellular antigens and inactivate them and mark them for destruction?

antibodies

Which of the following chemicals do NOT directly trigger inflammation?

antibodies

What hormone released into the blood by the posterior pituitary would reduce the amount of urine that is formed?

antidiuretic hormone (ADH)

Which of the following activate CD8 cells?

antigen fragments on class I MHC proteins

Class II MHC proteins are found on which of the following cell types?

antigen-presenting cells

Vaccines provide what type of immunity?

artificially acquired active

The P wave on an electrocardiogram represents __________.

atrial depolarization

What best describes afterload?

back pressure exerted by arterial blood

The amplification of the signal from a water-soluble hormone is achieved through an increase in _______.

cAMP in the cytoplasm

What hormone is released by the cells pictured in letter D?

calcitonin

If a virus attacks a cell, which type of immunity would be activated?

cell-mediated immunity (cellular immunity)

What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor?

chaperone proteins (chaperonins)

Which vessel carries blood from the anterior surface of the left ventricle to its posterior surface?

circumflex artery

Which class of MHC proteins presents exogenous antigens?

class II MHC proteins

The beginning of the QRS complex of the electrocardiogram (ECG) immediately precedes which of the following events?

closing of the atrioventricular valves

The first heart sound (the "lub" of the "lub-dup") is caused by __________.

closure of the atrioventricular valves

Which antimicrobial protein triggers inflammation?

complement

An increase in sympathetic stimulation of the heart would increase stroke volume by increasing __________.

contractility

What is the function of the ventral hypothalamic neurons?

control secretion of thyroid stimulating hormone (TSH)

Which of the following hormones has intracellular receptors?

cortisol

What type of T cell can directly attack and kill other cells, such as virus-infected cells?

cytotoxic T (TC) cells

Activated CD8 T cells become __________.

cytotoxic T cells

Which of the following cells engulf antigens by phagocytosis and present fragments of them on their own surfaces for recognition?

dendritic cells

Which of the following phases involves white blood cells leaving capillaries?

diapedesis

What does the ECG wave tracing represent?

electrical activity in the heart Submit

Which of the following would increase cardiac output?

epinephrine

Which membrane potential occurs because of the influx of Na+ through chemically gated channels in the receptive region of a neuron?

excitatory postsynaptic potential

Which of these is a condition marked by premature ventricular contraction?

extrasystole

Discharge is one of the cardinal signs of inflammation.

false

Increasing end-diastolic volume (EDV) and end-systolic volume (ESV) will increase stroke volume.

false

The right side of the heart is considered the systemic circuit pump.

false

The role of the chordae tendineae is to open the AV valves at the appropriate time.

false

Unless they are attached to protein carriers, haptens have immunogenicity but not reactivity.

false

When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane?

fast calcium

What type of cell is shown at letter C?

follicular cells

Which of the following descriptions does not describe atrioventricular (AV) valves?

formed from pocket-like cusps

Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane?

gap junctions

What causes the aortic semilunar valve to close?

greater pressure in the aorta than in the left ventricle Submit

What causes heart sounds?

heart valve closure

Which of the following are NOT appropriately matched?

helper T cells: destroy infected body cells

Which lymphocytes act as the bridge between the cellular and humoral responses?

helper t cells

What type of immunity can be transferred by bodily fluids from one person to another, thus conferring immunity to the recipient?

humoral immunity

Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized?

hypothalamus

Which of the following are NOT correctly matched?

immediate hypersensitivity: allergic contact dermatitis

Which of the following would decrease stroke volume?

increasing afterload

Tears and mucus membranes would be a part of which defense system?

innate external defenses

Phagocytotic cells such as macrophages identify a variety of enemies by recognizing markers unique to pathogens. They would be classified as which type of defense system?

innate internal defenses

What component of the reflex arc determines the response to a stimulus?

integration center

What structures connect the individual heart muscle cells?

intercalated discs

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

ion channels in the plasma membrane of the receiving neuron open.

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.

isovolumetric contraction, ventricular ejection, isovolumetric relaxation

Which heart chamber receives oxygenated blood from the lungs?

left atrium

Which cells secrete histamines that trigger inflammatory pathways?

mast cells

Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons?

microglia

Ependymal cells line many open cavities in the central nervous system (CNS). Ependymal cells have cilia on the side of the cell that face these openings. What is the most likely function of these ciliated cells?

movement and circulation of cerebrospinal fluid

Which of the following pairings does not fit?

multipolar neurons: peripheral nervous system sensory neurons

What is the most important regulatory factor controlling the circulating levels of thyroid hormone?

negative feedback

As part of a blood drive on campus for the American Red Cross, you and your friends have just donated 500 mlml of blood. You are now relaxing at the student lounge, waiting for A&P lab to begin. Unfortunately, even though you are thirsty, you haven't bothered to buy yourself a drink. Other than a little soreness of the skin and tissue around your median cubital vein, you feel fine. How has your 500 mlml decrease in blood volume most likely affected your cardiac output, heart rate, and stroke volume?

no change in cardiac output, increased heart rate, decreased stroke volume

In multiple sclerosis, the cells that are the target of an autoimmune attack are the _________.

oligodendrocytes Submit

Which of the following is an effect of complement activation?

opsonization

Let's consider a scenario in which the resting membrane potential changes from −−70 mVmV to +70 mVmV, but the concentrations of all ions in the intracellular and extracellular fluids are unchanged. Predict how this change in membrane potential affects the movement of Na+Na+. The electrical gradient for Na+Na+ would tend to move Na+Na+ __________ while the chemical gradient for Na+Na+ would tend to move Na+Na+ __________.

out; in

A resting neuron is an unstimulated neuron that is not presently generating an action potential. The resting membrane potential is the separation of the relative positive and negative charges across the membrane of a cell at rest. Drag the charges to the correct side of the membrane to represent the resting membrane potential of a typical neuron.

outside + inside -

Which of the following hormones is regulated by a neuroendocrine ("letdown") reflex?

oxytocin

In the brain, vision originates in the rods and cones in the retina. Separate regions of the brain decode basic information, like color, shapes, intensity of light, and there are other regions that decode information like position in space, and awareness of patterns. As you use your visual system, all of these regions are working simultaneously. This simultaneous awareness of all regions working at the same time is due to which processing pattern listed below?

parallel processing Submit

Which gland secretes the most important hormone controlling calcium balance in the blood?

parathyroid

Health workers working with diphtheria commonly receive a serum with antibodies against the pathogen. What type of immunity would this be?

passive, artificial immunity

Which of these mechanisms do cytotoxic T (TC) cells use to destroy a target--that is, to deliver a lethal hit?

perforation of the membrane

Cyclic AMP is degraded by __________.

phosphodiesterase

What cells make antibodies?

plasma B cells

Water-soluble hormones affect target cells by binding to __________.

plasma membrane receptors

One of the changes that occurs in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion?

potassium

You are working on a new medication to selectively kill cancer cells. You test the drug on a culture of normal neurons to check for any side effects. Despite the presence of the drug, a normal resting membrane potential of −−70 mVmV is maintained. Look at each of the figures below to analyze how the drug might be affecting the neuron. Figure A shows neuron activity under normal, or control, conditions (without the drug). Figure B shows neuron activity that has been altered due to exposure to the drug. Based on these results, the drug is most likely __________.

preventing Na+Na+-gated channels from opening

Which hormone stimulates mammary glands to produce milk in nursing mothers?

prolactin

Which of the following does NOT deliver deoxygenated blood to the heart?

pulmonary veins

Which type of chemical induces fever?

pyrogens

Which of the following terms is correctly matched to its description?

quiescent period: period of total heart relaxation

Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing?

reverberating circuit

Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing, and certain motor activities (such as arm swinging when walking)?

reverberating circuits

What types of antigen do mature T cells normally not recognize?

self-antigens

Which of the following provides a first line of defense against pathogens?

skin and mucous membranes

The anatomy of the intrinsic conduction system causes contraction of the ventricles to begin at the apex and move superiorly. Why is this important?

so blood is forced upward, toward the semilunar valves

Why are children given vaccinations?

so that they will develop antibodies against various disease-causing pathogens

Which of the following is not an antigen-presenting cells (APC)?

t cell

In order to cause cardiac muscle contraction, the contractile cells must also depolarize. What causes the depolarization of the contractile cells?

the flow of positive ions from adjacent cells

Which of the following is NOT a chemical barrier that helps prevent infections?

the pH of the blood

What determines whether a particular cell is able to respond to a hormone?

the presence of a specific hormone receptor Submit

If a signal from a sending neuron makes the receiving neuron more negative inside,

the receiving neuron is less likely to generate an action potential.

As you start working out, you notice that your heart rate and breathing rate start to increase. Which division of your nervous system is generating this response? Be as specific as possible.

the sympathetic division of the autonomic nervous system

T cells achieve self-tolerance in the __________.

thymus

Which hormone's receptor is always bound to DNA, even when the receptor is empty?

thyroid hormone

The __________ valve is located between the right atrium and the right ventricle.

tricuspid

Which valve is located between the right atrium and ventricle?

tricuspid valve

The various hormones secreted by the anterior pituitary that regulate the secretion of hormones from other endocrine organs are called __________.

tropins

What does the QRS wave of the electrocardiogram (ECG) represent?

ventricular depolarization

What does the QRS complex represent in the ECG wave tracing?

ventricular depolarization Submit

Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.

ventricular diastole

The generation of an action potential in a neuron requires the presence what type of membrane channels?

voltage-gated channels

Repolarization of an autorhythmic cell is due to the opening of which channels?

voltage-gated potassium channels

Which class of tissue graft is the LEAST likely to be accepted by a patient's body?

xenograft