Human Physiology Test 3

Surgical removal of the sinoatrial node would most likely result in A) initially, slower overall contractions but eventually, the AV node would become the new pacemaker. B) faster contractions of the atria. C) slower contractions of the atria but faster ventricular contractions. D) faster contractions of ventricles. E) slower contractions of the ventricles but faster atrial contractions.

A) initially, slower overall contractions but eventually, the AV node would become the new pacemaker.

Given the following components of the cardiac conduction cycle, which of the following best describes the movement of the stimulus that causes a heart contraction? A. atrioventricular bundle B. sinoatrial node C. atria D. atrioventricular node E. Purkinje fibers F. ventricles A) B, D, A, C, E, F B) B, C, D, A, E, F C) B, C, D, F, A, E D) A, D, E, B, C, F E) D, A, E, F, B, C

B) B, C, D, A, E, F

In the ________ circuit, blood leaving the ________ ultimately delivers oxygen and nutrients to all of the body's tissues and organs. A) Pulmonary, lung capillaries B) Systemic, left ventricle C) Systemic, vena cava D) Pulmonary, torso and lower limbs

B) Systemic, left ventricle

The advantage of having memory cells in our specific defenses is A) they prevent viruses from entering the body a second time. B) if exposed to an antigen a second time, they quickly become plasma cells. C) that they remain in an active, ready state following exposure to an antigen. D) they prevent production of other proteins so that antibodies can be produced. E) they produce antibodies and can become phagocytic.

B) if exposed to an antigen a second time, they quickly become plasma cells.

Passive immunity differs from active immunity in that passive immunity A) is not effective against a preexisting condition. B) results in the production of memory cells. C) involves the administration of preformed antibodies. D) causes long-term immunity. E) results in the production of antibodies.

C) involves the administration of preformed antibodies.

Why do some physicians advise patients with a bladder infection to drink a lot of cranberry juice? A) Cranberry juice increases the efficiency of urine production by the kidneys. B) Cranberry juice contains chemicals that kill viruses and bacteria. C) The increased volume of fluid in the bladder causes bacterial cells to burst as they absorb the excess fluid. D) Cranberry juice makes the urine more acidic, decreasing the rate at which microorganisms can grow and reproduce. E) All of the above are correct.

D) Cranberry juice makes the urine more acidic, decreasing the rate at which microorganisms can grow and reproduce.

Which of the following is correct regarding the structure of an antibody? A) An antibody is made up of two polypeptide chains linked by hydrogen bonds. B) The innermost regions of the variable regions of the polypeptides in an antibody form antigen-binding sites. C) The polypeptides making up an antibody are connected by hydroden bonds. D) Larger polypeptides making up an antibody are called heavy chains. E) Only one polypeptide in an antibody has a constant region and a variable region.

D) Larger polypeptides making up an antibody are called heavy chains.

Which of the following leukocytes kills its target cells by releasing chemicals that break down the target cell membrane? A) B lymphocytes B) basophils C) macrophages D) T lymphocytes E) natural killer cells

D) T lymphocytes

Once a prion enters a nerve cell, it essentially A) differentiates into a non-replicating virus. B) differentiates into a replicating virus. C) stops the cascade of mis-folding events associated with adjacent project. D) becomes self-propagating. E) assumes the correct folding orientation for the protein.

D) becomes self-propagating.

Fluid that "escapes" from the circulatory system due to high pressure is referred to as A) digestive fluid. B) aneurysm. C) formed elements. D) interstitial fluid. E) platelets.

D) interstitial fluid.

Which of the following body fluids does not transmit HIV from human to human? A) semen B) breast milk C) vaginal fluid D) saliva E) blood

D) saliva

Electrical impulses that stimulate contraction of heart muscles are initiated in the A) Bundle of His. B) Atrioventricular node. C) left ventricle. D) sinoatrial node. E) Purkinje fibers.

D) sinoatrial node.

The primary immune response A) produces antibodies and immunity. B) involves recognition of an antigen. C) has a lag time of approximately 20 days. D) involves the production and proliferation of T cells. E) All of the above are correct.

E) All of the above are correct.

Once a macrophage engulfs a bacterium, what is the fate of the foreign cell? A) It is released into the lymph system for removal from the body. B) Antibodies penetrate the macrophage to lyse the bacterial cell. C) The macrophage is attacked by antibodies, killing the cell and bacterium. D) It is released into the digestive tract for removal from the body. E) The bacterium is killed by digestive enzymes released from lysosomes.

E) The bacterium is killed by digestive enzymes released from lysosomes.

Which of the following antiviral drugs is used to cure HIV/AIDS? A) AZT B) ddC C) 3TC D) d4T E) There is no cure for AIDS.

E) There is no cure for AIDS.

Blood movement in veins is aided by A) pressure changes associated with breathing. B) contractions of skeletal muscles. C) one-way valves inside of veins. D) movement of limbs. E) all of the above are correct.

E) all of the above are correct.

8) The left ventricle has a more muscular wall than the other three chambers of the heart because the left ventricle A) pumps blood more rapidly than the other chambers. B) pumps blood into the atria. C) must decrease the amount of pressure on the blood so it can flow more smoothly. D) receives blood directly from major arteries. E) must generate enough blood pressure to pump blood into the aorta.

E) must generate enough blood pressure to pump blood into the aorta.

An onset of AIDS is characterized by A) T cell count of 100 per cubic millimeter of blood B) absence of HIV antibodies C) presence of an opportunistic infection D) swollen lymph nodes, chills, fever, body aches

A) T cell count of 100 per cubic millimeter of blood

Identify the diagram above. A) antibody B) antigen C) pyrogen D) interferon E) complement

A) antibody

In a weaken heart, the heart begins to pump less blood, resulting in blood backing up in the veins causing pressure in veins and capillaries to rise. This condition is called A) congestive heart failure. B) atherosclerosis. C) hypertension. D) hypotension. E) angina.

A) congestive heart failure.

Which of the following is characteristic of the parasympathetic nervous system? A) dilation of blood vessels B) increase in the rate of heart contraction C) increase in blood pressure D) secretion of the hormone epinephrine E) activation during times of stress

A) dilation of blood vessels

Lupus erythematosus is an autoimmune disorder in which the body attacks A) its own connective tissue. B) heart tissue. C) the spleen. D) its own antibodies. E) the brain.

A) its own connective tissue.

Which of the following is true regarding arterioles and arteries? A) Blood pressure is higher in arterioles than arteries. B) The wall of an arteriole has less smooth muscle than the wall of an artery. C) Arterioles and arteries transport blood from capillaries to veins. D) Small sphincters regulate the flow of blood from arteries to arterioles. E) Unlike arterioles, arteries can regulate the amount of blood that passes into capillaries.

B) The wall of an arteriole has less smooth muscle than the wall of an artery.

When comparing viruses and bacteria, which of the following is correct? A) Viruses are pathogens; bacteria are decomposers. B) Viruses and bacteria contain genetic material. C) Viruses and bacteria reproduce on their own. D) Viruses are larger than bacteria. E) Viruses have membrane-bound organelles; bacteria do not have membrane-bound organelles

B) Viruses and bacteria contain genetic material.

Which of the following best describes an angiogram? A) a sensation of pain in the chest associated with poor blood circulation to the heart B) an x-ray picture of blood vessels C) a recording of the electrical activity of the heart D) a recording of heart sounds E) use of a balloon to widen an artery

B) an x-ray picture of blood vessels

Which of the following would result in a decrease in cardiac output? A) strong emotions B) decreased stroke volume C) increased heart rate D) exercise E) activation of the sympathetic nervous system

B) decreased stroke volume

6) Fluid in the lymphatic system, as well as interstitial fluid, is A) the liquid portion of fluid escaping from the digestive system. B) derived from connective tissue. C) composed mostly of formed elements from blood. D) pumped from the left ventricle into lymphatic vessels and then back into the right atrium. E) produced by the endothelium to lubricate the interior of vascular tissue.

B) derived from connective tissue.

During cytotoxic T cell attack of a target cell, ________ is released to pierce the cell membrane of the foreign cell, which ultimately kills the target cell. A) eosinophil B) perforin C) histamine D) interferon E) All of the above are correct.

B) perforin

Which of the following conditions is typically treated by cardioversion? A) hypertension B) ventricular fibrillation C) aneurysm D) heart murmur E) stroke

B) ventricular fibrillation

The following is a list of steps involved in the process of phagocytosis. Which of the following answers puts these steps in the correct order? 1. lysosome fuses with vesicle containing a foreign cell 2. wastes from the foreign cell are removed 3. foreign cell is surrounded by the cell membrane of the phagocyte 4. lysosomal enzymes break down the foreign cell 5. foreign cell contained within a vesicle A) 5, 3, 1, 4, 2 B) 2, 4, 1, 5, 3 C) 3, 5, 1, 4, 2 D) 3, 1, 5, 4, 2 E) 3, 5, 2, 1, 4

C) 3, 5, 1, 4, 2

Which of the following is true regarding lymph nodes?A) Lymph flows from the lymph vessels to the urinary system. B) Macrophages but not lymphocytes can be found within lymph nodes. C) They filter lymph fluid. D) They remove microorganisms and abnormal cells from lymph and return them to blood circulation. E) They are located only in the digestive tract and neck.

C) They filter lymph fluid.

Skin is able to prevent most microorganisms from entering the body by A) production of antibodies. B) releasing macrophages on the skin surface. C) having keratin in the uppermost layer. D) producing alkaline secretions. E) the adhesion junction in the skin preventing bacteria from entering.

C) having keratin in the uppermost layer.

An electrocardiogram is used to A) correct a heart murmur. B) listen to heart sounds. C) measure the electrical activity of the heart. D) measure the amount of blood leaving the heart with each contraction. E) initiate angina pectoris.

C) measure the electrical activity of the heart.

Cardiac output can be calculated by A) monitoring changes in blood pressure for a specific period of time, but for at least 15 minutes. B) summing heart rate, stroke volume and blood pressure. C) multiplying heart rate by stroke volume. D) dividing stroke volume by arterial blood pressure. E) measuring the number of heartbeats in one hour.

C) multiplying heart rate by stroke volume.

Which of the following parts of the brain regulates heart activity? A) cerebellum B) midbrain C) cerebrum D) medulla oblongata E) thalamus

D) medulla oblongata

A mild fever is part of the body's second line of defense and aids the body by A) increasing the rate of tissue repair. B) creating an inhospitable internal environment for pathogenic bacteria. C) speeding up defense reactions. D) increasing the metabolic rate of body cells. E) All of the above are correct.

E) All of the above are correct.

Bacteria are helpful to humans in many ways, including A) breakdown of raw sewage. B) production of soy sauce. C) production of antibiotics. D) production of vitamins for the human body. E) All of the above are correct.

E) All of the above are correct.

The structure of medium and large-sized arteries is ideally suited to meet the function of these blood vessels as evidenced by...? A) the presence of an endothelial lining that creates a slick surface. B) elastin fibers that allow stretching of the arteries. C) a tough supportive layer of connective tissue containing collagen. D) a smooth muscle layer on the outside, which stiffens arteries. E) all of the above

E) all of the above

Which structural feature of capillaries promotes exchange between blood and interstitial fluid? A) a flat and thin endothelium B) an endothelium that leaks because of pores C) lack of connective tissue D) lack of smooth muscle E) all of the above are correct.

E) all of the above are correct.

The atrioventricular valves are closed when A) the heart is completely relaxed. B) the right atrium is contracting. C) the ventricles are relaxed. D) the P wave of an electrocardiogram appears. E) the ventricles contract.

E) the ventricles contract.