Mastering A&P 2

Which of the following is NOT a benefit of breathing through the nose? -filtration of the air entering the nasal cavity -recovering heat and moisture from the air leaving the nasal cavity -the production of smooth, laminar airflow as air passes by the nasal conchae -heating and moistening the air entering the nasal cavity

-the production of smooth, laminar airflow as air passes by the nasal conchae Correct In fact, airflow becomes turbulent (not smooth or laminar) as the gases of inhaled air swirl through the twists and turns created by the curved nasal conchae protruding medially from each lateral wall of the nasal cavity. Heavier, nongaseous particles deflect onto the mucus-coated surfaces, where they become trapped. As a result, few particles larger than 6 μm make it past the nasal cavity.

Growth factor hormones, such as insulin, bind to which type of receptor? -tyrosine kinase receptors -intracellular receptors -G proteins

-tyrosine kinase receptors Correct Yes, insulin binds to tyrosine kinase receptors and works without a second messenger.

During pleurisy, the inflamed parietal pleura of one lung rubs against the inflamed ______. thoracic wall parietal pleura of the other lung visceral pleura of the same lung -visceral pleura of the other lung

-visceral pleura of the same lung Correct Normally the visceral and parietal pleura of one lung glide easily over one another during breathing because they are smooth and lubricated by pleural fluid. During pleurisy, they become rough and friction develops between the two layers..

What type of hormones bind to receptors located on the cell membrane? -lipid-soluble hormones, such as thyroid hormones and cortisol -water-soluble hormones, such as insulin and epinephrine

-water-soluble hormones, such as insulin and epinephrine Correct Yes, peptides and catecholamines are water-soluble hormones that cannot diffuse through the plasma membrane.

Focus your attention on the section called Net filtration pressure occurs at the arteriolar end of a capillary on page 2 of Focus Figure 19.1. Note that for an NFP at any point there are four pressures to be considered. Pay attention to which forces are larger and which are smaller. Note that the white arrow represents the net filtration pressure, the result of four different forces.Drag and drop the terms to the two appropriate blanks describing pressures for each sentence.

.1 The "pushing" pressure of this fluid is usually very weak: HPif ; 0 mm 2. The "pulling" pressure of this fluid is usually due to large albumens and globulins: OPc ; ~26 mm 3. The "pulling" pressure of this fluid resulting from nondiffusible solutes is very low: OPif; ~1 mm 4. The "pushing" pressure of this fluid is high and results from blood pressure: BPc ; ~35 mm

How do endocrine hormones reach their target cells? -Hormones are released at synapses adjacent to target cells. -Hormones are transported through the bloodstream to target cells. -Ducts transport hormones directly to target cells. -Hormones travel through the lymphatic system to target cells. -Hormones are produced by endocrine cells that are adjacent to target cells.

-Hormones are transported through the bloodstream to target cells Correct The bloodstream allows hormones to be distributed throughout the body.

Why does this patient have signs and symptoms so different from Mr.G's?

1. Mr. V's partly blocked tricuspid valve restricts blood flow from the RIGHT ATRIUM to the RIGHT VENTRICLE, turbulent blood flow is heard during DIASTOLE as blood is forced through the narrow opening. 2. The RIGHT ATRIUM does not empty normally, so it cannot accept a normal amount of blood from the BODY; blood accumulates in the veins and tissues, causing distended JUGULARS and SWOLLEN tissues. The excess fluid in tissues leads to weight GAIN and a HEAVY feeling in Mr. V's legs.

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

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

Why was Mr. Watkins given PRBCs in addition to normal saline solution? What problem does the infusion of PRBCs address that the saline solution could not? -PRBCs contain hemoglobin, so they are able to carry oxygen to the tissues. -PRBCs enhance clotting, sealing off the injured vessels. -PRBCs increase blood osmotic pressure, making the infused fluid stay in the vessels rather than move into the cells. -PRBCs help restore blood ion composition to normal.

-PRBCs contain hemoglobin, so they are able to carry oxygen to the tissues. Correct The PRBCs contain oxygen-carrying hemoglobin. While the saline replaces lost blood volume, it cannot replace the hemoglobin in the lost RBCs.

Which of the following enzymes are important in the deactivation of cAMP and termination of signaling? -G Protein -Protein Kinase -Adenylate Cyclase -Phosphodiesterase

-Phosphodiesterase Correct The increase in cAMP levels is usually short-lived because the enzyme phosphodiesterase is constantly present in the cytoplasm of the target cells.

Which of these vessels returns blood to the left atrium of the heart? -Pulmonary Veins -Superior Vena Cava -Pulmonary Trunk -Coronary Sinus

-Pulmonary Veins The pulmonary veins transport oxygen-enriched blood from the lungs to the left atrium

What is the target of thyroid hormones? -hypothalamus -anterior pituitary -thyroid -cells of the body

-cells of the body Correct Thyroid hormones secreted by the thyroid gland target cells of the body to modulate metabolism.

What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor? -Receptors can't enter the nucleus until the hormone is bound to it. -transcription factors -chaperone proteins (chaperonins)

-chaperone proteins (chaperonins) Correct Yes, each receptor has two binding sites. The chaperone protein blocks the DNA binding site until a hormone binds at the hormone binding site.

What is the function of the ventral hypothalamic neurons? -control secretion of oxytocin -control secretion of thyroid hormones -control secretion of thyroid stimulating hormone (TSH) -control secretion of antidiuretic hormone (ADH)

-control secretion of thyroid stimulating hormone (TSH) Correct Yes, neurohormones from the ventral hypothalamic neurons, known as releasing (RH) and inhibiting (IH) hormones, control the release of anterior pituitary hormones such as adrenocorticotropic hormone (ACTH) and TSH.

Which type of leukocyte provides protection against parasitic worms? -neutrophil -basophil -eosinophil -lymphocyte

-eosinophil Correct The most important role of eosinophils is to lead the counterattack against parasitic worms, such as flatworms and roundworms that are too large to be phagocytized.

Which of the following would NOT lead to a bleeding disorder? -vitamin K deficiency -thrombocytopenia -excess calcium in the diet -impaired liver function

-excess calcium in the diet Correct Calcium is essential for clotting pathways; a deficiency (not an excess) of calcium could lead to a bleeding disorder.

Which plasma constituent is the main contributor to clotting? -albumin -alpha globulins -beta globulins -fibrinogen

-fibrinogen Correct Fibrinogen comprises 4% of plasma and is an important component in the process of blood clotting.

How many oxygen molecules can be transported by one hemoglobin molecule? -two -four -eight

-four Correct Each iron atom on a heme group can bind reversibly with one oxygen molecule.

Which of the following plasma proteins is improperly matched with its function? -fibrinogen: clotting -alpha globulin: transport of metal ions and fat-soluble vitamins -gamma globulins: lipid transport -albumin: osmotic pressure

-gamma globulins: lipid transport Correct Gamma globulins are also called immunoglobulins (or antibodies) and are part of the immune response.

Suppose Krista's hyperthyroidism was a result of a tumor that causes the anterior pituitary gland to become overactive. Which of the following would Krista's lab reports likely show? -low thyroid hormone, high TSH -high thyroid hormone, low TSH -high thyroid hormone, high TSH -low thyroid hormone, low TSH

-high thyroid hormone, high TSH Correct An increase in TSH from the anterior pituitary will increase levels of thyroid hormone. The high levels of thyroid hormone will not be able to inhibit the anterior pituitary by negative feedback due to the presence of the tumor.

The body's tendency to maintain relatively constant internal conditions is called -homeostasis -positive feedback -diabetes -negative feedback -none of the above

-homeostasis

Which of the following is not a function of blood? -protection from infection -transport of metabolic wastes -hormone production -homeostatic regulation

-hormone production Correct The blood does not produce hormones but does provide for their transport throughout the body.

What type of stimulation controls parathyroid release? -paracrine -hormonal -neural -humoral

-humoral Correct The parathyroid is stimulated by the actual level of calcium in the blood rather than by neural or hormonal stimulus.

Which of the following does NOT stimulate erythrocyte production? -hyperventilating -a drop in blood oxygen levels -erythroprotein -testosterone

-hyperventilating Correct Hyperventilating leads to an above-normal level of oxygen in the blood, which would not stimulate RBC production.

Most water-soluble hormones exert their effects through the second messenger cyclic AMP (cAMP). This activity will test your understanding of the events that occur during cAMP signaling. Drag the events of cAMP signaling in the correct sequence from left to right.

1. Water-soluble hormone binds receptors 2. Receptor activates G protein 3. G protein activates adenylate cyclase 4. Adenylate cyclase generates cAMP 5. cAMP activates protein kinases Correct Activated protein kinases can then phosphorylate a variety of intracellular proteins to elicit the cell's response to the hormone.

Using the spirographic data shown, what is the minute ventilation of an average adult male at rest breathing at a rate of 10 breaths per minute? 5000 milliliters per minute 36000 milliliters per minute 48000 milliliters per minute 60000 milliliters per minute

5000 milliliters per minute Correct The minute ventilation is calculated by multiplying the breaths per minute by the tidal volume, so in this case, 10 breaths/minute × 500 ml/breath = 5000 ml/minute.

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 Correct The SV is calculated by subtracting the ESV from the EDV. You are comparing the volume of the ventricle at its fullest to its emptiest.

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 Correct Cardiac output is the product of heart rate times stroke volume. Cardiac output increases to meet increased metabolic demand, often by increasing both heart rate and stroke volume at the same time. This occurs, for example, during maximal exercise, when cardiac output may increase to four or five times the resting level.

Refer again to the entire focus figure. Using the same client, Mr. Orange, with the same pressures, what is the client's NFP at the venous end, NFPv?

= (22 + 1) - (26 + 0) = -3 mm Correct Blood pressure, HPc, decreases by about 50% from arteriolar to venous end of the capillary bed.

Acromegaly may be caused by all EXCEPT which of the following? -hypersecretion of GHRH (growth hormone-releasing hormone_ -pancreatic tumor -lack of negative feedback by insulin-like growth factors -hyposecretion of GH in adulthood

-hyposecretion of GH in adulthood Correct Acromegaly is a disorder resulting from excessive GH secretion after epiphyseal plates have closed. There are usually no adverse effects of GH hyposecretion in adults. However, GH hyposecretion in children slows the growth of long bones and, unless treated, results in pituitary dwarfism. Growth hormone secretion is stimulated by GHRH (growth hormone-releasing hormone).

Where is thyrotropin-releasing (TRH) made? -follicular cells of the thyroid gland -posterior pituitary -hypothalamus -anterior pituitary

-hypothalamus Correct The hypothalamus regulates the release of several hormones by producing releasing and inhibitory hormones, including thyrotropin-releasing hormone (TRH).

Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized? -kidney -hypothalamus -posterior pituitary -anterior pituitary

-hypothalamus Correct Yes, ADH is synthesized mainly in the supraoptic nucleus of the hypothalamus. It is stored in the posterior pituitary in axon terminals.

As the adrenal gland releases glucocorticoids, which of the following effects may be observed? Select all the answers that apply.

-increased blood glucose levels -increased blood levels of amino acids -decrease in immune system function -lipid breakdown in the liver will increase Correct With long-term stress, the glucocorticoid hormones, chiefly cortisol, are instrumental in the body. The primary targets include the liver, resulting in increased gluconeogenesis and increased catabolism of lipids and proteins. In larger amounts, the depression of the immune system can result.

Adrenocortical androgens are normally converted in females into estrogens. However, in adrenogenital syndrome, females develop a beard and a masculine pattern of body hair distribution; this occurs due to ______. -negative feedback that inhibits estrogen production -conversion of estrogens into testosterone -insufficient level of enzymes that convert androgens into estrogens -increased testosterone secretion

-insufficient level of enzymes that convert androgens into estrogens Correct During the end steps of sex hormone, synthesis androstendione is converted into either testosterone or estrogen. If the body lacks the enzyme to convert androstendione to estrogen, the remaining pathway to testosterone will predominate.

Which of the following triggers the release of glucagon? -releases of somatostatin -hyperglycemia -release of insulin -prolonged fasting

-prolonged fasting Correct Glucagon acts to stimulate release of glucose into the blood to counteract falling levels.

What triggers erythropoietin (EPO) production to make new red blood cells? -a high hematocrit -reduced availability -excess oxygen in the bloodstream -too many platelets

-reduced availability of oxygen Correct Reduced oxygen delivery to the kidneys will result in the release of erythropoietin (EPO), which in turn promotes the release of more erythrocytes from the bone marrow.

Which chamber receives blood from the superior and inferior vena cavae? -left atrium -right ventricle -right atrium -left ventricle

-right atrium Correct Yes, the right atrium receives unoxygenated blood from the systemic circuit.

Which heart chamber pumps unoxygenated blood out the pulmonary trunk? -left ventricle -left atrium -right ventricle -right atrium

-right ventricle Correct Yes, the right ventricle pumps unoxygenated blood out the pulmonary trunk to the lungs.

Pheochromocytoma produces symptoms of uncontrolled sympathetic nervous system activity. Which of the following is common to both adrenal chromaffin cells and adrenergic fibers of the sympathetic nervous system? ' -the presence of axons capable of secreting substances that are capable of increasing heart rate -secretion of epinephrine -secretion of norepinephrine -All of the listed responses are correct

-secretion of norepinephrine Correct Adrenal chromaffin cells are capable of releasing the hormones epinephrine and norepinephrine into the systemic circulation. Post-ganglionic neurons of the symphathetic nervous system also release norepinephrine.

All of the following conditions would stimulate the pancreas to release insulin EXCEPT one. Which one? -a rise in blood glucose levels -a rise in blood amino acid levels -acetylcholine release on the pancreatic cells -sympathetic activation

-sympathetic activation Correct Sympathetic activation is designed to increase blood glucose levels, so it inhibits the release of insulin.

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. Correct This answer is correct. The activated B cell divides until there are many clones. Some differentiate into memory cells, other become plasma cells that produce and secrete antibodies.

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? -parathyroid hormone (PTH) -syndrome of inappropriate antidiuretic hormone (SIADH) -thyroid-stimulating hormone (TSH) -prolactin

-syndrome of inappropriate antidiuretic hormone (SIADH) Correct Antidiuretic hormone (ADH) is released from the posterior pituitary in response to rising serum osmolality. This causes the kidneys to preserve water, helping to restore normal solute/water balance. Your patient is retaining water despite a dilute plasma, suggesting that he is making "inappropriate" ADH. This problem may occur after head trauma or in some cancers.

When blood glucose levels are high -the pancreas releases insulin -the pancreas releases glucagon -the pancreas releases glucose -the liver releases insulin -the liver releases glucagon

-the pancreas releases insulin Correct The pancreas responds to high blood glucose levels by releasing insulin.

Despite the fact that the partial pressure difference is so much smaller for CO2, why is there as much CO2 exchanged between the alveoli and blood as there is O2, ? -The capillary walls are more permeable to CO2 than O2. -CO2 is much more soluble in blood than O2. -CO2 is a smaller molecule and diffuses faster than O2O2.

CO2 is much more soluble in blood than O2 Correct Yes, because CO2CO2 is very soluble in blood, it does not require as large a pressure gradient as O2O2.

_______ has a greater partial pressure in the pulmonary capillaries than in the alveoli, so it diffuses into the -O2; pulmonary cavities -CO2; pulmonary capillaries -CO2; alceoli -O2; alveoli

CO2; alveoli Correct Yes, CO2 diffuses along its partial pressure gradient from the pulmonary capillaries into the alveoli until equilibrium is reached.

In contrast to a skeletal muscle cell action potential, why does the action potential for a cardiac muscle cell contain a "plateau" phase?

Cardiac muscle cells contain slow Ca2+Ca2+ channels in their sarcolemma that continue to allow influx of Ca2+Ca2+ ions after Na+Na+ channels are inactivated. Correct Fast voltage-gated Na+Na+ channels are open only for a very brief time before they are inactivated, but the resulting depolarization opens slow Ca2+Ca2+ channels that start a positive feedback cycle that temporarily keeps the membrane potential high.

Which of the following best describes the chloride shift as seen in the figure? -Chloride is taken out of the blood to counterbalance the inflow of carbon dioxide. -Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. -Chloride binds to bicarbonate, which allows more of it to be carried in the bloodstream. -Chloride is removed from hemoglobin when carbon dioxide binds to it.

Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. Correct The outflow of negative bicarbonate ions from RBCs is balanced by the inflow of chloride ions.

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 Correct B cells can still bind to antigen, which is the process of clonal selection. However, without a helper T cell, clonal expansion and antibody production will not occur.

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

Closing of atrioventricular valves Correct Heart sounds are an extremely helpful diagnostic tool that is not invasive. The first heart sound, often described as a lubb, corresponds to the closing of the atrioventricular valves. The second heart sound is a sharper and crisper dupp that corresponds to the closing of the semilunar valves. Consequently, the two heart sounds mark the beginning and the end of ventricular systole.

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

Contractility Correct Increased sympathetic activity increases heart contractility. This causes cardiac fibers to contract more forcefully at all levels of preload. Regardless of end diastolic volume, this mechanism increases stroke volume by reducing end systolic volume.

Focus your attention on the section of the capillary bed in the area called The big picture in Focus Figure 19.1. Drag and drop the correct identification label to the figure with a leader line.

Correct Recall that blood flows from a larger diameter artery forward to a microscopic arteriole that can carry blood into a capillary bed. The vessel exiting the capillary bed, the microscopic venule, carries blood to a vein for its journey back to the heart. Along this pathway, the blood hydrostatic pressure changes. There is a significant drop in blood pressure, ~50%, between the arteriolar end of the capillary bed and the venule end.

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.

Correct The balance between parasympathetic and sympathetic stimulation to the heart controls heart rate. Increased parasympathetic activity decreases heart rate, and sympathetic activity increases heart rate.

Drag and drop the labels onto the figure to identify the events associated with the cardiac cycle. Use each label once.

Correct The cardiac cycle reflects pressure changes in several key structures of the heart; the volume changes as blood moves through the heart and, finally, the electrical events associated with heart contraction. Review Focus Figure 18.2 for each of the line graphs and their relation to the cardiac cycle.

Which statement is correct? -The greater the available surface area the lower the amount of gas exchange during internal respiration. -During internal respiration, carbon dioxide is unloaded from the blood. -During external respiration, oxygen is unloaded from the blood. -During external respiration, equilibrium is reached for O2O2 when the partial pressure for O2O2 in the pulmonary capillaries and the alveoli are the same.

During external respiration, equilibrium is reached for O2O2 when the partial pressure for O2O2 in the pulmonary capillaries and the alveoli are the same. Correct Yes, equilibrium is reached for O2O2 when the partial pressure of O2O2 in the pulmonary capillaries and the tissue cells are the same.

Hypoalbuminemia is a medical condition in which blood plasma levels of albumin are abnormally low. One cause of this disorder is the increased movement of plasma albumin into the interstitial space through leaky blood capillaries. How would this condition affect the volume of lymph that is produced?

It would increase lymph volume.

The greater the mass of tissue in an organ, the greater its need for an adequate blood supply. Which chamber of the heart has the highest probability of being the site of a myocardial infarction? -right atrium -left atrium -left ventricle -right ventricle

Left Ventricle Correct The left ventricle actively pumps blood to almost all of the body's tissues via the aorta. It has to generate much greater force during contraction than any other heart chamber.

Which statement correctly describes the origin of lymph fluid?

Lymph is excess tissue fluid formed from plasma that has leaked from capillaries Correct As blood circulates through the body, nutrients, wastes, and gases are exchanged between the blood and the interstitial fluid. The hydrostatic and colloid osmotic pressures operating at capillary beds force fluid (plasma) out of the blood at the arterial ends of the beds and cause most of it to be reabsorbed at the venous ends. The fluid that remains behind in the tissue spaces, as much as 3 L daily, becomes part of the interstitial fluid. The lymphatic vessels collect this excess interstitial fluid (now called lymph) and return it to the bloodstream.

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 Correct Memory cells to that specific virus are stored in the lymph nodes for many years. When the student comes into contact with this specific Rhinovirus, these memory cells quickly divide and differentiate into antibody-producing plasma cells. The antibodies will prevent the virus from reaching an infectious titer (number that causes infection).

What roles do memory B cells play when a patient is re-exposed to an antigen?

Memory B cells trigger a secondary immune response, which is faster, more prolonged, and more effective than the first immune response. Correct Memory B cells that have already been activated by an antigen are primed and ready for action. They can respond very quickly to that antigen if it is encountered again, and the secondary response is faster and more effective.

Review the entire Focus Figure 19.1 again. During your review, consider what would happen if one pressure were atypical. Read through Focus Figure 19.1. Mr. Orange has hypertension (HTN) and other vessel disorders, and his brachial blood pressure is ~160/100. Assume his HPc is ~44 mm and other pressures are unaffected. What is his NFPa?

NFPa = (44 + 1) - (0 + 26) = +19 mm Correct Increase in blood pressure will typically increase the net filtration pressure at the capillary bed.

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 - Correct If your patient is experiencing an initial infection with measles, he or she should have only IgM this early in the course of this illness. This result would not be expected.

Refer to Focus Figure 18.2, specifically the graph reflecting pressure changes in the cardiac cycle. Why is the dicrotic notch important?

Reflects an increase in aortic pressure as blood rebounds against the closed aortic semilunar valve Correct Review each of the pressure line graphs in Focus Figure 18.2. As ventricular pressure decreases below aortic pressure, the aortic semilunar valve closes. In response, blood rebounds against this closed valve, producing a slight increase in the aortic pressure. This is shown on the line graph as the dicrotic notch.

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

SA node Correct Like the rest of the intrinsic conduction system, the SA node contains pacemaker cells that spontaneously depolarize. The cells within the SA node, however, depolarize faster than the other cells within the system. This causes action potentials to initiate in the SA node rather than in any of the other structures.

Examine the left side of page 1 of Focus Figure 19.1. Assume you have a U-tube with a semipermeable membrane (boundary) separating the solutions on either side. Predict what will occur to the water level if large, non-diffusible solutes are added only to the left arm of the tube.

The water level on the left side of the U-tube will rise. Correct Remember that only nondiffusible solutes will affect the water level, because the solute concentration will increase on the left side, creating osmotic pull. In the blood, nondiffusible solutes are large plasma proteins pulling or drawing fluid into the blood.

Quiet inspiration is __________, and quiet expiration is __________. -an active process; a passive process -an active process; also an active process -a passive process; also a passive process -a passive process; an active process

an active process; a passive process Correct During quiet breathing, inspiration requires muscular contractions of the diaphragm and external intercostals, while expiration occurs passively due to the elastic recoil of the lungs and the collapsing force of alveolar fluid surface tension.

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

an antigenic determinant Correct Yes, also called an epitope, the antigenic determinant is the specific part of an antigen that the antibody or lymphocyte antigenic determinant receptor binds to.

A decrease in blood pressure at the arterial baroreceptors would result in which of the following?

an increase in heart contractility Correct Yes, sympathetic nervous system activity would be increased because of the low blood pressure. Sympathetic fibers go to the ventricles of the heart and increase their contractility. An increase in contractility would increase stroke volume which would lead to an increase in cardiac output and blood pressure.

Stimulation of the adrenal medulla would result in which of the following?

an increase in heart rate and contractility Correct Yes, epinephrine and norepinephrine are released from the adrenal medulla and act as part of the sympathetic nervous system, increasing heart rate and contractility. Epinephrine and norepinephrine have other effects that would also increase blood pressure.

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 Correct Humoral immunity, also called antibody-mediated immunity, is provided by antibodies present in the body's "humors," or fluids (blood, lymph, etc.). Though they are produced by lymphocytes, antibodies circulate freely in the blood and lymph, where they bind primarily to extracellular targets—bacteria, bacterial toxins, and free viruses—inactivating them temporarily and marking them for destruction by phagocytes or complement.

Vaccines provide what type of immunity?

artificially acquired active Correct When your B cells encounter antigens and produce antibodies against them, you are exhibiting active humoral immunity. Active immunity is acquired "artificially" when you receive a vaccine. Most vaccines contain pathogens that are dead or attenuated (living, but extremely weakened), or their components. Vaccines spare us most of the symptoms and discomfort of the disease that would otherwise occur during the primary response.

What is the most common method of carbon dioxide transport? -as bicarbonate ions in the plasma -chemically bound to hemoglobin as oxyhemoglobin -dissolvfed in the plasma -chemically bound to hemoglobin as carbaminohemoglobin

as bicarbonate ions in the plasma Correct Carbon dioxide reacts with water inside RBCs to form carbonic acid, which dissociates into bicarbonate and hydrogen ions. About 70% of carbon dioxide travels in the plasma as bicarbonate.

What best describes afterload?

back pressure exerted by arterial blood Correct Afterload refers to the back pressure exerted by arterial blood, or the pressure that must be overcome for the ventricles to eject blood.

Lymphedema may be treated by all EXCEPT which of the following?

bed rest to allow enhanced blood flow and therefore healing of the affected area Correct Lymphedema is swelling that occurs when normal lymphatic drainage is blocked. If a person remains stationary, it decreases skeletal muscle contraction, which facilitates lymph drainage.

Varicose veins seen in the superficial veins of the legs are unsightly and are often treated by surgical removal. However, even without these veins being present, the return of all blood toward the heart from the legs is not diminished. This is primarily because ______.

blood can still return via the deep veins Correct The leg has a complex and highly branched venous system. The superficial and deep veins anastamose with each other at many points along their length.

In the capillaries, hydrostatic pressure (HP) is exerted by __________.

blood pressure Correct Yes, blood pressure is the driving force for filtration

A patient with a restrictive lung disease such as tuberculosis is likely to see an increase in his or her __________. -vital capacity -functional residual capacity -breathing rate -residual volume

breathing rate Correct Restrictive lung diseases decrease vital capacity, total lung capacity, functional residual capacity, and residual volume. To provide adequate ventilation, the alveolar ventilation rate must increase.

What vessels sustain a drop in pressure from approximately 35 mm Hg to around 17 mm Hg?

capillaries Correct 35 mm Hg and 17 mm Hg are typical entering and exiting pressures for a capillary bed. These pressures strongly affect the exchange of fluids across the capillary wall.

The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________.

capillary; interstitial fluid Correct Yes, the capillary hydrostatic pressure (HPC; caused by blood pressure) is much higher than the interstitial hydrostatic pressure (HPI). The interstitial fluid is forced out of the capillaries.

Where are the sensors for the arterial baroreceptor reflex located?

carotid sinus and aortic arch Correct Yes, the sensors are the arterial baroreceptors themselves, located at the carotid sinus and aortic arch. They detect changes in blood pressure by the degree of stretch on the blood vessel.

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

cell-mediated immunity (cellular immunity) Correct Yes, cell-mediated immunity involves an intracellular pathogen such as a virus.

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

closing of the atrioventricular valves Correct The QRS complex is a recording of ventricular depolarization. This depolarization begins just prior to the ventricular contraction it initiates. As the ventricles contract, the increase in ventricular pressure closes the atrioventricular valves, beginning isovolumetric contraction. As ventricular pressure increases above the corresponding blood vessel, only then do the semilunar valves open, initiating ventricular ejection.

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

closure of the atrioventricular valves Correct The first heart sound (the "lub" of the "lub-dup") is generated by the closure of the atrioventricular valves.

Which mechanism(s) of antibody action result(s) in cell lysis?

complement activation Correct Complement has the potential to bind antigen by itself (alternative pathway), but it may require an antibody to bind to the antigen first (classical pathway).

Which of the following structures would be the LEAST vulnerable to damage caused by oxygen toxicity? brain spleen muscles costal cartilages

costal cartilages Cartilage is normally avascular and receives oxygen by diffusion from surrounding capillaries

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

cytotoxic T (TC) cells Correct Cytotoxic T (TC) cells can distinguish between self cells and foreign cells. If a cytotoxic T cell recognizes its own antigen on a virus-infected cell, the T cell will destroy it.

As a result of hyperventilation, what will happen to the partial pressures of CO2 (pCO2) and pH? -decreased pCO2 and decreased pH -increased pCO2 and decreased pH -increased pCO2 and increased pH -decreased pCO2 and increased pH

decrease pCO2 and increased pH Correct Yes, pCO2 would decrease and pH would increase. As CO2 is blown off, H+ would decrease, thus increasing pH.

Which of the following would cause vasodilation of arterioles?

decreased activity of the sympathetic nervous system Correct Yes, a decrease in the activity of the sympathetic nervous system would result in decreased activity of vasomotor fibers, resulting in vasodilation.

Which of the following would decrease total peripheral resistance to blood flow?

decreasing the hematocrit Correct Decreasing the hematocrit (fraction of whole blood consisting of blood cells) would lead to decreased blood viscosity, and thus would decrease resistance.

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

dendritic cells Correct Dendritic cells are antigen-presenting cells that engulf antigens and then present fragments of them to their own surfaces, where T cells can recognize them.

Which muscles, when contracted, would increase the volume of air in the thoracic cavity? -internal intercostals and external oblique -diaphragm and internal intercostals -diaphragm and external intercostals

diaphragm and external intercostals Correct Yes, contraction of both the diaphragm (the diaphragm flattens) and the external intercostals (pulls the ribs up and out) will increase the volume of the thoracic cavity. This will cause air to move into the lungs (inspiration).

Mr. V has also had a recent echocardiogram and blood work. With tricuspid stenosis, what changes do you expect to see in the echocardiogram report? -dilated right atrium because blood is not flowing down into the right ventricle fast enough -enlarged left ventricle because blood is not flowing out into the body fast enough -decreased ejection fraction because blood cannot flow out into the aorta fast enough -dilated left atrium because blood is not flowing down into the left ventricle fast enough

dilated right atrium because blood is not flowing down into the right ventricle fast enough Correct Sure enough, when you check Mr. V's echocardiogram, you see a dilated right atrium and a slightly dilated superior vena cava. Does this help you to explain Mr. V's other signs and symptoms?

What structure prevents food and liquids from entering the trachea? -glottis -epiglottis -laryngeal prominence -vestibular folds

epiglottis Correct During swallowing, the larynx is pulled superiorly and the epiglottis tips to cover the laryngeal inlet. Because this action keeps food out of the lower respiratory passages, the epiglottis has been called the guardian of the airways.

During an allergic reaction, which of the following would aid respiration? -acetylcholine (ACh) -an increase in the parasympathetic nervous system -epinephrine -histamine

epinephrine Correct Yes, during an allergic reaction, there is increased resistance in the bronchioles and epinephrine dilates the bronchioles, thus making it easier to breathe. Epinephrine is released from the adrenal gland during stressful situations. People with severe allergies carry an EpiPen in case the allergic reaction produces anaphylaxis

Which of the following processes is NOT properly matched with its description? -external respiration: CO2 diffuses into the blood stream -internal respiration: O2 diffuses out of the blood -pulmonary ventilation: movement of gases into and out of the lungs -transport of respiratory gases: O2 is bound to hemoglobin

external respiration: CO2 diffuses into the blood stream Correct CO2 diffuses into the blood as it passes through the systemic capillaries of the tissues; this is internal respiration.

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

fast calcium Correct Yes, unlike nerve cells or cardiac muscle cells, fast calcium channels are responsible for the depolarization phase of the autorhythmic cell action potential. When the fast calcium channels open, calcium rushes into the cell making it less negative (or more positive).

As the kidneys filter blood, it is necessary for both fluid and dissolved chemicals in the plasma to be rapidly removed without the removal of larger proteins or cells. Which capillary would be best suited for the filtration?

fenestrated capillaries Correct Fenestrated capillaries are found wherever active filtrate formation occurs. Fenestrations are Swiss cheese-like holes that tunnel through endothelial cells that allow for the selective passage of smaller solute molecules.

In Baby A, the atrial septal defect did not close at birth. Blood is flowing through her defect in what direction? -from the right atrium into the left atrium -There will be no net flow across the defect. -from the left atrium into the right atrium -from the left atrium into the right ventricle

from the left atrium into the right across Correct Good. Baby A's atrial septal defect did not close properly on her first breath, so now blood is flowing from her left atrium into her right atrium. But that is not what brought her in to the doctor, is it? She is here because of respiratory infections and trouble breathing.

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

gap junctions Correct Yes, action potentials generated by the autorhythmic cells spread waves of depolarization to contractile cells through gap junctions. If the depolarization causes the contractile cells to reach threshold, they will in turn generate an action potential.

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

helper T cells Correct Helper T cells are lymphocytes that organize the cellular and humoral immune response branches of the immune system.

Which of the following are NOT appropriately matched?

helper T cells: destroy infected body cells Correct Helper T cells are lymphocytes that manage or orchestrate an immune response, but they do not directly kill cells.

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

humoral immunity Correct Yes, humoral immunity involves antibodies that can be transferred from one person to another.

If blood pressure is increased at the arterial baroreceptors, what would happen with the activity level of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS)?

increased PNS activity and decreased SNS activity Correct Yes, the PNS activity would increase and the SNS activity would decrease in an attempt to lower blood pressure.

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

innate external defenses Correct Yes, innate external defenses (surface barriers) are the first line of defense and include tears, mucus membranes, and the skin.

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 Correct Yes, the macrophage recognizes many molecules found on pathogens that are not present on normal body cells.

What protein can be released by infected cells to help protect cells that have not yet been infected?

interferon Correct Interferon is a small protein that can stimulate nearby healthy cells to defend themselves against viral infection.

Which pressure is the result of the natural tendency of the lungs to decrease their size (because of elasticity) and the opposing tendency of the thoracic wall to pull outward and enlarge the lungs? -intrapulmonary pressure -atmospheric pressure -intrapleural pressure

intrapleural pressure Correct Yes, the lungs tend to decrease their size while the chest wall tends to pull the thorax outward. This makes the intrapleural pressure more negative than the other two pressures (described as subatmospheric), thus keeping the lungs inflated.

In pneumothorax, the lung collapses because ______. -intrapleural pressure is lower than trans-pulmonary pressure -intrapleural pressure is equal to intrapulmonary pressure -intrapulmonary pressure is lower than trans -pulmonary pressure intrapulmonary pressure is higher than atmospheric pressure

intrapleural pressure is equal to intrapulmonary pressure Correct Intrapleural pressure (Ppul) is the gas pressure within the pleural cavity, while intrapulmonary pressure (Pip) is the gas pressure within the alveoli. Normally Ppul is less than Pip to maintain lung expansion. If Ppul exceeds Pip, then the lungs collapse.

Hemoglobin -uses ATP to move oxygen from blood to body cells. has five subunits. -is the site of cellular respiration. -is found in blood plasma. -is a protein that can bind four molecules of oxygen.

is a protein that can bind four molecules of oxygen

What is the period during the cardiac cycle when the valves leading to and from the ventricles are completely closed and blood volume in the ventricles remains constant as the walls contract?

isovolumetric contraction phase Correct The prefix -iso means "equal," so during any isovolumetric stage the volume does not change.

Which of the following helps to protect against tracheal obstruction. -carina of the trachea -trachealis muscle -larynx -tracheal cartilage

larynx Correct The larynx is superior to the trachea in the respiratory tract. The laryngeal opening (glottis) is covered by the epiglottis during swallowing, normally preventing ingested materials from passing into the trachea.

Failure in a particular structure of the heart tends to cause a backup of blood in the lungs, known as pulmonary congestive heart failure. Failure of which structure of the heart would lead to such a backup? -pulmonary semilunar valve -right atrium -left ventricle -right ventricle

left ventricle Correct Failure in the left ventricle can cause increased blood hydrostatic pressure in the lungs, causing fluid buildup in the alveoli.

Which net pressure draws fluid into the capillary?

net osmotic pressure Correct Yes, the proteins exert colloid osmotic pressure, which draws fluid into the capillary.

Phagocytes are unable to adhere to bacteria that have external capsules concealing their membrane carbohydrates. Our immune system gets around this problem by coating such pathogens with __________.

opsonins Correct Opsonins are complement proteins or antibodies; both provide "handles" to which phagocyte receptors can bind. Any pathogen can be coated with opsonins, a process called opsonization ("to make tasty"), which greatly accelerates phagocytosis of that pathogen.

What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries?

osmotic pressure in capillary (OPc) Correct Osmotic pressure is based on the concentration of dissolved materials that attract water across a membrane. The osmotic pressure in a capillary (OPc) is the force drawing fluid into the blood at the venous end.

Which of the following is not a physical factor that influences pulmonary ventilation? -partial pressure of oxygen in the air -alveolar surface tension -airway resistance -lung compliance

partial pressure of oxygen in the air Correct Pulmonary ventilation is affected by pressure of air in various respiratory structures. Partial pressures of individual gases in the air affect the diffusion and dissolving of these gasses into and out of the blood.

The antivenom used to treat a venomous snake bite is an antibody produced in an animal such as a horse. Suppose these antibodies are injected into a patient who has been bitten by a venomous snake. How would you classify the resulting humoral immunity?

passive immunity, artificially acquired Correct The immunity to venom (usually short lived--the protection ends once the antibodies are naturally degraded by the body) is passive because the patient did not produce the antibodies, and it is artificially acquired since it was injected during a medical procedure.

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

passive, artificial immunity Correct Passive immunities are conferred when antibodies are given to an individual. Artificially acquired immunity occurs when humans intervene to confer immunity.

Which of the following is an organ shared by the respiratory system and the digestive system? -pharynx -trachea -larynx -esophagus

pharynx Correct The funnel-shaped pharynx connects the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly. Commonly called the throat, the pharynx is the site where our respiratory pathway, from nose to larynx, crosses the digestive pathway, from mouth to esophagus.

During which of these stages are the aortic and pulmonary valves open?

phase 2b Correct During phase 2b, the pressure in the ventricles exceeds that of the aorta and pulmonary trunk, so their valves open and allow blood to be ejected.

Inspiratory neurons send information to the diaphragm via what nerve? phrenic nerve intercostal nerves glossopharyngeal nerve vegus nerve

phrenic nerve Correct Yes, the phrenic nerve innervates the diaphragm. Stimulation causes the diaphragm to contract (increasing volume and decreasing pressure), thus causing inspiration.

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 Correct More blood returning to the heart would increase the volume of blood in the ventricles at the end of their filling phase (called end diastolic volume, or EDV). A larger EDV results in greater stretching of the myocardium, or a greater preload. Stretching (lengthening) the contractile cells brings them closer to their optimal length, allowing them to produce more force when stimulated to contract. The stronger contraction results in a larger stroke volume, and therefore a larger cardiac output.

Cardiac tamponade results in ineffective pumping of blood by the heart. This is because the excessive amount of fluid in the pericardial cavity will ______. -prevent the visceral layer of the serous pericardium from properly surrounding the heart -prevent the heart from filling properly with blood -prevent proper oxygenation of the blood -interfere with the ability of this fluid to lubricate the serous membranes

prevent the heart from filling properly with blood Correct The heart is wrapped by a double-walled sac called the pericardium. The pericardial cavity lies between the parietal and visceral layers of the serous pericardium. It is filled with a very small amount of serous fluid. If additional fluid fills the pericardial space, it adds pressure on the outside of the heart, preventing it from filling normally.

Hypercalcemia could cause ________.

prolonged T wave. Correct The T wave on an ECG tracing represents ventricular repolarization. Repolarization requires the net efflux of K+ ions. Recall that changes in normal concentrations of ions (like Ca2+) in the plasma can affect the ability of other ions to move in and out of the cell.

The colloid osmotic pressure in the capillary is caused by __________.

proteins in blood Correct Yes, the non-diffusible proteins in the plasma exert the colloid osmotic pressure, which pulls fluid into the capillary.

Which receptors inhibit inspiration during hyperinflation of the lungs? -hypothalamic receptors irritant receptors pulmonary stretch receptors -peripheral chemoreceptors

pulmonary stretch receptors Correct Yes, inspiration stimulates the pulmonary stretch receptors (PSRs), which send input to the respiratory centers, inhibiting further inspiration.

Which type of chemical induces fever?

pyrogens Correct Pyrogens target neurons in the hypothalamus to increase the set point for thermoregulation, raising body temperature above normal (37°C).

The presence of an incompetent tricuspid valve would have the direct effect of causing ______. -reduced efficiency in the delivery of blood to the lungs -reduced efficiency in the delivery of blood to the myocardium -reduced efficiency in the delivery of blood from the lungs to the heart -reduced efficiency in the delivery of blood from the head to the heart

reduced efficiency in the delivery of blood to the lungs Correct The tricuspid valve separates the right atrium and the right ventricle. It must remain tightly closed during ventricular contraction so blood can be pumped out of the ventricle and into the pulmonary arteries.

Which of the following would take the longest time to regulate blood pressure?

renal regulation Correct Renal mechanisms mediate the long-term control of blood pressure by counteracting fluctuations in blood pressure by altering blood volume. For example, if blood pressure is too low, more water will be reabsorbed to the blood from the kidney, thus increasing blood volume and blood pressure

This lung CANNOT be directly measured using a spirometer -tidal volume -residual volume -inspiratory reserve volume -expiratory reserve volume

residual volume Residual volume refers to the amount of air left in the lungs after a tidal expiration

A homeostatic control mechanism controls respiration. What acts as the effector(s) in this system? -peripheral chemoreceptors respiratory muscles central chemoreceptors medulla oblongata

respiratory muscles Correct Yes, the respiratory muscles change the volume of the thoracic cavity (and thus the pressure), resulting in inspiration and expiration.

Which of the following arterial blood levels is the most powerful respiratory stimulant? -rising CO2 levels -arterial pH -low CO2 level -low O2 level

rising CO2 level Correct Of all the chemicals influencing respiration, CO2 is the most potent and the most closely controlled. An elevation of only 5 mmHg in arterial PCO2 doubles alveolar ventilation, even when arterial O2 levels and pH haven't changed. When PO2 and pH are below normal, the response to elevated PCO2 is even greater. On the other hand, arterial PO2 must drop substantially, to at least 60 mmHg, before O2 levels become a major stimulus for increased ventilation.

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

self-antigens Correct Due to negative selection during maturation, T cells do not recognize self-antigens.

What stimulates increased respiration at the beginning of exercise? -decreased plasma oxygen levels -increased hydrogen ion levels -sensory input from receptors in joints, neural input from the motor cortex, and other factors -increased plasma carbon dioxide levels

sensory input from receptors in joints, neural input from the motor cortex, and other factors Correct Yes, at the beginning of exercise, blood gases have not changed; thus, other factors such as anticipation of exercise contribute to the increase in respiration.

If the compliance of the thoracic wall is decreased, ______. -the intrapleural pressure would not decrease normally during inhalation -the intrapulmonary pressure would remain lower than the atmospheric pressure -the airway resistance would be decreased -None of the listed response is correct

the intrapleural pressure would not decrease normally during inhalation Correct As the size of the thoracic cavity increases, so does its volume. This causes intrapleural pressure to go below atmospheric pressure so that air (gases) can move into the lungs during inspiration. If the thoracic cavity cannot change its size (volume), then intrapleural pressure will not decrease and normal air movement will not occur.

Internal and external respiration depends on several factors. Which of the following is NOT an important factor in gas exchange? -the molecular weight of the gas -available surface area -partial pressure of the gases -rate of blood flow through the tissue

the molecular weight of the gas Correct Yes, molecular weight is not an important factor in gas exchange.

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

the pH of the blood Correct Although the blood is usually sterile, the slightly alkaline pH does not prohibit pathogen growth.

What structure in the intrinsic cardiac conduction system determines heart rate? -the cardiac nerve -the sinoatrial (SA) node -the vagus nerve -the atrioventricular (AV) node

the sinoatrial (SA) node Correct The SA node is composed of pacemaker cells that initiate and set the initial pace, or the sinus rhythm, of the heartbeat.

T cells achieve self-tolerance in the __________.

thymus Correct T cells are "educated" (go through a rigorous selection process) as they mature in the thymus; their goal is to become immunocompetent and self-tolerant. A self-tolerant T lymphocyte will not react to self-antigens so that it does not attack the body's own cells.

Which lymphoid organ(s) serve(s) as the site where T lymphocytes become immunocompetent T cells?

thymus gland Correct The thymus gland is the site where T lymphocyte precursors mature to become immunocompetent T lymphocytes.

Which volumes are combined to provide the inspiratory capacity? -expiratory reserve volume (ERV) and residual volume (RV) -tidal volume (TV), inspiratory reserve volume (IRV), and expiratory reserve volume (ERV) -tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and residual volume (RV) -tidal volume (TV) and inspiratory reserve volume (IRV)

tidal volume (TV) and inspiratory reserve volume (IRV) Correct The inspiratory capacity, which is the total amount of air that can be taken into the lungs after a normal relaxed exhalation, is equal to the tidal volume (TV) plus inspiratory reserve volume (IRV).

Which of the following is NOT a function of the lymphatic system?

to participate in gas exchange at capillaries Correct While the lymphatic system does have a function at capillaries, it does not have to do with gas exchange.

Which of the following is NOT an important source of resistance to blood flow?

total blood volume Correct Total blood volume is not an important source of resistance to blood flow. However, blood volume does have a direct effect on blood pressure.

Using the same graph as in Part A, what is the average number of oxygens bound to hemoglobin at a saturation of 50%? -two -three -four -one

two Correct Binding of oxygen to an individual hemoglobin protein occurs at one oxygen per hemoglobin representing 25% saturation; two oxygens per hemoglobin, 50%; three oxygens per hemoglobin, 75%; and four oxygens per hemoglobin, 100% saturation. If an average of two oxygens are bound in all hemoglobins collectively, there is 50% saturation, shown at a blood PO2PO2 of 25 mm of Hg.

Which of the following form successively larger vessels that carry blood toward the heart?

veins Correct Veins carry blood toward the heart and so are said to "join," "merge," and "converge" into the successively larger vessels approaching the heart.

Which of the following is mismatched?

veins: resistance vessels Correct With their large lumens and thin walls, veins are low resistance vessels that can accommodate a fairly large blood volume. Veins are called capacitance vessels and blood reservoirs because they can hold up to 65% of the body's blood supply at any time. With their small diameters, it is the arterioles that are known as resistance vessels.

At what point in the cardiac cycle is pressure in the ventricles the highest (around 120 mm Hg in the left ventricle)?

ventricular systole Correct Left ventricular systole typically produces maximum pressures of around 120 mm Hg. Provide FeedbackNext

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

voltage-gated potassium channels Correct Yes, opening of voltage-gated potassium channels causes positive potassium ions to move out of the cell. This efflux of potassium causes the cell to become more negative inside thus, repolarizing the cell.

Which of the following adrenergic receptors increase cAMP levels? α2 receptors α1 receptors β receptors

β receptors Correct Yes, these receptors are coupled to adenylate cyclase by Gs receptors that increase cAMP.

What protein involved in coagulation provides the activation for the final step in clotting? -thrombin -fibrinogen -prothrombin activator -fibrin

-thrombin Correct Thrombin catalyzes the conversion of fibrinogen into fibrin. This is the final step in coagulation.

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

-thyroid hormone Correct Yes, thyroid hormones are lipid soluble and their receptors are bound to the response elements of the DNA.

Which of the following is NOT secreted by the thyroid? -triiodothyronine -calcitonin -thyroxine -thyroid-stimulating hormone

-thyroid-stimulating hormone Correct Thyroid-stimulating hormone (TSH) is secreted by the anterior pituitary gland.

The heart is actually (one, two, or three) pumps? -one pump -two pumps -three pumps

-two pumps Correct Yes, the right side of the heart pumps to/from the lungs (pulmonary circuit) and the left side of the heart pumps to/from the rest of the body (the systemic circuit).

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. Correct This closed pressure system is important for the ventricles to be able to generate enough pressure to open the semilunar valves and eject blood from the heart.

Which of the following is NOT a vasoconstrictor?

Atrial Natriuretic Peptide Correct Atrial natriuretic peptide (ANP) decreases peripheral resistance by causing vasodilation

Which of the following hormones will lower blood pressure?

Atrial Natriuretic Peptide (ANP) Correct Atrial natriuretic peptide (ANP) is a hormone released by the atria of the heart. It stimulates the kidney to excrete more sodium and water in the urine, which decreases blood volume, leading to a reduction in blood pressure. It also causes generalized vasodilation.

What is the role of the atrioventricular bundle?

The atrioventricular bundle provides the only pathway for electrical signals to pass from the atria to the ventricles. Correct The atrial cardiac cells are not connected by gap junctions to the ventricular cardiac cells. The only means by which the electrical signals of the heart can pass from atria to ventricles is the atrioventricular bundle.

When the patient stood up, his heart rate increased. This was most likely caused by which of the following?

The baroreceptor reflex activated by blood pooling in his lower body due to gravity. Correct An incompetent aortic valve will interfere with the left ventricle's job of moving blood from the lungs to the body. Blood will accumulate in the lungs, leading to pulmonary congestion.

Refer to Focus Figure 18.2, specifically the pressure in the left atrium. Which statement best explains the second rise in atrial pressure on the line graph?

The bicuspid/mitral valve closes; blood is contained within the closed chamber, exerting pressure against the atrial wall. Correct As blood flows into the left atrium, it moves passively into the left ventricle. As the atrium contracts to squeeze remaining blood downward into the ventricle, the pressure in this chamber is reflected from this contraction by the initial rise on the left atrial-pressure graph. As blood fills the ventricle, the ventricle will eventually contract, resulting in a rise in ventricular pressure and forcing the bicuspid valve flaps to close superiorly. As the valve is now closed, the pressure rises slightly in the atrium because blood is forced against the walls of the closed chamber.

Which statement best describes the autonomic nervous system's role in regulating heart rate?

The parasympathetic division normally inhibits the heart, keeping it beating at a slower rate than it would be on its own Correct The inhibitory signals from the vagus nerve inhibit the heart rate, thus keeping the heart rate lower than it would be if the vagus nerve were severed.

Which of the following represents a correct statement about pressures at the arteriolar side of the capillary bed?

The pressures directed into the blood at the arteriolar end are OPc and HPif. Correct Two pressures force fluid into interstitial fluid, HPc pushes and OPif pulls. Two other pressures, HPif pushing and OPc pulling, move fluids into the blood.

If your core temperature becomes colder, it is more difficult for oxygen to dissociate from hemoglobin at any PO2. -True -False

True Correct A decrease in temperature increases hemoglobin's binding affinity for O2, making it more difficult to dissociate (unload) O2 from hemoglobin. This is illustrated by the leftward shift of the oxygen-hemoglobin dissociation curve.

From which structures do oxygen molecules move from the lungs to the blood? -alveoli =bronchioles -bronchi -nose -trachea

alveoli Correct Alveoli are tiny sacs in the lungs surrounded by capillaries. The alveoli are where oxygen diffuses from the lungs to the blood.

Which of the following chemicals do NOT directly trigger inflammation?

antibodies Correct Antibodies are proteins that recognize specific foreign antigens. Antibodies trigger complement reactions, which may trigger inflammation, but this is not a direct pathway.

Which of the following best describes humoral immunity?

antibodies being released in the body fluids Correct Humoral immunity refers to the presence of specific antibodies in the body fluids.

Which of the following would cause a DECREASE in cardiac output (CO)?

decreasing thyroid function (thyroxine) Correct Thyroxine increases basal metabolic rate, respiratory rate, and both heart rate and contractility.

Which of the following INCREASES stroke volume?

exercise Correct Exercise increases venous return, which would in turn increase the amount of blood in the presystolic ventricle (preload).

Which of the following are NOT correctly matched?

immediate hypersensitivity: allergic contact dermatitis Correct Allergic contact dermatitis is a delayed hypersensitivity response; it is not characterized by an immediate response. Return to Assignment

Which lung volume tends to be the largest in healthy male and female adults? -tidal volume -inspiratory reserve volume -expiratory reserve volume -residual volume

inspiratory reserve volume Correct In most healthy adults, inspiratory reserve volume is greater than tidal volume, expiratory reserve volume, and residual volume.

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. Correct Helper T cells activate B cells that are displaying antigen, causing clonal expansion. Helper T cells also activate cytotoxic T cells, which will search for and destroy infected host cells.

If the transpulmonary pressure equals zero, what will happen to the lung? -lung volume will stay the same -lungs will inflate -lungs will collapse

lungs will collapse Correct Yes, the transpulmonary pressure creates the suction that keeps the lungs inflated. When room air enters the pleural space, transpulmonary pressure is zero and the lungs deflate - this is known as a pneumothorax.

What cells make antibodies?

plasma B cells Correct Yes, the plasma B cells make antibodies in response to specific antigens.

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 Correct Yes, if there is a decreased efflux of potassium while there is a normal influx of sodium, the inside of the cell would become less negative. Thus, threshold would be reached. The ability of these autorhythmic cells to spontaneously depolarize is what results in the pacemaker potential.

Which second messenger causes the release of calcium from the endoplasmic reticulum? -cAMP -DAG -IP3 -tyrosine kinase

-IP3 Correct Yes, inositol trisphosphate releases calcium from intracellular storage sites

Which of these muscles is particularly associated with anchoring the right and left atrioventricular valves? -papillary muscles -pectinate muscles -myocardium -trabecular carneae

-Papillary Muscles Papillary muscles contract to tense the right and left atrioventricular valves via the chordae tendineae just before ventricular systole.

Which portion of the electrocardiogram represents the time during which the ventricles are in systole? -P wave -T wave -Q-T interval -QRS complex

-Q-T interval Correct The Q-T interval is the period from the beginning of ventricular depolarization through ventricular repolarization, during which the ventricles are in systole.

Before Baby A was born, she was not sending much blood to her lungs. Instead, the blood passed through the septal defect into the left atrium, which sent it to the left ventricle and to her body. But why didn't the baby die if no blood was going through her lungs? -She sent her blood out into her mother's body and through her mother's lung instead. -She as so small that the small amount of blood that did go through her lungs was enough. -She was getting her oxygen from the placenta, not from breathing -Before the last trimester, babies use anaerobic respiration, so she did not need oxygen

-She was getting her oxygen from the placenta, not from breathing Correct Before birth, Baby A was fine with an atrial septal defect. In fact, she could not have lived without one −− her heart would have worn out from trying to push blood through the collapsed lungs. Instead, she pushed blood through the umbilical artery into the placenta and picked up oxygen that diffused across from her mother's blood.

Krista's treatment will likely involve destroying or surgically removing her thyroid gland. What effect will this have on her level of TSH? -TSH will increase -it will have no effect because TSH is not secreted by the thyroid -TSH will decrease

-TSH will increase Correct Destroying or removing the thyroid gland will cause thyroid hormone levels to plummet. This will cause an increase in the secretion of TSH from the pituitary.

__________ is caused by a genetic mutation that results in the production of abnormal hemoglobin. Under low-oxygen conditions, the abnormal beta chains link together and form stiff rods that alter the shape of the RBCs. -leukopenia -polycythemia -thalassemia -sickle-cell anemia

-sickle-cell anemia Correct In sickle-cell anemia, the havoc caused by the abnormal hemoglobin, hemoglobin S (HbS), results from a change in just one of the 146 amino acids in a beta chain of the globin molecule. This alteration causes the beta chains to link together under low-oxygen conditions, forming stiff rods so that HbS becomes spiky and sharp. This, in turn, causes the red blood cells to become crescent shaped when they unload oxygen molecules or when the oxygen content of the blood is lower than normal. The stiff, deformed RBCs rupture easily and tend to jam up in small blood vessels. These events interfere with oxygen delivery, leaving the victims gasping for air and in extreme pain. Bone and chest pain are particularly severe, and infection and stroke often follow.

Which of the following hormones has intracellular receptors? -epinephrine -insulin -cortisol

-cortisol Correct Yes, cortisol is one of the lipid-soluble steroid hormones. Thyroid hormones are also lipid soluble.

Which of the following represents a difference between extrinsic and intrinsic blood clotting pathways? -One leads to the formation of prothrombin activator and the other does not. -One is faster than the other. -One involves calcium ions, while the other does not. -One can be triggered by tissue damage, while the other cannot.

-one is faster than the other. Correct The extrinsic pathway is faster than the intrinsic pathway, which has many intermediate steps.

Which of the following hormone is regulated by a neuroendocrine ("letdown") reflex?] -oxytocin -cortisol -antidiuretic hormone (ADH)

-oxytocin Correct Yes, suckling of the infant (or stretching of the uterus) increases release of oxytocin, which causes the milk let-down effect (or increased uterine contractions)

Cyclic AMP is degraded by __________. AMPadenylate cyclase G proteins phosphodiesterase protein kinase

-phosphodiesterase Correct Phosphodiesterase degrades cyclic AMP into AMP

A liver cell responds to insulin by -releasing insulin -breaking down glycogen and releasing glucose -taking in glucose and converting it to glycogen -releasing glucagon

-taking in glucose and converting it to glycogen

What is the effect of high blood pressure on cardiac output?

High blood pressure increases afterload and reduces cardiac output (CO). Correct High blood pressure does produce a resistant force to systolic contractions, thus increasing afterload and end systolic volume (ESV). If ESV increases, stroke volume decreases.

Which of the following is NOT a property of mucous membranes?

Mucus contains macrophages that attack invading pathogens. Correct Mucus itself does not typically contain macrophages.

The right tricuspid valve prevents backflow of blood from the right ventricle into the _______________. -left atrium -left ventricle -pulmonary trunk -right atrium

Right Atrium Flow from the right ventricle to the right atrium is prevented by the right tricuspid valve.

Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary

venous Correct Yes, because the hydrostatic pressure of blood (which favors filtration out of the capillary) is lowest in the venous end of the capillary.

Once collected, lymph is ultimately transported into __________.

venous circulation Correct From the terminal lymphatic ducts, lymph rejoins venous circulation via the subclavian veins.

What area in the brain sets the respiratory rhythm? -pontine respiratory group (PRG) -dorsal respiratory group (DRG) -ventral respiratory group (VRG) -hypothalamus

ventral respiratory group (VRG) Correct Yes, the VRG is the rhythm-generating center in the medulla.

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? -"Perhaps you can switch to pills and a special diet once your diabetes is under control." -"Great. Maybe your relative can give you some tips on how to manage your condition." -"I'll ask the doctor if you can try an oral pill and a low carbohydrate diet before using insulin." -"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"

-"Your relative may have Type II diabetes. People with that condition can make insulin, but their cells dont respond to it properly. Your pancreas doesn't manufacture insulin" Correct A simple explanation of the differences between Type I and Type II diabetes may help your patient to understand the importance of the prescribed insulin regimen.

Assume a person is experiencing a hemorrhage and the HPc has dropped to 23 mm Hg at the arteriole end of the capillary. Calculate net filtration pressure (NFP) at the arteriole end of the capillary.

-2 mm Hg Correct The net filtration pressure would now be negative as a result of the blood pressure drop, which would result in little or no fluid moving across capillary walls into the interstitial fluid at the arteriole end. Net filtration pressure (NFP) for the arteriole end of the capillary = (HPc + OPif) − (HPif + OPc) = (23 + 1) − (0 + 26).

Determine which ECG shows a normal sinus rhythm. -A -B -C -D

-A Correct All waves are clearly present in this ECG of a normal sinus rhythm.

Mr. Watkins's blood type was determined to be A positive. Which of the following types of blood can he receive? -A positive, A negative, O positive, and O negative. -Only A positive and O negative. -A positive but not A negative. -A positive, O positive, and AB positive.

-A positive, A negative, O positive, and O negative Correct He can safely receive A and O blood.

Which of these would be an effect of an excess of thyroid hormones? -the thyroid would swell and produce a goiter -a would release less TRH -More thyroid hormone would be produced -B would release more TSH

-A would release less TRH Correct Excess thyroid hormone would have an inhibitory effect on A. This is a negative feedback mechanism.

Which ABO blood type is considered to be the universal recipient? -AB -B -O -A

-AB Correct Type AB blood is considered to be the universal recipient because neither anti-A or anti-B antibodies (agglutinins) are present.

Hypocalcemia could be caused by the ______. -apoptosis of parathyroid cells -failure of osteoclasts to respond to PTH (parathyroid hormone/parathormone) -malfunction of the parathormone receptors in kidney tubule cells -All of the listed responses are correct.

-All of the listed responses are correct Correct Parathyroid hormone (parathormone) is secreted in response to hypocalcemia. It functions to stimulate osteoclast activity, enhances the reabsorption of calcium by the kidneys, and increases absorption of calcium ions by the intestinal mucosal cells.

Determine which of the following electrocardiogram (ECG) tracings is missing P waves but is otherwise regular. -A -B -C -D

-B Correct B illustrates a QRS complex and a T wave, but it is missing the P wave.

Which of the following scenarios could result in HDN (hemolytic disease of the newborn)? -A-positive female pregnant with a B-positive baby -B-negative female pregnant with an AB-positive baby -AB-negative female pregnant with an AB-negative baby -O-positive female pregnant with a B-positive baby

-B-negative female pregnant with an AB-positive baby Correct Hemolytic disease of the newborn (HDN) can develop when an Rh-negative mother carries an Rh-positive fetus. Unlike anti-A and anti-B antibodies, anti-Rh antibodies are not preformed (i.e., a person doesn't produce them until they've been exposed to Rh-antigens for the first time). This initial exposure can occur when the Rh-negative mother carries her first Rh-positive baby. The first such pregnancy usually results in the delivery of a healthy baby. But during this pregnancy and particularly during delivery, the mother may be sensitized by her baby's Rh-positive antigens that pass into her bloodstream. If so, she will form anti-Rh antibodies unless treated with RhoGAM during pregnancy and around the time of delivery. RhoGAM is a serum containing anti-Rh antibodies. By agglutinating the Rh factor, it blocks the mother's immune response and prevents her sensitization. If the mother is not treated and becomes pregnant again with another Rh-positive baby, her antibodies will cross through the placenta and destroy the baby's RBCs, producing the condition known as hemolytic disease of the newborn (HDN).

Choose the incompatible transfusion. -Donate type O blood to a recipient with type AB blood. -Donate type B blood to a recipient with type AB blood. -Donate type B blood to a recipient with type O blood. -Donate type A blood to a recipient with type AB blood.

-Donate type B blood to a recipient with type O blood. Correct A person with type B blood can only give blood to people of type AB and B blood. The type O recipient has anti-A and anti-B antibodies in their plasma, which would produce a transfusion reaction with the B-antigens from the type B blood.

Part complete Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones? -thyroid hormones -GH (growth hormone) -oxytocin -prolactin (PRL)

-GH (growth hormone) Correct Yes, GH stimulates IGFs from the liver. IGFs are required for the growth effect of GH on bone and skin.

Your patient has a hematocrit of 56%. You recall from your anatomy and physiology class that high hematocrits are often a sign of blood doping by athletes. However, your patient is an elderly man suffering from the flu. What is most likely accounting for his elevated hematocrit? -Your patient is on chemo and it is causing him to produce too many red blood cells. -He recently donated blood. -He is leaking blood into his abdominal cavity. -He is dehydrated from the flu.

-He is dehydrated from the flu. Correct If your patient is severely ill and not drinking enough fluids, especially if he has a fever, the ratio of cells to fluid will be shifted.

Drag and drop the labels into the appropriate blanks in the sentences. Each term will be used once.

-The semilunar valves open during the ventricular ejection phase of the cardiac cycle, allowing blood to exit the ventricles. -End diastolic volume and the first heart sound are observed during the isovolumetric contraction phase of the cardiac cycle. -The P wave and subsequent atrial contraction are evident during the ventricular filling phase of the cardiac cycle. -The dicrotic notch occurs during the isovolumetric relaxation phase of the cardiac cycle. Correct The cardiac cycle reflects a series of electrical and mechanical events; these changes can be observed on a series of graphs. The electrocardiogram (ECG) tracing reflects atrial and ventricular depolarization and repolarization. The P wave corresponds to atrial depolarization, the QRS complex to ventricular depolarization (and also atrial repolarization), and the T wave reflects ventricular repolarization. Pressure changes in the left ventricle, aorta, and left atria are correlated to changes in volume as blood moves through the four chambers of the heart; there is passive blood flow and the myocardial layer of the heart is responsible for contraction, or systole, and relaxation, or diastole. Two sets of valves—atrioventricular and semilunar—regulate blood flow and keep blood moving in a one-way direction. As these valves open and close, observe the changes in the pressure and volume graphs as well as the heart sounds that are produced.

Which of the following statements is true? -A person with type O blood produces both type A and type B antigens (agglutinogens). -A person with type AB blood produces both anti-A and anti-B antibodies (agglutinins). -Type A blood can safely be given to recipients with type B blood. -Type O blood can safely be given to recipients with type B blood.

-Type O blood can safely be given to recipients with type B blood. Correct Type O blood, which does not contain either A or B agglutinogens, will not cross react with the anti-A agglutinins found in a recipient person with type B blood.

Part complete Under normal conditions, increased levels of thyroid hormone in the blood will cause _______. -an increase in TSH levels -a decrease in TSH levels -an increase in thyrotropin releasing hormone (TRH) -no change in TSH levels

-a decrease in TSH levels Correct Increased thyroid hormone levels will inhibit the release of TSH from the pituitary.

Which of the following would result from hypoparathyroidism? -a decrease in the release of calcium from bones -an increase in calcium absorption from food -an increase in calcium ion in circulating blood -an increase in calcium absorption in the kidney tubule

-a decrease in the release of calcium from bones Correct Hypoparathyroidism leads to reduced osteoclast activity in bones. The resulting lack of calcium in the blood increases excitability of neurons and muscles, producing tingling sensations.

Which is the correct order of events for hormones activating Gs proteins? -activation of a G protein, tyrosine kinase receptor, phosphorylation of intracellular proteins -activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP -activation of G protein, binding of GTP, activation of phospholipase C, activation of DAG and IP

-activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP Correct Yes, Gs proteins are stimulatory proteins that activate cAMP.

What is the mechanism of action of lipid-soluble hormones? -increasing protein kinases -activation of genes, which increases protein synthesis in the cell -phosphorylation of intracellular proteins

-activation of genes, which increases protein synthesis in the cell Correct Yes, lipid-soluble hormones diffuse into the nucleus or they diffuse into the cytoplasm and then move into the nucleus, where they affect transcription and translation.

After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do? -directly alters protein synthesis at the ribosome -acts as a transcription factor and binds to DNA, activating a gene -activates a protein kinase -phosphorylates a protein

-acts as transcription factor and binds to DNA, activating a gene Correct Yes, then mRNA is synthesized.

Where is the thyroid gland located? -at the base of the brain near the hypothalamus -posterior to the sternum in the thoracic cavity -adjacent to the trachea in the neck -posterior to the parathyroid glands in the neck

-adjacent to the trachea in the neck Correct The thyroid is a butterfly or H-shaped gland in the anterior region of the neck just inferior to the larynx, with the lobes extending to each side of the trachea.

What tropic hormone stimulates cortisol from the adrenal gland? -adrenocorticotropic hormone (ACTH) -luteinizing hormone (LH) and follicle-stimulating hormone (FSH) growth hormone (GH) -thyroid-stimulating hormone (TSH)

-adrenocorticotropic hormone (ACTH) Correct Yes, ACTH stimulates the adrenal cortex to produce cortisol. Stress and ACTH are the main stimuli for cortisol.

Which of these cells would be most effective in the disposal of inspired microorganisms that may enter the alveoli? -alveolar macrophages -type I alveolar cells -lymphocytes in blood circulating through the lungs -type II alveolar cells

-alveolar macrophages Correct Alveolar macrophages wander freely, ingesting and destroying invading microorganisms or foreign matter.

The P wave on an electrocardiogram represents __________. -ventricular depolarization -atrial depolarization -ventricular repolarization -atrial repolarization

-atrial depolarization Correct The P wave reflects the depolarization of the atria.

Which of the cell types would secrete their product if the blood glucose level was rising, as during the digestion of a meal? -alpha cells -beta cells -pancreatic acinar cells

-beta cells Correct Beta cells secrete when the blood sugar rises. Their hormone allows body cells to take up glucose from the blood.

Erythropoietin (EPO) stimulates the developmental process shown here. What part of the body does erythropoietin (EPO) target to increase erythropoiesis? -kidneys -lungs -liver -bone marrow

-bone marrow Correct The bone marrow, specifically red marrow, is the site of blood cell production and is stimulated by erythropoietin.

The amplification of the signal from a water-soluble hormone is achieved through an increase in _______. -plasma membrane receptors -water-soluble hormone in the blood -cAMP in the cytoplasm -adenylate cyclase in the plasma membrane -phosphodiesterase in the cytoplasm

-cAMP in the cytoplasm Correct Many cAMP can be generated as a second messenger to amplify the signal in response to hormone binding.

A blow to the head may cause diabetes insipidus by ______. -triggering the hypersecretion of hypothalamic-inhibiting hormones -triggering the hyposecretion of hypothalamic-inhibiting hormones -interfering with the normal transmission of nerve impulses to the posterior pituitary -interfering with the normal transmission of nerve impulses from the posterior pituitary

-interfering with the normal transmission of nerve impulses to the posterior pituitary Correct Specialized neurons called neurosecretory cells produce anti-diuretic hormone in the paraventricular nuclei of the hypothalamus. This hormone is then transported down the axons of these neurons and stored in their axon terminals, which are located in the posterior pituitary. The hormone is released from the axon endings when associated neurons fire action potentials, and it passes down the axon to the axonal terminals.

What is the significance of the slight swelling (called a goiter) in Krista's neck? -her thyroid gland is producing but not secreting excessive amounts of thyroid hormone -the auto-antibodies of Graves' disease have caused inflammation of her thyroid gland -it is a sign that her thyroid gland is overactive -it is unrelated to her condition

-it is a sign that her thyroid gland is overactive Correct Goiters almost always occur in hyperthyroidism and result from increased cell numbers and cell size in the thyroid gland as thyroid hormone production increases.

Which heart chamber receives blood from the pulmonary veins? -right ventricle -left atrium -right atrium -left ventricle

-left atrium Correct Yes, the left atrium receives oxygenated blood from the pulmonary veins.

Which chamber pumps oxygenated blood out the aorta to the systemic circuit? -left ventricle -left atrium -right ventricle -right atrium

-left ventricle Correct Yes, the left ventricle pumps oxygenated blood out the aorta to the entire body (systemic circuit).

If a person's parathyroids are responding properly to a drop in blood calcium, which of the following should result? -bone mass and density will increase -Vitamin D levels in the blood will drop -more calcium will be present in feces -less calcium will be excreted in the urine by the kidneys

-less calcium will be excreted in the urine by the kidneys Correct The kidneys would be encouraged by PTH to retain more calcium, which would result is less calcium in the urine.

Bilirubin is released into the bloodstream as old or damaged red blood cells are broken down by macrophages. Which organ is responsible for removing bilirubin from the blood stream? -pancreas -spleen -liver -kidneys

-liver Correct As RBCs are broken down, the heme of their hemoglobin is split off from globin. Its core of iron is salvaged and stored for reuse. The balance of the heme group is degraded to bilirubin, a yellow pigment that is released into the blood. Liver cells pick up the bilirubin and in turn secrete it (in bile) into the intestine, where it is metabolized to urobilinogen. Most of this degraded pigment leaves the body in feces, as a brown pigment called stercobilin.

What cells in the body respond to glucagon by breaking down glycogen and releasing glucose? -liver cells and cells in the pancreas -muscle cells -intestinal cells -liver cells -cells in the pancreas

-liver cells

Body cells that respond to insulin include -muscle cells only -liver cells only -liver cells, as well as most other cells of the body -liver cells and muscle cells only -intesitnal cells only

-liver cells, as well as most other cells of the body

What is the most important regulatory factor controlling the circulating levels of thyroid hormone? -a circadian rhythm of release -thyrotropin-releasing hormone (TRH) -negative feedback -thyroid-stimulating hormone (TSH)

-negative feedback Correct Yes, negative feedback controls the levels of circulating thyroid hormone. If levels are high, negative feedback will decrease thyroid-stimulating hormone (TSH) (and thyrotropin-releasing hormone (TRH) to some degree), thus decreasing the thyroid hormones.

Which of the following leukocyte is not correctly matched with its function? -neutrophils: produce antibodies -basophils: inflammation -lymphocytes: immune response against viral infections -monocytes: develop into macrophage

-neutrophils: produce antibodies Correct Neutrophils are active phagocytes that ingest bacteria and some fungi. Antibodies are produced by certain types of leukocytes.

What erythrocyte production disorder results from an autoimmune disease associated with insufficient vitamin B12 absorption (step 6)? -pernicious anemia -hemorrhagic anemia -renal anemia -aplastic anemia

-pernicious anemia Correct A glycoprotein called intrinsic factor, produced by the stomach, is required to absorb adequate vitamin B12. Pernicious anemia results when the stomach does not produce adequate intrinsic factor, often because the cells that produce it are attacked by the body's immune system.

Which intracellular substance degrades cAMP, thus inactivating the response to a hormone? -protein kinase C -adenylate cyclase -phosphodiesterase -phospholipase C

-phosphodiesterase Correct Yes, phosphodiesterase is an intracellular enzyme that degrades cAMP.

What is the role of activated protein kinases? -Phosphorylate ADP to ATP. -Degrade cAMP to AMP. -Phosphorylate proteins. -Activate adenylate cyclase. -Convert ATP to cAMP by phosphorylation.

-phosphorylate proteins Correct Phosphorylation can activate different proteins causing the response of the cell to water-soluble hormone.

Water-soluble hormones affect target cells by binding to __________. -adenylate cyclase -plasma membrane receptors -cytoplasmic receptors -protein kinases -cAMP

-plasma membrane receptors Correct Water-soluble hormones bind to specific receptors in the plasma membrane, whereas steroid hormones bind to cytoplasmic receptors.

What enzyme removes unneeded clots after healing has occurred? -fibrin -thrombin -plasmin -plasminogen

-plasmin Correct As healing progresses, the clot retraction process reduces the size of the clot, while plasminogen is activated into plasmin that digests the fibrin in the clot.

Which of the following is FALSE regarding the role of platelets in hemostatic reactions? -platelets do not stick to intact endothelial cells -platelets adhere to exposed collagen fibers -platelets release chemicals that attract and bind other platelets -platelets release the only chemical factors that can initiate coagulation

-platelets release the only chemical factors that can initiate coagulation. Correct Platelet chemicals initiate the intrinsic pathway, but tissue factors released from damaged endothelium start the extrinsic pathway for coagulation in motion.

There is a note in Mr. G''s chart that he had a color flow Doppler echocardiogram done to prepare for this visit. You pull up the results on the computer. You can see that the blood is flowing up through his mitral valve during systole and that his left ventricle wall is thickened, and his left atrium is dilated. The right ventricle looks normal. His ejection fraction is 43% normal levels are 55-75% (Heart Rhythm Society, 2013). How does Mr. G's altered blood flow explain his signs and symptoms? Let's use one of the diagrams you have already labeled to explain it.

1. When LEFT VENTRICLE contracts, some blood goes up through the mitral valve into the LEFT ATRIUM . Turbulent flow through valve causes SYSTOLIC murmur, LEFT ATRIUM is over-filled and DILATED. 2. Because some blood re-entered the LEFT ATRIUM less is pumped out into AORTA - EJECTION fraction is only is only 43&. 3. Less blood enters the AORTA so SBP is LOW. Baroreceptor reflex causes INCREASED heart rate; wall of overworked left ventricle becomes THICKER 4. Because it is already partly full from the ventricle, LEFT ATRIUM accepts less blood from the LUNGS. The LUNGS over fill with fluid; resulting in DIFFICULTY breathing.

Drag and drop the items below into the correct sequence from left to right.

1st Step: Hypothalamus secretes corticotropin-releasing hormone 2nd Step: Corticotropin-releasing hormone travels through the portal system to the anterior pituitary 3rd Step: Adrenocorticotropic hormone is secreted from the anterior pituitary 4th Step: ACTH travels in the blood to the adrenal cortex 5th Step: Glucocorticoids and mineralocorticoids are secreted 6th Step: Target cells produce metabolic and renal effects Correct In the long-term stress response, stressful stimuli cause the hypothalamus to release corticotropin-releasing hormone, or CRH. CRH then travels through the hypothalamic portal system to the anterior lobe of the pituitary gland. The anterior pituitary releases adrenocorticotropic hormone, or ACTH, which travels via the blood to the adrenal gland. The adrenal cortex is the specific target for ACTH, which produces more glucocorticoids, chiefly cortisol, and mineralocorticoids, namely aldosterone. As you have seen, glucocorticoids have pronounced metabolic effects on the liver, while the mineralocorticoids target the kidney to retain more water and sodium, resulting in increased blood pressure and blood volume.

Correctly order the steps involved cellular immunity: 1.The Tc recognizes the infected host cell 2.The Tc interacts with epitope presented by MHC-I on the dendritic cell 3.The Tc secretes perforin and granzyme, causing apoptosis 4.The helper T cell activates the Tc cell

2 4 1 3

Place the following steps of phagocytosis in the order that they occur: 1.Endosome fuses with lysozome 2.Dendritic cell engulfs Rhinovirus 3.Epitopes are attached to MHC-II 4.Digestion of the Rhinovirus 5.MHC-II plus the attached epitope move to the outside of the dendritic cell

2. 1. 4. 3. 5.

Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary?

34 mm Hg Correct Yes, HPc (35 mm Hg) - HPI (1 mm Hg) = 34 mm Hg, which is the net hydrostatic pressure at the arterial end. The hydrostatic pressure of the blood is much higher at the arterial end of the capillary, thus favoring filtration.

Which of the following describes a hapten?

A hapten is a foreign molecule that becomes immunogenic when combined with body proteins. Correct Haptens trigger adaptive defenses when combined with body proteins, making them appear foreign. Examples of haptens can be found in poison ivy, animal dander, and certain drugs.

How does heart rate affect stroke volume?

A high heart rate reduces the end diastolic volume (EDV) and stroke volume (SV), because there is less time for ventricular filling. Correct A slow heart rate allows more time for ventricular filling. Conversely, a faster heart rate allows less time. The amount the heart fills during diastole (EDV) has a direct impact on stroke volume.

Examine the left side of page 1 of Focus Figure 19.1.Assume you have a U-tube with a semipermeable capillary membrane made of simple squamous epithelium separating the solutions on either side. Blood will be on the left side of the tube, and watery extracellular fluid (ECF) will be on the right side of the tube. Predict what will occur to the levels of fluids by hydrostatic pressure, the pressure of watery fluid pushing on a boundary.

A pump pushing down on the left arm of the U-tube containing blood will increase ECF fluid levels on the right side. Correct Remember that the pushing by water, or hydrostatic pressure, against a boundary can force watery fluid through a semipermeable membrane, from higher to lower pressure.

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

AV node Correct Action potentials slow down as they pass through the AV node. This gives the atria time to finish contracting before the ventricles are depolarized.

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

Activation of cytotoxic T cells by helper T cells Correct The activation of cytotoxic T cells leads down the path of cell-mediated immunity.

Which of the following statements is true?

Adaptive defenses include both humoral and cellular immunity. Correct This answer is correct. Adaptive defenses are operating optimally when both humoral and cellular immunity are working together in response to a pathogen.

Emphysema can result in an ______. -increased level of carbaminohemoglobin -increased lev el of deoxyhemoglobin -increased likelihood of the skin of Caucasians developing a slightly blue coloration -All of the listed responses are correct

All of the listed responses are correct. Correct Using your textbook, review the structure of hemoglobin and how oxygen and carbon dioxide bind. Additionally review the pathophysiology of emphysema.

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

BCR and TCR Correct Both of these molecules interact with epitopes. BCRs interact with epitopes on the whole pathogen. TRCs interact with processed epitopes when presented on MHC-II.

So why is Mr. G's mitral regurgitation causing a systolic murmur? Remember, a murmur is caused by abnormal turbulent blood flow. -Because his mitral valve leaks, when the ventricles contract, they push blood back up through it into the right atrium -Because his mitral valve leaks, when the ventricles contract, they push blood back up through it into the aorta -Because his mitral valve leaks, when the ventricles contract, they push blood back up through it into the left atrium -Because his mitral valve leaks, when the ventricles relax, they push blood back up through it into the left

Because his mitral valve leaks, when the ventricles contract, they push blood back up through it into the left atrium Correct Good work. Knowing the cardiac cycle helps explain why Mr. G's leaky mitral valve causes a systolic murmur. Let's look at the other problems it might be causing him

What causes the abnormal swishing or whooshing sound that is heard as blood regurgitates back into an atrium from its associated ventricle? -blood turbulence -aortic recoil -semilunar valve closure -pulmonary trunk expansion

Blood Turbulence

You have a patient with a very low blood pressure of 80/60 mm Hg. What are the possible consequences of this low blood pressure on capillary function?

Both A and C are corerct. (Mean arterial pressure MAP would not be high enough to adequate capillary exchange to occur & Tissues would become ischemic because of lack of adequate perfusion) Correct We need a high enough mean arterial pressure (MAP) for fluid to be pushed out of the capillaries (i.e., overcoming osmotic pressure drawing fluid back in and to ensure that oxygen and nutrients are pushed out to the tissues). Without an adequate MAP, perfusion would not be adequate to deliver oxygen and nutrients to the tissues.

Drag the hormone on the left to its correct function on the right

Corticotropin-releasing hormone: Stimulates the anterior pituitary to release ACTH Epinephrine: Increased dilation of bronchioles and heart rate Adrenocorticotropic hormone: Targets the adrenal gland to release glucocorticoids and mineralocorticoids Cortisol: Increased metabolic effects from the liver Aldosterone: Increased sodium and water absorption Correct Each of these hormones plays a distinctive role in the body. Epinephrine, along with norepinephrine, target the cardiovascular and respiratory systems, producing increases in heart rate and blood pressure, along with increased dilation of the respiratory bronchioles. Blood glucose and metabolic rate increases are also important functions of epinephrine. Corticotropin-releasing hormone and adrenocorticotropic hormone are tropins; that is, their target organs are other endocrine glands. Corticotropin-releasing hormone targets the anterior pituitary, causing the release of adrenocorticotropic hormone; this, in turn, affects the adrenal cortex to release glucocorticoids and mineralocorticoids. Lastly, cortisol and aldosterone are the chief secretions of the glucocorticoids and mineralocorticoids, respectively; cortisol targets the liver for various metabolic effects, while aldosterone impacts the kidneys, causing them to retain more sodium and water.

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

Cytotoxic T cells Correct Yes, cytotoxic T cells attack cancer cells, since they are part of cell-mediated immunity.

How do cytotoxic cells directly attack target cells?

Cytotoxic cells bind to the target cell and secrete chemicals that induce apoptosis. Correct Cytotoxic cells are able to dock with antigens on the target cell membrane. Once docked, the cytotoxic cell releases perforins and granzymes, which weaken the cell membrane and induce apoptosis.

Captain Fallowell's drop in blood pressure when standing up is most likely due to:

Decreased cardiac output due to low stroke volume. Correct His heart rate is elevated and his blood vessels are vasoconstricting, yet his blood pressure is low; stroke volume must be the factor that has decreased.

After blood becomes oxygenated. -it does not return to the heart, but goes directly to the lungs. -it returns to the heart, and is then pumped to the lungs. it does not return to the heart, but goes directly to capillaries that supply the body's cells with oxygen. -it does not return to the heart, but goes to the nose and mouth. -it returns to the heart, and is then pumped to body cells.

It returns to the heart, and is then pumped to body cells

Which type of vessel is most suited to expanding and recoiling in response to the ejection fo blood from the heart?

Elastic Artery Correct Elastic arteries absorb most of the shock when the heart ejects blood. The expansion stores energy; the recoil disperses this energy by moving blood further through the circulation.

Which of the following would NOT be a cause of edema in your patient's lower extremities?

Excess protein in the diet Correct If a patient's plasma protein, especially albumin, is too low, then his or her osmotic pressure is low. Recall that plasma proteins act as "water magnets," resisting the force of hydrostatic pressure (i.e., blood pressure) that pushes fluid out of the capillaries. Edema can be a consequence of low plasma protein.

What directly stimulates the central chemoreceptors, thus increasing respiration? -H+ (hydrogen ions) low O2 (oxygen high CO2 (carbon dioxide) high pH

H+ (hydrogen ions) Correct Yes, hydrogen ions (H+) stimulate the central chemoreceptors. CO2 is converted to H+ in the extracellular fluid of the brain.

Why does a graph of the membrane potential of living pacemaker cells never demonstrate a flat line? -Hyper-polarization of pacemaker cells triggers the opening of slow Na+ channels and starts a new slow depolarization phase. -The vagus nerve continually stimulates the pacemaker cells. -As pacemaker cells hyperpolarize, the excessive influx of K+K+ ions increases the membrane potential. -Repolarization of pacemaker cells triggers the opening of fast Ca2+Ca2+ channels, triggering another rapid depolarization.

Hyperpolarization of pacemaker cells triggers the opening of slow Na+ channels and starts a new slow depolarization phase. Correct At the end of an action potential, as repolarization and hyperpolarization occur, slow Na+ channels open, causing the membrane potential to immediately start to increase again (called the pacemaker potential), eventually triggering another action potential.

Which of the following are properly matched?

IgG: most abundant antibody Correct IgG is the most abundant class of antibodies in plasma. Additionally, IgG is the only class of antibodies that normally crosses the placenta to protect the baby in utero.

Focus your attention on the graph shown, from the left side of the Focus Figure. The percent of O2O2 saturation of hemoglobin is plotted (on the y-axis) against PO2PO2 (mm Hg) (on the x-axis). Use this graph to complete Parts A-C below. On this graph, the y-axis (the vertical edge) tells you how much O2O2 is bound to hemoglobin (Hb). At 100%, each Hb molecule has four bound oxygen molecules. The x-axis (the horizontal edge) tells you the relative amount (partial pressure) of O2O2 dissolved in the fluid surrounding the Hb. If more O2O2 is present, more O2O2 is bound. However, because of Hb's properties (O2O2 binding strength changes with saturation), this is an S-shaped curve, not a straight line. Which of the following represents a correct statement about data presented in the graph? -In blood with 30% oxygen saturation of hemoglobin, there is a PO2PO2 of ~60 mm Hg in surrounding fluid. -In blood with 60% oxygen saturation of hemoglobin, each individual hemoglobin binds ~2.5 oxygens. -Blood with three oxygens per hemoglobin represents a saturation of PO2PO2 at ~30 mm Hg. -In blood with a PO2PO2 of 30 mm Hg, the average saturation of all hemoglobin proteins is 60%.

In blood with a PO2 of 30 mm Hg, the average saturation of all hemoglobin proteins is 60%. Correct Cooperative binding of oxygen to an individual hemoglobin protein occurs with one oxygen per hemoglobin representing 25% saturation; two oxygens per hemoglobin, 50%; three oxygens per hemoglobin, 75%; and four oxygens per hemoglobin, 100% saturation. Only collectively with all hemoglobins can there be percentages in between, as seen in the S-shaped curve graph of saturation plotted against PO2PO2 of blood.

Which statement is correct? -Oxygen is released from the mitochondria as a product of cellular respiration. -Carbon dioxide diffuses from the alveoli into surrounding capillaries. In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. -As oxygen diffuses from the lungs into capillaries, blood becomes deoxygenated. -Oxygen diffuses from large blood vessels into the body's cells.

In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. Correct When oxygen diffuses from the alveoli to the surrounding capillaries, it enters a red blood cell and binds to hemoglobin.

Which of the following is an effect of epinephrine, norepinephrine, and thyroxine?

Increase contractility Correct Epinephrine, norepinephrine, and thyroxine secreted by the sympathetic nervous system directly increase contractility and heart rate, for the overall effect of increasing cardiac output. Likewise, end systolic volume would decrease with increased contractility.

A muscle that is being regularly contracted during exercise will attract blood flow by dilating arterioles. Which of these factors would contribute to this effect?

Increased Levels of carbon dioxide Correct Carbon dioxide produced in muscle respiration would be a metabolic mechanism, which would dilate local arterioles and increase blood flow.

Which of the following lowers blood pressure by reducing the sympathetic vasomotor response?

Increasing the secretion of atrial natriuretic peptide (ANP)

Baby A was scheduled for surgery to repair her atrial septal defect. The operation went well, and she is recovering nicely. Her mother wants to know whether she will need transfusions since her blood pressure was so low before the surgery. Will she need transfusions to maintain her systemic volume? -No. When she had the shunt, her body increased its blood volume to keep blood pressure up. For the rest of her life, her blood pressure will be too high. -Yes. Her body has become adapted to having low blood pressure and will not raise it up again. For the rest of her life, she will have low blood pressure. -No. Now that the shunt has been repaired, her blood is not being diverted from the systemic circuit into the pulmonary circuit, and her blood pressure should return to normal. -Yes. The shunt was causing excess blood to enter her lungs, and now that it is repaired, that excess blood has been removed.

No. Now that the shunt has been repaired, her blood is not being diverted from the systemic circuit into the pulmonary circuit, and her blood pressure should return to normal. Correct Good work! In this pediatric case, the nurse's job involves assessment, interpretation of lab results, and educating a concerned mother. Like many of us, patients often remember things much better when you present them in pictures. You have made Mrs. A feel much better, as she understands what is going on with her baby and how the treatment should help. She will be better able to identify any problems as she cares for her daughter at home.

Which way would O2O2 and CO2CO2 diffuse during internal respiration? -Both O2 and CO2 would diffuse into the systemic capillaries. -O2 would diffuse into the systemic capillaries, and CO2CO2 would diffuse into the cells. -O2 would diffuse into the cells, and CO2 would diffuse into the systemic capillaries. -O2 would diffuse into the pulmonary capillaries and CO2CO2 would diffuse into the alveoli.

O2 would diffuse into the cells, and CO2CO2 would diffuse into the systemic capillaries. Correct Yes, the PO2 would be higher in the systemic capillaries, and the PCO2PCO2 would be higher in the tissues.

Which of the following CANNOT diffuse across a capillary wall to or from the surrounding interstitial fluid?

Proteins Correct Large molecules, such as proteins, are actively transported in pinocytotic vesicles. They are too large to pass through the intercellular clefts or fenestrations, which is how smaller water-soluble molecules cross the capillary wall.

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 Correct The cytotoxic T cell uses its CD8 glycoprotein to bind to the MHC-I of an infected host cell.

Drag and drop the items below to the appropriate bin, depending if the item is associated with the short-term or long-term stress response.

Short-term stress response -activated by neural stimuli -hormone released; epinephrine -triggers the fight-or-flight response -targets the adrenal medulla Long-Term Stress Response -activated by hormonal stimuli -targets the adrenal cortex -hormone released; glucocorticoids -increased blood pressure; increased protein and fat catabolism Correct The long-term and short-term stress responses vary in their mechanisms: in the short-term response, stressful stimuli target the hypothalamus, which activates the sympathetic nervous system, ultimately impacting the adrenal medulla. The adrenal medulla releases the catecholamine hormones - epinephrine and norepinephrine - which result in many of the effects associated with the "fight or flight" mechanism. In the long-term response, stressors to the hypothalamus cause the release of corticotropin-releasing hormone, which targets the anterior pituitary gland. Adrenocorticotropic hormone travels in the blood and targets the adrenal cortex, resulting in the production of mineralocorticoids and glucocorticoids. The mineralocorticoids impact the kidney with increased sodium and water retention, while the glucocorticoids target the liver to increase production of glucose from fats and proteins, or mobilize them for energy.

The echocardiogram revealed an atrial septal defect as well as confirming the enlarged right ventricle and pulmonary trunk. Baby A's systemic blood pressure is also decreased. What is the most likely explanation? Since she has a pulmonary infection, more blood is being diverted to her lungs; this distends her pulmonary trunk and leaves less blood in the systemic circuit. -Her repeated pulmonary infections have weakened the right side of her heart, so it is enlarged. -Since blood is moving between her atria, the blood in her ventricles and arteries is staying where it is, distending those structures. -Since blood is moving from her systemic circuit into her pulmonary circuit, the pulmonary circuit is distended and the systemic circuit is low on blood.

Since blood is moving from her systemic circuit into her pulmonary circuit, the pulmonary circuit is distended and the systemic circuit is low on blood.

Which of the following is a myogenic factor that influences blood flow?

Stretch of vascular smooth muscle Correct Myogenic control of vascular smooth muscle occurs in response to the stretch of the vessel because of blood pressure fluctuations.

Mr. G has mitral regurgitation. How has this caused a systolic murmur? First of all, let's sort out what is happening during systole and diastole.

Systole -Ventricles are contracting -Blood is leaving the heart -Semilunar Valves are open -AV valves are closed -Blood is flowing through semilunar valves Diastole -Ventricles are relaxed -AV Valves are open -Blood is entering the heart -Semilunar valves are closed -Blood is flowing through AV valves

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

T cells Correct T cells are a part of the adaptive (specific) defenses against disease. They are involved in cell-mediated immunity as they defend the body against specific pathogens.

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 quickly, decreasing the heart rate. -The SA node would depolarize more quickly, increasing the heart rate. -The SA node would depolarize more slowly, reducing the heart rate. -The SA node would depolarize more slowly, increasing the heart rate. -There will be no change.

The SA node would depolarize more slowly, reducing the heart rate. Correct Diffusion of Na+ into the pacemaker cell causes a gradual depolarization of the cell membrane, called the pacemaker potential. If the rate of depolarization slows down, it will take longer for the membrane to reach threshold and trigger the next action potential, which will reduce heart rate.

Focus your attention again on Focus Figure 22.1. Focus Figure 22.1. A firefighter breathes in air normally as he enters a building following an explosion and fire. He has a meter that predicts the PO2PO2 will approximate 15 mm Hg in his tissue fluids as he actively moves about the room. Select the best statement. -The large changes in PO2 tissue environments cause only very small changes in hemoglobin O2 saturation, and no oxygen is needed. -The firefighter is at about 10% hemoglobin O2O2 saturation, and he requires an external air tank. -The firefighter's hemoglobin saturation will be about one oxygen per hemoglobin, and he will require an external air tank. -The S-shaped saturation curve of hemoglobin is flat at this PO2PO2, and O2O2 saturation doesn't change much with PO2PO2 changes in mm Hg.

The firefighter's hemoglobin saturation will be about one oxygen per hemoglobin, and he will require an external air tank. Correct An O2O2 saturation of hemoglobin of ~25% is insufficient for the firefighter moving about the room, and he should use external oxygen.

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. Correct Your response is succinct and accurate, which are good skills for a clinician.

Now that you have reviewed normal blood flow, why does a patient with left-sided heart failure have a low systolic blood pressure? -The left side of the heart contains the ventricles, so it controls blood pressure. -The left side of the heart pumps blood into the body, so when it fails, less blood will be pumped into the arteries. -The left side of the heart does not directly move blood into the body, but when it fails, the right side will also fail, and that will decrease blood pressure out in the body. -The left side of the heart receives blood from the body, so when it fails, blood will build up in the blood vessels.

The left side of the heart pumps blood into the body, so when it fails, less blood will be pumped into the arteries. Correct Since the left ventricle is the one responsible for pumping blood into the arteries, it makes sense that left-sided heart failure would reduce the amount of blood sent into the arteries and therefore the systolic blood pressure. That is not what brought Mr. G to the doctor, though.

Mr. G talks in short bursts with frequent breaths. He tells you he used to feel breathless when he was walking, but now he has been having more and more trouble breathing even when he is lying down at night. When you listened to his lungs you heard fluid in them. Could this be due to his heart failure, or is it another problem? -The left side of the heart receives blood from the lungs and pumps it out to the body, so if it fails, blood will remain in the lungs. -If the left side of the heart fails, it will not pump enough blood to the body, and that means less blood will reach the right side of the heart and be sent to the lungs. -The left side of the heart does not have anything to do with the lungs, but if it fails, the right side is going to fail too, and then circulation through the lungs will decrease. -The left side of the heart pumps blood to the lungs, so if it fails, circulation in the lungs will decrease.

The left side of the heart receives blood from the lungs and pumps it out to the body, so if it fails, blood will remain in the lungs. Correct Difficulty breathing, or dyspnea, is a common side effect of left-sided heart failure. It happens when the left side of the heart is not able to move blood out of the lungs to the body fast enough. The right side of the heart, meanwhile, is pumping more blood into the lungs. As a result, the lung capillaries are overfilled, the pulmonary blood pressure is increasing, and more fluid is forced out of the capillaries into the lungs. Mr. G does not feel so bad during the day because when he stands or sits, gravity pulls a lot of his blood into his legs. When he lies down at night, though, much of that blood moves into his chest, and the amount of fluid going into his lungs increases. He may wake up with the feeling that he is drowning −− which is accurate, in a way!

When blood glucose levels are low -The pancreas releases insulin, which eventually causes blood glucose levels to increase. -The pancreas releases glucagon, which eventually causes blood glucose levels to increase. Liver cells convert more glucose to glycogen. -The pancreas releases glucagon, which eventually causes blood glucose levels to decrease. -The pancreas releases insulin, which eventually causes blood glucose levels to decrease.

The pancreas releases glucagon, which eventually causes blood glucose levels to increase.

How would the partial pressures of O2O2 and CO2CO2 change in an exercising muscle? -The partial pressure of O2O2 would increase, and the partial pressure of CO2CO2 would decrease. -The partial pressures of O2O2 and CO2CO2 would remain unchanged. -The partial pressure of O2O2 would decrease, and the partial pressure of CO2CO2 would increase.

The partial pressure of O2O2 would decrease, and the partial pressure of CO2CO2 would increase. Correct Yes, cells use O2O2 and produce CO2CO2 during cellular respiration to produce ATP. Exercising muscles need more ATP.

Which of the following descriptions accurately describes Boyle's law? -How well a gas dissolves in a liquid such as blood depends on both its partial pressure and its solubility. -The pressure of gas in your lungs is inversely proportional to the volume in your lungs. -The partial pressure of a gas in the air you breathe in is equal to the total atmospheric pressure times the fractional concentration of the gas.

The pressure of gas in your lungs is inversely proportional to the volume in your lungs. Correct Yes, Boyle's Law describes how air moves into and out of the lungs during inspiration and expiration. By changing the volume of the thoracic cavity, the pressure changes in the lungs. Increasing volume of the thoracic cavity leads to a decreased pressure, causing air to flow into the lungs (down its pressure gradient) and thus causing inspiration.

Which statement correct regarding the ventricles? -The right ventricle empties into the pulmonary trunk -the left ventricles empties into the pulmonary circuit -the right ventricle forms a complete circle in cross section -the left ventricle has a thinner wall than the right ventricle

The right ventricle empties into the pulmonary trunk Flow from the right ventricle to the right atrium is prevented by the right tricuspid valve.

Part complete How is the adaptive third line of defense able to target specific pathogens?

The third line of defense responds to antigens on the pathogen. Correct All foreign invaders of the body present antigens that can activate the adaptive immune response. The adaptive immune response can then produce antibodies that bind to the antigens to help identify, disable, and destroy the pathogens.

Mr. G's online file also has the results of his recent blood tests. The only thing that looks abnormal is something called ANP - atrial natriuretic peptide. It is elevated. Why would this hormone be elevated in Mr. G, and what is it doing to him? -his hormone comes from damaged ventricles and indicates that Mr. G's left ventricle is beginning to fail. -This hormone comes from the atria and causes the atria and causes the body to release ore K+ in the urine protecting Mr. G against a possibly fatal arrhythmia. -This hormone is the normal secretion from heart muscle cells, and it is elevated because Mr. G's left ventricle is larger. =This hormone comes from the overstretched atrium and makes Mr. G lose more Na+ and water in his uring, lowering blood volume reducing the load on the atrium. -This hormone controls sodium and water retention and is secreted by the adrenal cortex as part of the central response that raises blood pressure.

This hormone comes from the overstretched atrium and makes Mr. G lose more Na+ and water in his urine, lowering blood volume reducing the load on the atrium. Correct Even though they both had rheumatic fever, you can see that Mr. G and Mr. V have completely different heart problems −− one has a leaky valve, and the other a partly blocked valve; one has a systolic murmur, and the other a diastolic murmur. This sort of thing will really confuse you unless you work it out carefully step by step!

Lymph arrives at the lymph nodes via afferent lymphatic vessels.

True Correct Afferent vessels deliver lymph to the lymph node. The lymph then filters through the subcapsular sinus of the node, then into a number of smaller sinuses that cut through the node's cortex and lead into the medulla. Eventually, lymph exits the node at the hilum as it is carried away by efferent vessels.

Which layer of the typical blood vessel is constructed from simple squamous epithelium?

Tunica Intima Correct The tunic intima of blood vessels, like the endocardium of the heart, is made of simple squamous epithelium.

Which layer of the typical vessel can be regulated to constrict or dilate the lumen?

Tunica Media Correct The tunica media consists of smooth muscle that is regulated by the sympathetic nervous system. It is used to regulate the diameter of the lumen.

In children with infant respiratory distress syndrome (IRDS), the walls of the alveoli cling to each other and make them difficult to inflate. It is common in babies born prematurely. What cells in these infants are NOT fully developed and are NOT doing their job? -endothelial cells of alveolar capillaries -alveolar macrophages -type II alveolar cells -type I alveolar cells

Type II Alveolar Cells Correct Type II alveolar cells secrete a detergent-like surfactant that lessens the surface tension on the alveolar walls, preventing them from sticking to each other. Infants with IRDS can be treated until their cells produce adequate surfactant.

During exercise, cardiac output may increase by more than 170%% to meet the body's increased O2O2 demands. This increase in cardiac output increases blood pressure. But the accompanying increase in arterial pressure is relatively small—only about 40%%. What limits this increase in blood pressure so that it doesn't reach dangerously high levels during exercise?

Vasodilation causes arterial diameter to increase in the exercising skeletal muscle. Correct During exercise, total peripheral resistance decreases. This is primarily due to an increase in the diameters of arterioles supplying the exercising muscles. Vasodilation of the blood vessels increases blood flow, providing the oxygen and nutrients necessary to support increased muscle metabolism. In addition, vasodilation of the arterioles in the skin also allows for greater blood flow to the skin for evaporative cooling.

What is happening during the "pause" phase when the heart is resting (relaxing)? -Ventricles are filling -Valves are closing -Ventricles are contraction -Atria are contractin

Ventricles are filling

Suppose a patient develops a myocardial infarction that disables the sinoatrial node. Would the heart still pump blood to the aorta and the pulmonary trunk? -No, because there will be no contraction of the atria. -Yes, because the ventricles will depolarize on their own without nodal stimulation at a rate of 50 times per minute. -No, because there would be no more connection between the atrioventricular node and the bundle branches. -Yes, because the atrioventricular node will still stimulate ventricular systole.

Yes, because the atrioventricular node will still stimulate ventricular systole. Correct The atrioventricular node spontaneously depolarizes similarly to the sinoatrial node, but more slowly. It can lead to the ventricles pumping blood to the aorta and pulmonary trunk around 50 times per minute.

Which of the following would induce the loss of oxygen from the hemoglobin and the blood? -decreases in plasma carbon dioxide -a drop in blood pH increase in hemoglobin that has -oxygen bound to it already -a decrease in blood temperature

a drop in blood pH Correct The pH in blood tends to drop when plasma reacts with carbon dioxide, a common condition in tissue. This pH drop causes weakening of the Hb-O2 bond, a phenomenon called the Bohr effect.

Which specific type of cell produces antibodies?

activated plasma cells Correct When activated by the presence of antigens, B lymphocytes proliferate into plasma cells. Plasma cells generate antigen-specific antibodies.

Costanza was picking grapes in her father's arbor when she felt a short prickling pain in her finger. She ran crying to her father, who removed an insect stinger and calmed her with a glass of lemonade. Twenty minutes later Costanza's finger was red, swollen, and throbbing where she had been stung. What type of immune response was she exhibiting?

acute, type I hypersensitivity reaction Correct Immediate hypersensitivities, also called acute or type I hypersensitivities, are simply what most of us would call allergies. An allergen is an antigen that causes an allergic reaction. Allergic reactions, mediated by IgA antibodies, begin within seconds after contact with the allergen and last about half an hour. Since histamines (and other inflammatory chemicals) induce the inflammatory response typical of allergies, antihistamines are most commonly used to treat this condition.

Which of the following is/are part(s) of the respiratory zone structures? -alveoli -terminal bronchioles -trachea -primary bronchi

alveoli Correct Alveoli are thin-walled air sacs that are the sites of gas exchange. Along with the respiratory bronchioles and alveolar ducts, the alveoli make up the respiratory zone.

Which of the following behaviors would most likely result in an increased alveolar ventilation rate as compared to that of normal breathing? -breathing rapidly into a paper bag -breathing slowly into a paper bag -rapid shallow breathing -slow deep breathing

slow deep breathing Correct Slow breathing provides adequate time for gases to pass into the alveoli, while breathing deeply increases the number of alveoli being utilized. The combination of these factors increases effective ventilation, or alveolar ventilation rate.

Which of the following mechanisms is NOT used to propel lymph through lymphatic vessels?

small, heart-like pumps . Correct There is no direct pumping action in the lymphatic system. Movement of fluid depends on factors such as gravity and body movement.

Consider the following characteristics of the cells found in muscle tissue. Which feature is shared by both cardiac muscle and skeletal muscle? -striations -triads -intercalated discs -branched cells

striations Correct Since both cardiac and skeletal muscles possess arrangements of motor proteins in regularly arrayed sarcomeres, they both display the banding known as striations.

During inhalation, -the diaphragm and rib muscles contract -the diaphragm relaxes -the volume of the thoracic cavity decreases -oxygen molecules move into the lungs, and carbon dioxide molecules move out of the lungs -air moves up the trachea

the diaphragm and rib muscles contract Correct The contraction of these muscles causes air to enter the lungs.

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 Correct Yes, the flow of positive ions from the autorhythmic cells (or adjacent cells) brings the membrane to threshold initiating depolarization of the contractile cell.