Phys questions Ch 20, 22, 35, 69 CARDIO 2
B) Increased right atrial pressure During compensated heart failure, many factors combine to increase cardiac output so it returns to normal. The kidneys decrease their urinary output of sodium and water to increase the blood volume. This action, when combined with a depressed cardiac output curve, will increase right atrial pressure. Mean systemic filling pressure increases (not decreases), and the venous return of blood back toward the heart thus increases right atrial pressure. Heart rate is normal, and sweating and dyspnea are absent in the chronic stages of compensated failure
111. What is normally associated with the chronic stages of compensated heart failure? Assume the patient is resting A) Decreased mean systemic filling pressure B) Increased right atrial pressure C) Increased heart rate D) Sweating E) Dyspnea
E) Increased mean pulmonary filling pressure In unilateral left heart failure, the kidneys retain sodium and water and thus increase blood volume and the pulmonary veins, in turn, become congested. Therefore, mean pulmonary filling pressure, pulmonary wedge pressure, and left atrial pressure increase. In contrast, in right heart failure, right atrial pressure increases and edema of the lower extremities, including the feet and ankles, occurs.
103. What normally occurs in a person with unilateral left heart failure? A) Decreased pulmonary artery pressure B) Decreased left atrial pressure C) Decreased right atrial pressure D) Edema of feet E) Increased mean pulmonary filling pressure
A) Increased formation of angiotensin II In compensated heart failure, an increased release of angiotensin II also occurs, which causes direct renal sodium retention and also stimulates aldosterone secretion that will, in turn, cause further increases in sodium retention by the kidneys. Because of the low arterial pressure that occurs in compensated heart failure, the sympathetic output increases. One of the results is a sympathetic vasoconstriction (not vasodilation) of the afferent arterioles of the kidney. This decreases the glomerular hydrostatic pressure and the glomerular filtration rate, resulting in an increase in sodium and water retention in the body. The excess sodium in the body will increase osmolality, which increases the release of antidiuretic hormone, which causes renal water retention (but not sodium retention).
104. What normally causes renal sodium retention during compensated heart failure? A) Increased formation of angiotensin II B) Increased release of atrial natriuretic factor C) Sympathetic vasodilation of the afferent arterioles D) Increased glomerular filtration rate E) Increased formation of antidiuretic hormone (ADH)
C) Administer furosemide During acute pulmonary edema, the increased fluid in the lungs diminishes the oxygen content in the blood. This decreased oxygen weakens the heart even further and also causes arteriolar dilation in the body. This results in increases in venous return of blood to the heart, which cause further leakage of the fluid in the lungs and further decreases in oxygen content in the blood. It is important to interrupt this vicious circle to save a patient's life. This can be interrupted by placing tourniquets on all four limbs, which effectively removes blood volume from the chest. The patient can also breathe oxygen, and a bronchodilator can be administered. Furosemide can be administered to reduce some of the fluid volume in the body and especially in the lungs. One thing you do not want to do is infuse whole blood or an electrolyte solution in this patient because it may exacerbate the pulmonary edema that is already present.
105. Which intervention would normally be beneficial to a patient with acute pulmonary edema? A) Infuse a vasoconstrictor drug B) Infuse a balanced electrolyte solution C) Administer furosemide D) Administer a bronchoconstrictor E) Infuse whole blood
B) Increased atrial natriuretic factor release Several factors cause sodium retention during heart failure, including aldosterone release, decreased glomerular filtration rate, and an increased angiotensin II release. A decrease in mean arterial pressure also results in decreases in glomerular hydrostatic pressure and causes a decrease in renal sodium excretion. During heart failure, blood volume increases, resulting in an increased cardiac stretch. In particular, the atrial pressure increases, causing a release of atrial natriuretic factor, resulting in an increase in renal sodium excretion.
108. Which of the following occurs during heart failure and causes an increase in renal sodium excretion? A) Increased aldosterone release B) Increased atrial natriuretic factor release C) Decreased glomerular filtration rate D) Increased angiotensin II release E) Decreased mean arterial pressure
A) Increased right atrial pressure In unilateral right heart failure, the right atrial pressure increases and the overall cardiac output decreases, which results in a decrease in arterial pressure and urinary output. However, left atrial pressure does not increase but in fact decreases.
110. Which condition normally accompanies acute unilateral right heart failure? A) Increased right atrial pressure B) Increased left atrial pressure C) Increased urinary output D) Increased cardiac output E) Increased arterial pressure
C) Helper T cells CD4 helper T cells recognize the MHC class II + peptide on the presenting cell. CD8 T cells recognize the MHC class I + peptide on the infected cell.
CD4 is a marker of which of the following? A) B cells B) Cytotoxic T cells C) Helper T cells D) An activated macrophage E) A neutrophil precursor
Ch 20 start
Chapter 20: Cardiac Output, Venous Return, and Their Regulation
Ch 22 Start
Chapter 22: Cardiac Failure
Ch23
Chapter 23: Heart Valves and Heart Sounds; Valvular and Congenital Heart Defects
27 start
Chapter 27: Glomerular Filtration, Renal Blood Flow, and Their Control
ch 69 start (with biochem)
Chapter 69: Lipid Metabolism
Cross plasma membranes
Cholesterol, a precursor to many steroid hormones, allows them to:
Cytotoxic T lymphocytes Allograft rejection occurs primarily through the actions of cytotoxic T cells. T-helper cells promote this reaction but are not the effector cells. Both macrophages and dendritic cells may present antigen that promotes the immune response, but the key effector cells are cytotoxic T cells.
Chronic allograft rejection results primarily from the actions of what effector cell type?
This patient has a resting cardiac output of 4 L/ min, and his cardiac reserve is 300% of this resting cardiac output or 12 L/min. This gives a total maximum cardiac output of 16 L/min. Therefore, the cardiac reserve is the percentage increase that the cardiac output can be elevated over the resting cardiac output.
If a 21-year-old male patient has a cardiac reserve of 300% and a maximum cardiac output of 16 L/min, what is his resting cardiac output?
C. 12 This problem concerns the Fick principle for determining cardiac output. The formula for cardiac output is oxygen absorbed per minute by the lungs divided by the arterial-venous oxygen difference. In this problem, oxygen consumption of the body is 240 ml/min, and in a steady-state condition, this would exactly equal the oxygen absorbed by the lungs. Therefore, by inserting these values into the equation, we see that the cardiac output will equal 12 L/min.
If a patient has an oxygen consumption of 240 ml/min, a pulmonary vein oxygen concentration of 180 ml/L of blood, and a pulmonary artery oxygen concentration of 160 ml/L of blood units, what is the cardiac output in L/min?
Ch 35 start
Immunity and allergy 35
Lipoprotein(a)
It has been reported that high concentrations of which of the following correlate with an increased risk of coronary artery disease, even in patient in whom the lipid profile is otherwise normal, as they cannot be converted to active plasmin?
A) A = polycationic; B = neutral; C= polyanionic For any given molecular radius, positively charged molecules (cations) are filtered more readily than negatively charged molecules (anions) because negative charges on the proteins of the basement membrane and podocytes of the glomerular capillaries tend to repel large negatively changed molecules (e.g., polycationic dextrans, curve C). Large positively charged molecules (curve A) are filtered more readily
Lines A, B, and C on the figure above show the relative filterability by the glomerular capillaries of dextran molecules as a function of their molecular radius and electrical charges. Which lines on the graph best describe the electrical charges of the dextrans? A) A = polycationic; B = neutral; C= polyanionic B) A = polycationic; B = polyanionic; C = neutral C) A = polyanionic; B = neutral; C = polycationic D) A = polyanionic; B = polycationic; C = polycationic E) A = neutral; B = polycationic; C = polyanionic F) A = neutral; B = polyanionic; C = polycationic
Diabetes mellitus
Of the major risk factors for the development of atherosclerotic cardiovascular disease (ASCVD) such as sedentary lifestyle, obesity, cigarette smoking, diabetes mellitus, hypertension, and hyperlipidemia, which one, if present, is the only risk factor in a given patient without a history of having had a myocardial infarction that requires that the therapeutic goal for the serum LDL cholesterol level be < 100mg/dL?
steatorrhea MTP is required for the synthesis of nascent chylomicrons and VLDL. With no MTP, lipids accumulate in the intestinal epithelial because it can not be transported out of the lumen (by chylomicrons). This leads to fatty stools (steatorrhea). Less MTP will also lead to less VLDL which leads to less IDL and less LDL.
Patient with no microsomal tryglyceride transfer protein (MTP) will have
true
Squalene monooxygenase is considered a mixed function oxidase because it catalyzes a reaction in which only one of the oxygen atoms of O2 is incorporated into the organic substrate
HMG-CoA HMG-Coa -> Mevalonic acid is rate limiting and committing step catalyzed by HMG-COA reductase
Statins lower serum cholesterol by inhibiting the major rate limiting step of cholesterol what metabolite will build up?
C) Breathing against a negative pressure Several factors can cause the cardiac output to shift to the right or to the left. Among those are surgically opening the chest, which makes the cardiac output curve shift 4 mm Hg to the right, and severe cardiac tamponade, which increases the pressure inside the pericardium, thus tending to collapse the heart, particularly the atria. Playing a trumpet or positive pressure breathing tremendously increases the intrapleural pressure, thus collapsing the atria and shifting the cardiac output curve to the right. Breathing against a negative pressure will shift the cardiac output curve to the left
What normally causes the cardiac output curve to shift to the left along the right atrial pressure axis? A) Surgically opening the chest B) Severe cardiac tamponade C) Breathing against a negative pressure D) Playing a trumpet E) Positive pressure breathing
B) Atrioventricular (A-V) fistula Cardiac output increases in several conditions because of increased venous return. A-V fistulae also cause a decreased resistance to venous return, thus increasing cardiac output. Cardiac output decreases in patients with hypovolemia, severe aortic regurgitation, and polycythemia. The hematocrit level is high in polycythemia, which increases resistance to venous return.
What is normally associated with an increased cardiac output? A) Increased parasympathetic stimulation B) Atrioventricular (A-V) fistula C) Decreased blood volume D) Polycythemia E) Severe aortic regurgitation
D) Moderate anemia Decreased cardiac output can result from a weakened heart or from a decrease in venous return. Increased venous compliance decreases the venous return of blood to the heart. Cardiac tamponade, surgically opening the chest, and severe aortic stenosis will effectively weaken the heart and thus decrease cardiac output. Moderate anemia will cause an arteriolar vasodilation, which increases venous return of blood back to the heart, thus increasing cardiac output.
What is normally associated with an increased cardiac output? A) Increased venous compliance B) Cardiac tamponade C) Surgically opening the chest D) Moderate anemia E) Severe aortic stenosis
E) Increased mean systemic filling pressure Several factors change during compensated heart failure to stabilize the circulatory system. Because of increased sympathetic output, the heart rate increases during compensated heart failure. The kidneys retain sodium and water, which increases blood volume and thus right atrial pressure. The increased blood volume that results causes an increase in mean systemic filling pressure, which will help to increase the cardiac output. Dyspnea usually will occur only in the early stages of compensated failure.
What is normally associated with the chronic stages of compensated heart failure? Assume the patient is resting. A) Dyspnea B) Decreased right atrial pressure C) Decreased heart rate D) Sweating E) Increased mean systemic filling pressure
Stimulates proliferation of T cells IL-2 is secreted by helper T cells when the T cells are activated by specific antigens. IL-2 plays a specific role in the growth and proliferation of helper, cytotoxic, and suppressor T cells
What is the function of IL-2 in the immune response?
Cholesterol
What is the precursor for bile salts
Acetyl CoA
What is the precursor for cholesterol
Return dietary lipids to the liver
What is the role of chylomicrons remnants?
opsonization Phagocytosis of bacteria is enhanced by the presence on their surfaces of both immunoglobulin and products of the complement cascade, which in turn bind to surface receptors on phagocytes. This "tagging" of bacteria and other particles for enhanced phagocytosis is called opsonization.
What is the term for binding of IgG and complement to an invading microbe to facilitate recognition?
Intestinal bacteria deconjugate bile salts
What must occur for bile salts to be excreted in the stool because the steroid nucleus cannot be degraded by the body
A) Changing intrapleural pressure to −1 mm Hg A shift to the right in the cardiac output curve involves an increase in the normal intrapleural pressure of −4 mm Hg. - Changing intrapleural pressure to −1 mm Hg will shift the curve to the right. - Changing mean systemic filling pressure does not change the cardiac output curve. - Taking a patient off of a ventilator, decreasing intrapleural pressure to −7 mm Hg, and breathing against a negative pressure will shift the cardiac output curve to the left.
What normally causes the cardiac output curve to shift to the left along the right atrial pressure axis? A) Changing intrapleural pressure to −1 mm Hg B) Increasing mean systemic filling pressure C) Taking a patient off a mechanical ventilator and allowing normal respiration D) Decreasing intrapleural pressure to −7 mm Hg E) Breathing against a negative pressure
B) Increased mean pulmonary filling pressure During decompensated heart failure, cardiac output decreases because of weakness of the heart and edema of the cardiac muscle. Pressures in the pulmonary capillary system increase, including the pulmonary capillary pressure and the mean pulmonary filling pressure. Depletion of norepinephrine in the endings of the cardiac sympathetic nerves is another factor that causes weakness of the heart.
What often occurs during decompensated heart failure? A) Hypertension B) Increased mean pulmonary filling pressure C) Decreased pulmonary capillary pressure D) Increased cardiac output E) Increased norepinephrine in the endings of the cardiac sympathetic nerves
High pitch = Regurgitation Low pitch = Stenosis
high pitch vs low pitch murmu
true Statins directly inhibit HMG-COA reductase which reduces endogenous cholesterol synthesis. As the cell is starved for cholesterol LDL receptors become upregulated so that more circulating cholesterol can be taken up by the cells, lower the total amount of circulating cholesterol. If you dont have functioning LDL receptors (familiar hypercholesteralemia) statins will not be effective
statin reduces circulating cholesterol levels by upregulation of LDL receptors
Decrease in helper T cells
Which of the following applies to patients with acquired immunodeficiency virus (AIDS)?
IDL
Which of the following delivers endogenous lipids to the liver and is a precursor to LDL?
LDL
Which of the following has a receptor on the plasma membrane containing clatherin for receptor-mediated endocytosis and conversion to cholesterol?
B) Increased blood volume In compensated heart failure, mean systemic filling pressure increases because of hypervolemia, and cardiac output is often at normal values. The patient has air hunger, called dyspnea, and excess sweating occurs in the early phases of compensated heart failure. However, right atrial pressure becomes elevated to very high values in these patients and is a hallmark of this disease.
Which of the following is associated with compensated heart failure? A) Increased cardiac output B) Increased blood volume C) Decreased mean systemic filling pressure D) Normal right atrial pressure
D) They are activated by the presentation of antigen by macrophage or dendritic cells Helper T cells are activated by the presentation of antigens on the surface of antigen-presenting cells. Helper T cells activate B cells to form antibodies, but B cells are not required for activation of helper T cells. Helper T cells help macrophages with phagocytosis but do not have the capability to phagocytize bacteria
Which of the following is true about helper T cells? A) They are activated by the presentation of antigen by an infected cell B) They require the presence of a competent B-cell system C) They destroy bacteria by phagocytosis D) They are activated by the presentation of antigen by macrophage or dendritic cells
D) Orthopnea In decompensated heart failure, the kidneys retain sodium and water, which causes a weight gain and an increase in blood volume. This situation increases the mean systemic filling pressure, which also stretches the heart. Therefore, a decreased mean systemic filling pressure does not occur in decompensated heart failure. The excess blood volume often overstretches the sarcomeres of the heart, which prevents them from achieving their maximal tension. An excess central fluid volume also results in orthopnea, which is the inability to breathe properly except in the upright position
Which of the following often occurs in decompensated heart failure? A) Increased renal loss of sodium and water B) Decreased mean systemic filling pressure C) Increased norepinephrine in cardiac sympathetic receptors D) Orthopnea E) Weight loss
The reduction of HMG-CoA to mevalonate
Which of the following steps in the biosynthesis of cholesterol is the key regulator? and committing step
E) 50% decrease in efferent arteriolar resistance A 50% decrease in efferent arteriolar resistance would cause a substantial decrease in GFR. - A decrease in renal arterial pressure from 100 to 80 mm Hg in a normal kidney would cause only a slight reduction in GFR in a normal kidney because of autoregulation. - All of the other changes would tend to increase GFR.
Which of the following would cause the greatest decrease in GFR in a person with otherwise normal kidneys? A) Decrease in renal arterial pressure from 100 to 80 mm Hg in a normal kidney B) 50% increase in glomerular capillary filtration coefficient C) 50% increase in proximal tubular sodium reabsorption D) 50% decrease in afferent arteriolar resistance E) 50% decrease in efferent arteriolar resistance F) 5 mm Hg decrease in Bowman's capsule pressure
ApoC-II
Which one of the following apoproteins acts as a cofactor activator of the enzyme lipoprotein lipase (LPL)?
HDL > LDL > VLDL > chylomicrons
Which one of the following sequences places the lipoproteins in the order of most dense to least dense?
A) An increase in venous resistance causes an increase in RVR An increase in venous resistance will increase resistance to venous return to a greater degree than an increase in arterial resistance. Venous return of the heart is equal to the mean systemic filling pressure minus the right atrial pressure divided by the resistance to venous return. Parasympathetic stimulation does not affect resistance to venous return, and sympathetic inhibition will reduce resistance to venous return
Which statement about resistance to venous return (RVR) is true? A) An increase in venous resistance causes an increase in RVR B) Increased parasympathetic stimulation causes an increase in RVR C) An increase in RVR causes an increase in venous return D) Sympathetic inhibition causes an increase in RVR E) Changes in arterial resistance have a greater effect on RVR than do equal changes in venous resistance
C) Pulmonary valve stenosis The mean electrical axis of the QRS of this patient is shifted rightward to 170 degrees, which indicates that the right side of the heart is involved. Both aortic stenosis and mitral regurgitation will cause a leftward shift of the QRS axis. Mitral stenosis will not affect the left ventricle, but in severe enough circumstances it could cause an increase in pulmonary artery pressure, which would cause an increase in pulmonary capillary pressure at the same time. Tricuspid stenosis will not affect the right ventricle. Therefore, pulmonary valve stenosis is the only condition that fits this set of symptoms.
118. An 80-year-old male patient at a local hospital was diagnosed with a heart murmur. A chest radiograph showed an enlarged heart but no edema fluid in the lungs. The mean QRS axis of his ECG was 170 degrees. His pulmonary wedge pressure was normal. What is the diagnosis? A) Mitral stenosis B) Aortic stenosis C) Pulmonary valve stenosis D) Tricuspid stenosis E) Mitral regurgitation
C) Aortic stenosis Aortic stenosis has a very high ventricular systolic pressure. Diastolic filling of the ventricle requires a much higher left atrial pressure. However, tricuspid stenosis and regurgitation, pulmonary valve regurgitation, and pulmonary stenosis are associated with an increase in right atrial pressure and should not affect pressure in the left atrium.
123. An increase in left atrial pressure is most likely to occur in which heart murmur? A) Tricuspid stenosis B) Pulmonary valve regurgitation C) Aortic stenosis D) Tricuspid regurgitation E) Pulmonary valve stenosis
A) Tetralogy of Fallot Right ventricular hypertrophy occurs when the right heart has to pump a higher volume of blood or pump it against a higher pressure. Tetralogy of Fallot is associated with right ventricular hypertrophy because of the increased pulmonary valvular resistance, and this also occurs during pulmonary artery stenosis. Tricuspid insufficiency causes an increased stroke volume by the right heart, which causes hypertrophy. However, tricuspid stenosis does not affect the right ventricle
126. In which condition will right ventricular hypertrophy normally occur? A) Tetralogy of Fallot B) Mild aortic stenosis C) Mild aortic insufficiency D) Mitral stenosis E) Tricuspid stenosis
Deconjugate; Dehydroxylate
Bacteria in the gut (colonic anerobes) ____ and ____ bile salts, allowing them to be reabsorbed and remain in the enterohepatic circulation
D) B cells The presence of normal skin test reactivity, which is T cell-mediated, indicates normal function of macrophages and other antigen-presenting cells, helper T cells, and cytotoxic T cells. This information, and the reduction in antibody production, localizes the defect to the B-cell lineage
A 3-year-old child who has had frequent ear infections is found to have reduced immunoglobulin levels and is unresponsive to vaccination with tetanus toxoid. However, the child has normal skin test reactivity (delayed redness and induration) to a common environmental antigen. Which cell lineage is not functioning normally? A) Macrophages B) Helper T cells C) Cytotoxic T cells D) B cells
B) Tetralogy of Fallot In tetralogy of Fallot, an interventricular septal defect and increased resistance in the pulmonary valve or pulmonary artery cause partial blood shunting toward the left side of the heart without going through the lungs. This situation results in a severely decreased arterial oxygen content. The interventricular septal defect causes equal systolic pressures in both cardiac ventricles, which causes right ventricular hypertrophy and a wall thickness very similar to that of the left ventricle.
A 50-year-old woman had an echocardiogram. The results indicated a thickened right ventricle. Other data indicated that the patient had severely decreased arterial oxygen content and equal systolic pressures in both cardiac ventricles. What condition is present? A) Interventricular septal defect B) Tetralogy of Fallot C) Pulmonary valve stenosis D) Pulmonary valve regurgitation E) Patent ductus arteriosus
D) Administering a blood volume expander Cardiogenic shock results from a weakening of the cardiac muscle many times after coronary thrombosis, which can result in a vicious circle because of low cardiac output resulting in a low diastolic pressure. This causes a decrease in coronary flow, which decreases the cardiac strength even more. Therefore, arterial pressure, particularly diastolic pressure, must be increased in patients with cardiogenic shock with either vasoconstrictors or volume expanders. In this patient the best answer is to infuse plasma. Placing tourniquets on all four limbs decreases the central blood volume, which would worsen the condition of the patient in shock.
A 60-year-old man had a heart attack 2 days ago, and his blood pressure has continued to decrease. He is now in cardiogenic shock. Which therapy would be most beneficial? A) Placing tourniquets on all four limbs B) Administering a sympathetic inhibitor C) Administering furosemide D) Administering a blood volume expander E) Increasing dietary sodium intake
A) Antigen-antibody complexes being formed in blood vessels in the skin Because the person has demonstrated allergic reactions, the initial reaction would be due to an antigenantibody reaction and the activation of the complement system. Influx of neutrophils, activation of T-helper cells, and sensitized lymphocytes would take some time.
A 9-year-old girl has nasal discharge and itching of the eyes in the spring every year. An allergist performs a skin test using a mixture of grass pollens. Within a few minutes the girl exhibits a focal redness and swelling at the test site. This response is most likely due to A) Antigen-antibody complexes being formed in blood vessels in the skin B) Activation of neutrophils due to injected antigens C) Activation of CD4 helper cells and the resultant generation of specific antibodies D) Activation of cytotoxic T lymphocytes to destroy antigens
High LDL Low triglycerides
A patient is diagnosed with familial hypercholesterolemia (FH) type IIA, which is caused by genetic defects in the gene that encodes the LDL receptor. After testing, there is an elevation in which of the following in the blood?
Trigylcerides
A patient with excess chylomicrons would have an elevation in which of the following in the blood?
E) Decrease, decrease, increase Decreased efferent arteriolar resistance would increase renal blood flow while reducing glomerular hydrostatic pressure, which, in turn, would tend to decrease the GFR.
A selective decrease in efferent arteriolar resistance would __________ glomerular hydrostatic pressure, __________ GFR, and __________ renal blood flow. A) Increase, increase, increase B) Increase, decrease, increase C) Increase, decrease, decrease D) Decrease, increase, decrease E) Decrease, decrease, increase F) Decrease, increase, increase
Inability to produce VLDL Abetalipoproteinemia is caused by a mutation in MTP -> neither chylomicrons (intestines) or VLDL (liver) are produced Tryglycerides can not be exported out of the liver -> accumulates and causes fatty liver
Abetalipoproteinemia causes fatty liver because
D) Generation of chemotactic substances Activation of the complement system results in a series of actions, including opsonization and phagocytosis by neutrophils, lysis of bacteria, agglutination of organisms, activation of basophils and mast cells, and chemotaxis. Fragment C5a of the complement system causes chemotaxis of neutrophils and macrophages.
Activation of the complement system results in which action? A) Binding of the invading microbe with IgG B) Inactivation of eosinophils C) Decreased tissue levels of complement D) Generation of chemotactic substances
B) Increased venous constriction During exercise there is very little change in cerebral blood flow, and coronary blood flow increases. Because of the increased sympathetic output, mean systemic filling pressure increases and the veins constrict. During exercise there is also a decrease in parasympathetic impulses to the heart.
At the onset of exercise, what normally occurs? A) Decreased cerebral blood flow B) Increased venous constriction C) Decreased coronary blood flow D) Decreased mean systemic filling pressure E) Increased parasympathetic impulses to the heart
Acetyl coenzyme A Fatty acids are degraded in mitochondria by the progressive release of two-carbon segments in the form of acetyl coenzyme A. This process is known as the beta-oxidation process for degradation of fatty acids
Fatty acid degradation in mitochondria produces which two-carbon substance?
E. 0.35 Filtration fraction (FF) = GFR ÷ Renal plasma flow (RPF). GFR= Kf × (PG − PB − πG) = 10 × (70 − 20 − 35) = 150 ml/min FF = 150 ml/min ÷ 428 ml/min = 0.35
Given the following measurements, calculate the filtration fraction: Glomerular capillary hydrostatic pressure (PG) = 70 mm Hg Bowman's space hydrostatic pressure (PB) = 20 mm Hg Colloid osmotic pressure in the glomerular capillaries (πG) = 35 mm Hg Glomerular capillary filtration coefficient (Kf) = 10 ml/ min/mm Hg Renal plasma flow = 428 ml/min A) 0.16 B) 0.20 C) 0.25 D) 0.30 E) 0.35 F) 0.40
Diffusion
How are cholesterols absorbed from the intestinal lumen?
6
How many major regions are seen in the structure of the LDL receptor?
LDL = Total Cholesterol - HDL - (Triglycerides/5)
How to calculate LDL cholesterol
C) Resistance to venous return is 1.4 mm Hg/L/min The formula for resistance to venous return is mean systemic filling pressure − right atrial pressure/ cardiac output. In this example the mean systemic filling pressure is 7 mm Hg and the right atrial pressure is 0 mm Hg. The cardiac output is 5 L/min. Using these values in the previous formula indicates that the resistance to venous return is 1.4 mm Hg/L/min. Note that this formula only applies to the linear portion of the venous return curve.
In the above figure, for the cardiac output and venous return curves defined by the solid red lines (with the equilibrium at A), which of the following options is true? A) Mean systemic filling pressure is 12 mm Hg B) Right atrial pressure is 2 mm Hg C) Resistance to venous return is 1.4 mm Hg/L/min D) Pulmonary arterial flow is approximately 7 L/min E) Resistance to venous return is 0.71 mm Hg/L/min
A: Anemia Anemia will decrease resistance to venous return because of arteriolar dilation. The following mechanisms increase resistance to venous return: increased venous resistance, increased arteriolar resistance, increased sympathetic output, and obstruction of veins.
In which condition would you expect a decreased resistance to venous return? A) Anemia B) Increased venous resistance C) Increased arteriolar resistance D) Increased sympathetic output E) Obstruction of veins
E) Acute myocardial infarction Cardiac output increases in several conditions because of increased venous return. Cardiac output increases in hyperthyroidism because of the increased oxygen use by the peripheral tissues, resulting in arteriolar vasodilation and thus increased venous return. Beriberi causes increased cardiac output because a lack of the vitamin thiamine results in peripheral vasodilation. A-V fistulae also cause a decreased resistance to venous return, thus increasing cardiac output. Anemia, because of the decreased oxygen delivery to the tissues, causes an increase in venous return to the heart and thus an increase in cardiac output. Cardiac output decreases in patients with myocardial infarction.
In which condition would you normally expect to find a decreased cardiac output? A) Hyperthyroidism B) Beriberi C) A-V fistula D) Anemia E) Acute myocardial infarction
A) Dilation of the afferent arterioles Dilation of the afferent arterioles leads to an increase in the glomerular hydrostatic pressure and therefore an increase in GFR, as well as an increase in renal blood flow. Increased glomerular capillary filtration coefficient would also raise the GFR but would not be expected to alter renal blood flow. Increased plasma colloid osmotic pressure or dilation of the efferent arterioles would both tend to reduce the GFR. Increased blood viscosity would tend to reduce renal blood flow and GFR.
Increases in both renal blood flow and GFR are caused by which mechanism? A) Dilation of the afferent arterioles B) Increased glomerular capillary filtration coefficient C) Increased plasma colloid osmotic pressure D) Dilation of the efferent arterioles
D) Both antibody production and T cell-mediated cytotoxicity Patients with HIV have specific loss of T-helper cells, resulting in a loss of T-cell help for both antibody production and activation/proliferation of cytotoxic T cells. Assuming that mast cells can be appropriately stimulated (i.e., bear sufficient residual surface-bound IgE and are exposed to relevant antigen), their processes for degranulation are intact.
Patients with human immunodeficiency virus (HIV) exhibit abnormal functioning of which of the following mechanisms? A) Antibody production only B) T cell-mediated cytotoxicity only C) Degranulation of appropriately stimulated mast cells D) Both antibody production and T cell-mediated cytotoxicity
true Cholesterol is hydrophobic Cholesterol can turn into steroid hormones Cholesterol can appear in esterfied form in the core of lipoproteins
Precursors of cholesterol can be converted to vitamin D
B) Activation of cytotoxic T cells Presentation of an antigen on an infected cell will result in activation of the cytotoxic T cells to kill the infected cell. Presentation of an antigen by macrophages will activate helper T cells, which can promote antibody production and support proliferation of both helper and cytotoxic T cells.
Presentation of antigen on major histocompatibility complex (MHC)-I by a cell will result in which of the following? A) Generation of antibodies B) Activation of cytotoxic T cells C) Increase in phagocytosis D) Release of histamine by mast cells
D) Glycerol and fatty acids Triglycerides are hydrolyzed to glycerol and fatty acids, which, in turn, are oxidized to provide energy. Almost all cells, with the exception of some brain tissue, can use fatty acids almost interchangeably with glucose for energy
The first stage in using triglycerides for energy is hydrolysis of the triglycerides to which substances? A) Acetyl coenzyme A and glycerol B) Cholesterol and fatty acids C) Glycerol 3-phosphate and cholesterol D) Glycerol and fatty acids E) Phospholipids and glycerol
In-rushing of blood into the ventricles from atrial contraction
The fourth heart sound is associated with which mechanism?
D) Orthopnea In persons with decompensated heart failure, the kidneys retain sodium and water, which causes a weight gain and an increase in blood volume. This effect increases the mean systemic filling pressure, which also stretches the heart. Therefore, a decreased mean systemic filling pressure does not occur in decompensated heart failure. The excess blood volume often will overstretch the sarcomeres of the heart, which will prevent them from achieving their maximal tension. An excess central fluid volume also results in orthopnea, which is the inability to breathe properly except in the upright position.
What often occurs in decompensated heart failure? A) Increased renal loss of sodium and water B) Decreased mean systemic filling pressure C) Increased norepinephrine in cardiac sympathetic nerves D) Orthopnea E) Weight loss
UV light
What produces cholecalciferol in the skin, hydroxylating 7-dehydrocholesterol to form active vitamin D?
E. Increasing sympathetic stimulation of the heart The plateau level of the cardiac output curve, which is one measure of cardiac contractility, decreases in several circumstances. Some of these circumstances include severe cardiac tamponade, which increases the pressure in the pericardial space, and increasing parasympathetic stimulation of the heart. Increased sympathetic stimulation of the heart increases the level of the cardiac output curve by increasing heart rate and contractility.
What will elevate the plateau of the cardiac output curve? A) Surgically opening the thoracic cage B) Connecting a patient to a mechanical ventilator C) Cardiac tamponade D) Increasing parasympathetic stimulation of the heart E) Increasing sympathetic stimulation of the heart
D) Activation of helper T cells Presentation of an antigen on the surface of macrophages or dendritic cells results in the activation of helper T cells. Activation of helper T cells then initiates the release of lymphokines that stimulate proliferation and activation of helper and cytotoxic T cells and B cells and the generation of antibodies
What will occur after presentation of antigen by a macrophage? A) Direct generation of antibodies B) Activation of cytotoxic T cells C) Increase in phagocytosis D) Activation of helper T cells
C) Decreased parasympathetic stimulation of the heart The plateau level of the cardiac output curve, which is one measure of cardiac contractility, decreases in several circumstances. Some of these include myocarditis, severe cardiac tamponade that increases the pressure in the pericardial space, myocardial infarction, and various valvular diseases such as mitral stenosis. Decreased parasympathetic stimulation of the heart actually moderately increases the level of the cardiac output curve by increasing the heart rate.
What will usually increase the plateau level of the cardiac output curve? A) Myocarditis B) Severe cardiac tamponade C) Decreased parasympathetic stimulation of the heart D) Myocardial infarction E) Mitral stenosis
C) 50% decrease in efferent arteriolar resistance A 50% reduction in efferent arteriolar resistance would cause a large decrease in GFR—greater than 10%. A decrease in renal artery pressure from 100 to 85 mm Hg would cause only a slight decrease in GFR in a normal, autoregulating kidney. A decrease in afferent arteriole resistance, a decrease in plasma colloid osmotic pressure, or an increase in the glomerular capillary filtration coefficient would all tend to increase GFR.
What would tend to decrease GFR by more than 10% in a normal kidney? A) Decrease in renal arterial pressure from 100 to 85 mm Hg B) 50% decrease in afferent arteriolar resistance C) 50% decrease in efferent arteriolar resistance D) 50% increase in the glomerular capillary filtration coefficient E) Decrease in plasma colloid osmotic pressure from 28 to 20 mm Hg
Subintimal space
Where do foam cells form during atherosclerosis to deform the vessel inward (lumen) and increase the likelihood of a clot?
C) Increased glomerular capillary filtration coefficient The glomerular capillary filtration coefficient is the product of the hydraulic conductivity and surface area of the glomerular capillaries. Therefore, increasing the glomerular capillary filtration coefficient tends to increase GFR. - Increased afferent arteriolar resistance, decreased efferent arteriolar resistance, increased Bowman's capsule hydrostatic pressure, and decreased glomerular hydrostatic pressure tend to decrease GFR
Which change tends to increase GFR? A) Increased afferent arteriolar resistance B) Decreased efferent arteriolar resistance C) Increased glomerular capillary filtration coefficient D) Increased Bowman's capsule hydrostatic pressure E) Decreased glomerular capillary hydrostatic pressure
C) Increased renal blood flow, increased GFR, and increased peritubular capillary hydrostatic pressure A 50% reduction in afferent arteriolar resistance with no change in arterial pressure would increase renal blood flow and glomerular hydrostatic pressure, thereby increasing GFR. At the same time, the reduction in afferent arteriolar resistance would raise peritubular capillary hydrostatic pressure.
Which changes would you expect to find after administering a vasodilator drug that caused a 50% decrease in afferent arteriolar resistance and no change in arterial pressure? A) Decreased renal blood flow, decreased GFR, and decreased peritubular capillary hydrostatic pressure B) Decreased renal blood flow, decreased GFR, and increased peritubular capillary hydrostatic pressure C) Increased renal blood flow, increased GFR, and increased peritubular capillary hydrostatic pressure D) Increased renal blood flow, increased GFR, and no change in peritubular capillary hydrostatic pressure E) Increased renal blood flow, increased GFR, and decreased peritubular capillary hydrostatic pressure
B) Congestive heart failure Mean systemic pressure is increased by factors that increase blood volume or decrease vascular capacity. Sympathetic inhibition and venous dilation both decrease the mean systemic filling pressure. In congestive heart failure, the kidneys retain great quantities of sodium and water, resulting in an increase in blood volume, which causes large increases in mean systemic filling pressure.
Which condition is normally associated with an increase in mean systemic filling pressure? A) Decreased blood volume B) Congestive heart failure C) Sympathetic inhibition D) Venous dilation
A) Increased right atrial pressure During compensated heart failure, release of angiotensin II and aldosterone is increased, causing the kidneys retain sodium and water, which increases the blood volume in the body and the venous return of blood to the heart. This situation results in an increase in right atrial pressure. Increased sympathetic output during compensated heart failure will increase heart rate. Air hunger, called dyspnea, occurs during any type of exertion. The patient also has orthopnea, which is the air hunger that occurs from being in a recumbent position
Which condition normally occurs during the early stages of compensated heart failure? A) Increased right atrial pressure B) Normal heart rate C) Decreased angiotensin II release D) Decreased aldosterone release E) Increased urinary output of sodium and water
D) Increased venous compliance Mean systemic filling pressure is a measure of the tightness of fit of the blood in the circulation. Mean systemic filling pressure is increased by factors that increase blood volume and decrease the vascular compliance. Therefore, an decreased venous compliance, not an increased compliance, would cause an increase in mean systemic filling pressure. Norepinephrine administration and sympathetic stimulation cause arteriolar vasoconstriction and decreased vascular compliance, resulting in an increase in mean systemic filling pressure. Increased blood volume and skeletal muscle contraction, which cause a contraction of the vasculature, also increase this filling pressure.
Which condition would be expected to decrease mean systemic filling pressure? A) Norepinephrine administration B) Increased blood volume C) Increased sympathetic stimulation D) Increased venous compliance E) Skeletal muscle contraction
Inrushing of blood into the ventricles in the early to middle part of diastole
Which mechanism is associated with the third heart sound
C) They are activated by the presentation of antigen by an infected cell Cytotoxic cells act on infected cells when the cells have the appropriate antigen located on the surface. The cytotoxic T cells are stimulated by lymphokines generated by activation of helper T cells. Cytotoxic T cells destroy an infected cell by releasing proteins that punch large holes in the membrane of the infected cells. There is no interaction between cytotoxic T cells and B cells
Which of the following applies to cytotoxic T cells? A) They require the presence of a competent B-lymphocyte system B) They require the presence of a competent suppressor T-lymphocyte system C) They are activated by the presentation of antigen by an infected cell D) They destroy bacteria by initiating macrophage phagocytosis
