Chapter 19 and 18 Quiz
Blood flow would be increased by __________.
increasing cardiac output
...The major long-term mechanism of blood pressure control is provided by the __________.
kidneys The kidneys act both directly and indirectly to regulate arterial pressure and provide the major long-term mechanism of blood pressure control by altering blood volume.
!!!Blood flows from the lungs to the __________ via the __________.
left atrium; pulmonary veins See page 722. Freshly oxygenated blood flows from the lungs to the left atrium via the pulmonary veins.
The role of the atrioventricular node (AV node) is to __________.
slow down impulses so that the atria can contract to fill the adjacent ventricles with blood See page 675. The impulses of the heart originate at the SA node. The impulse is then transmitted to the AV node, where the impulse slows down to allow the atria to completely contract, thereby filling the adjacent ventricles. The AV node then transmits the impulse to the bundle of His, which branches into left and right bundle branches. The bundle branches give rise to the Purkinje fibers, which transmit the impulse to the ventricle walls and stimulate ventricular contraction.
anterior interventricular artery
supplies blood to the interventricular septum and anterior walls of both ventricles
Cardiac output
the amount of blood pumped by each ventricle in one minute
pulse pressure
the difference between systolic and diastolic pressure
The absolute refractory period refers to the time during which __________.
the muscle cell is not in a position to respond to a stimulus of any strength During the absolute refractory period, a muscle cell will not respond to a stimulus of any strength.
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tricuspid valve B. valve between the right atrium and right ventricle
...Which of the following is the correct sequence of layers in the vessel wall from outside to inside?
tunica externa, tunica media, tunica intima The tunica externa is the outermost layer, the tunica media is in the middle layer, and the tunica intima lines the vessel.
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Fluids would be likely to leave or filter out of the capillary if __________. Your Answer: net hydrostatic pressure (HP) is greater than net osmotic pressure (OP)
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The difference between systolic and diastolic pressure is the pulse pressure. The mean arterial pressure (MAP) is the pressure that propels blood through the tissues.
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The endocardium is composed of __________. Your Answer: simple squamous epithelium The endocardium is a thin sheet of simple squamous epithelium (endothelium).
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The flow of blood from the left ventricle to the right atrium is called the __________. Your Answer: systemic circulation The flow of blood from the left ventricle to the right atrium is called the systemic circulation.
Systemic circulation
The flow of blood from the left ventricle to the right atrium is called the systemic circulation.
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The inferior vena cava brings blood from the lower regions of the body and empties into the __________. Your Answer: right atrium The right atrium receives blood both from the superior and inferior vena cavae.
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The interventricular septum forms a dividing wall between the __________. Your Answer: left and right ventricles The interventricular septum separates the two ventricles.
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The normal pacemaker of the heart is the __________. Your Answer: SA node The SA node generates impulses faster than the other node and sets the pace for the heart.
Stroke volume
The volume of blood pumped by one ventricle with each heartbeat 14.5
Blood enters the myocardium of the heart by coronary vessels that originate from the __________.
aorta The coronary artery branches from the aorta near the base.
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aortic semilunar valve A. prevents backflow of blood into the left ventricle
Baroreceptors
are effective in short-term regulation of blood pressure.
Blood flows directly from __________ into capillary beds. Your Answer:
arterioles
...The only vessels that provide direct access to nearly every cell in the body are the __________.
capillaries If blood vessels are compared to a system of expressways and roads, the capillaries are the back alleys and the driveways that provide direct access to nearly every cell in the body.
...Exchange of gases and nutrients occurs by diffusion between the __________.
capillaries and tissue cells Oxygen, carbon dioxide, most nutrients, and metabolic wastes pass between the blood and interstitial fluid by diffusion through the capillaries.
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cardiac cycle E. the events associated with blood flow through the heart during one complete heartbeat 14.2
...Which of the following arteries branches to form the common hepatic artery, left gastric artery, and splenic artery?
celiac trunk The celiac trunk branches to supply much of the upper abdomen.
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2. Correct The lining of the heart chambers is called the __________. Your Answer: endocardium
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3. Correct The superior chambers of the heart are called the __________. Your Answer: atria
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4. Correct Freshly oxygenated blood is delivered to the __________ and then it passes into the __________ to be pumped to the entire body. Your Answer: left atrium; left ventricle
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A metarteriole is a vessel that __________. Your Answer: is intermediate between the arteriole and the capillary bed A metarteriole is a vessel that is intermediate between the arteriole and the capillary bed.
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A positive net filtration pressure (NFP) would force fluid out of the blood. A negative NFP would result in reabsorption.
angiotensin II
A. hormonal control of blood flow
circumflex artery
A. supplies blood to the left atrium and posterior walls of the left ventricle
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All of the following are examples of venous sinuses EXCEPT __________. Your Answer: venous sinuses Correct Answer: carotid sinuses Venous sinuses are specialized flattened veins.
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An elastic lamina on both sides of the tunica media is a characteristic of __________. Your Answer: all arteries Correct Answer: muscular arteries Only muscular arteries have an elastic lamina on both sides of the tunica media.
Which of the following is true when comparing arteries and veins?
Arteries carry blood away from the heart; veins carry blood to the heart.
sympathetic impulses
C. nervous system control of blood flow
right marginal artery
C. supplies blood to the lateral right side of the myocardium
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Correct diastole B. relaxation 14.4
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Correct systole A. contraction 14.3
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Diastolic pressure is the lowest aortic pressure, approximately 70-80 mm Hg in healthy adults.
The hepatic portal system collects blood from the __________ and then routes it to the __________.
GI tract; liver See page 742. Substances that are absorbed into the capillaries surrounding the GI tract will be transported to the liver via the hepatic portal system.
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Hypertension is defined physiologically as a condition of sustained arterial pressure of __________ or higher. Your Answer: 140/90
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Into which chamber of the heart do the pulmonary veins deliver blood? Your Answer: left ventricle Correct Answer: left atrium See page 668. The pulmonary veins deliver blood to the left atrium.
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Most neural controls of blood pressure involve input from baroreceptors, which are sensitive to __________. Your Answer: to changes in blood pressure Baroreceptors are sensitive to changes in blood pressure.
Choose the correct sequence of current flow through the heart wall.
SA node, AV node, AV bundle, right and left bundle branches, Purkinje fibers Impulses generated by the SA node spread to the AV node, then to the AV bundle, then to the bundle branches, and finally to the Purkinje fibers.
Blood from the brain is returned to the heart via the __________.
Superior vena cava
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Systolic pressure is the peak pressure achieved as the heart ejects blood into the aorta, averaging about 120 mm Hg in healthy adults.
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The P wave of an electrocardiogram represents __________. Your Answer: atrial depolarization
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Up to 65% of the body's blood supply is found in __________. Your Answer: arteries Correct Answer: veins Up to 65% of the body's blood supply is found in veins.
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When the mitral valve closes, it prevents the backflow of blood from the __________. Your Answer: left ventricle into the left atrium The mitral valve closes to prevent the backflow of blood from the left ventricle into the left atrium.
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Which is correctly paired? Your Answer: arrhythmia: AV node failure Correct Answer: ectopic focus: an abnormal pacemaker See page 676. Extrasystole, or premature contraction, can be caused by ectopic or abnormal pacemakers (also called ectopic foci). An ectopic focus can result when the SA node is defective. Additionally, some substances (such as caffeine and nicotine) consumed in excess can generate an ectopic focus. Any defect in the intrinsic conduction system of the heart can generate an irregular heart rhythm (an arrhythmia). Damage to the AV node can lead to a heart block. In a complete heart block, impulses do not reach the ventricles; as a result, the ventricles beat at their intrinsic rate, which is too slow to maintain adequate circulation. Fibrillation is characterized by rapid and irregular or out-of-phase contractions of the heart chambers.
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Which is the correct sequence of layers in the heart wall, starting with the outer layer? Your Answer: epicardium, myocardium, endocardium The superficial epicardium, the middle myocardium, and the inner endocardium form the heart wall.
antidiuretic hormone
Which of the following acts on the kidneys and blood vessels to raise blood pressure?
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Which of the following blood vessels is the most susceptible to atherosclerosis? Your Answer: the cerebral arteries Correct Answer: the aorta Although all arteries are susceptible to atherosclerosis, the aorta is the most susceptible.
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Which of the following conditions would NOT increase the chances of developing varicose veins? Your Answer: running in place Running in place would not increase the chances of developing varicose veins.
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Which of the following is NOT a role of the pericardium? Your Answer: It facilitates heart contraction.
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Which of the following is a difference between cardiac muscle and skeletal muscle? Your Answer: Unlike skeletal muscle, cardiac muscle does not use a sliding filament mechanism for contraction. Correct Answer: Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic. See page 671. Cardiac muscle is striated and utilizes the sliding-filament mechanism for contraction, like skeletal muscle. Both cardiac and skeletal muscle depend upon calcium ion influx to lead to depolarization. Unlike skeletal muscle, cardiac muscle cells have a greater concentration of mitochondria, giving cardiac cells a high resistance to fatigue. Cardiac muscle cells are highly dependent upon oxygen in order to carry out aerobic respiration. Cardiac muscle cells die faster than skeletal muscle cells if deprived of oxygen. Additionally, the plasma membranes of cardiac muscle cells interlock, while skeletal muscle cell fibers are independent. Cardiac cells can be autorhythmic, a property not seen in skeletal muscle fibers.
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Which of the following is the major force generating blood flow? Your Answer: blood viscosity Correct Answer: pumping action of the heart The pumping action of the heart generates blood flow.
The coronary arteries arise from the __________.
Your Answer: aorta The two coronary arteries that supply the heart arise from the base of the aorta.
The tricuspid valve is located between the __________.
Your Answer: right atrium and right ventricle The tricuspid valve is located between the right atrium and the right ventricle.
The cardiac cycle includes all of the following events EXCEPT __________.
Your Answer: the number of times the heart beats in one minute The cardiac cycle refers to the mechanical events occurring during one heartbeat.
...Lipoprotein (a)
__________ inhibits fibrinolysis by competing with plasminogen and may contribute to the formation of atherosclerotic plaques. Although cholesterol may contribute to the formation of atherosclerotic plaques, it does not compete with plasminogen. Lipoprotein (a) competes with plasminogen but cannot dissolve clots, and it participates in the formation of atherosclerotic plaques.
...Any condition in which blood vessels are inadequately filled and blood cannot circulate normally is called __________.
circulatory shock Circulatory shock results in inadequate blood flow to meet tissue needs when blood vessels are inadequately filled and blood cannot circulate normally.
The second heart sound (the 'dup' of 'lub-dup') is caused by the __________.
closure of the semilunar valves See pages 678-9. The first heart sound (the 'lub' of 'lub-dup') is generated by the closure of the atrioventricular valves. The second heart sound (the 'dup' sound) is caused by closure of the semilunar valves.
The vessels that exhibit the lowest level of permeability are the __________.
continuous capillaries
...The minute-to-minute blood flow through the capillary beds is determined by the __________.
diameter of arterioles Elastic arteries are relatively inactive in vasoconstriction, and this does not determine the amount of blood flow through the capillary beds.
...Which of the following types of blood vessels have the proportionally thickest tunica media of all vessels?
distributing arteries Distributing arteries have the thickest tunica media of all vessels.
...arterioles
do not contain intercellular clefts.
...Which of the following veins is the longest in the body?
great saphenous vein The great saphenous vein is the longest in the body, running from the sole of the foot up to the inguinal region (without changing names).
The most muscular chamber of the heart is the __________.
left ventricle The left side of the heart is the systemic circuit pump. Since the left ventricle pumps blood to the entire body, it makes sense that it is a more powerful pump than the right ventricle, which only needs to pump blood to the nearby lungs. The powerful pumping ability of the left ventricle is due in part to its thick musculature; the walls of the left ventricle are about three times thicker than the walls of the right ventricle. Since the demands on the left ventricle are so great, it receives the highest percentage of the coronary blood supply.
During systemic circulation, blood leaves the __________.
left ventricle and goes directly to the aorta The movement of oxygenated blood from the left ventricle to the aorta constitutes part of the systemic circuit.
During systemic circulation, blood leaves the __________.
left ventricle and goes directly to the aorta The movement of oxygenated blood from the left ventricle to the aorta is part of the systemic circuit.
diastolic pressure
lowest level of aortic pressure
nitric oxide
metabolic control of blood flow
...Which of the layers of an artery wall is regulated by the sympathetic nervous system and many hormones?
middle layer The sympathetic nervous system and many hormones do not regulate the outer layer of an artery.
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mitral valve D. valve between the left atrium and left ventricle
In the fetus, blood from the left and right sides of the heart normally
mix
Cardiogenic shock is most likely to result from __________.
multiple heart attacks See page 717. Vascular shock occurs when blood volume is normal but vasomotor tone is suddenly lost, causing extreme vasodilation. The massive vasodilation event leads to a drastic and dangerous drop in blood pressure. Vascular shock can be triggered by anaphylaxis, septic shock, and by certain bacterial toxins. Hypovolemic shock is a result of large-scale blood loss; it is the most common form of circulatory shock. Cardiogenic shock is a result of heart failure or damage; it can result from multiple myocardial infarcts (heart attacks).
stretch of vascular smooth muscle
myogenic control of blood flow
Which of the following would lead to a decrease in heart rate?
parasympathetic stimulation See page 684. Sympathetic stimulation (for example, exercise) can lead to the release of epinephrine and norepinephrine, which increase heart rate. A sharp decrease in blood volume also leads to an increase in heart rate. Low metabolic rate, cold temperatures, and parasympathetic stimulation decrease heart rate.
The inner lining of the fibrous pericardium is formed by the __________.
parietal layer of serous pericardium The pericardial sac is lined by a serous membrane called the parietal pericardium.
systolic pressure
peak of aortic pressure
...The presence of __________ stabilizes the wall of capillaries.
pericytes Capillaries do not contain elastic fibers. The presence of pericytes stabilizes the walls of capillaries.
...Which of the following regulates blood flow at the entrance to each true capillary?
precapillary sphincter The cuff of smooth muscle fibers surrounding the root of each true capillary at the metarteriole that acts as a valve to regulate blood flow into the capillary is a precapillary sphincter.
mean arterial pressure
pressure that propels blood to the tissues
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pulmonary semilunar valve C. prevents backflow of blood into the right ventricle See pages 662-7. The tricuspid valve is located between the right atrium and right ventricle. The mitral valve (also called the bicuspid valve) is located between the left atrium and left ventricle. The semilunar valves are structurally designed to prevent backflow of blood into the adjacent ventricle. The pulmonary semilunar valve is the gatekeeper to the pulmonary circuit and is found between the pulmonary trunk and the right ventricle. The aortic semilunar valve is found between the left ventricle and aorta, and is the gatekeeper to the systemic circuit.
The inferior vena cava brings blood from the lower regions of the body and empties into the __________.
right atrium The right atrium receives blood both from the superior and inferior vena cavae.
Identify the correct sequence of blood flow through the chambers of the heart.
right atrium, right ventricle, lungs, left atrium, left ventricle right atrium, right ventricle, lungs, left atrium, left ventricle
During pulmonary circulation blood leaves the __________.
right ventricle and moves to the lungs The movement of deoxygenated blood from the right ventricle to the lungs is part of the pulmonary circuit.
During pulmonary circulation, blood leaves the __________.
right ventricle and moves to the lungs The movement of oxygen-poor blood from the right ventricle to the lungs is part of the pulmonary circuit.
posterior interventricular artery
runs to the apex of the heart
Correct The endothelium is composed of __________.
simple squamous epithelium The endothelium is the thin sheet of simple squamous epithelium lining the vessel.
Which of the following would experience increased blood flow during exercise?
skin See pages 714-5. The brain has a relatively constant flow of blood during rest and during exercise. The muscles and the skin experience increased blood flow during exercise. The kidneys and the GI tract (i.e., the stomach and intestines) would have decreased blood flow during exercise.
The vessel layer that has a direct role in vasoconstriction is the __________.
tunica media See page 693. Blood vessels are composed of three layers (tunics). The innermost layer is the tunica intima, the middle layer is the tunica media, and the outermost layer is the tunica externa. The tunica media contains the muscular portion of the vessel and is directly involved in vasoconstriction and vasodilation.
...Loss of vasomotor tone that results in a huge drop in peripheral resistance is known as __________.
vascular shock In vascular shock, blood volume is normal and constant but there is an abnormal expansion of the vascular beds, resulting in a huge drop in peripheral resistance, causing blood pressure to fall rapidly.
...Reduction in the lumen diameter of a blood vessel as the smooth muscle contracts is known as __________.
vasoconstriction Depending on the bodies needs, either vasoconstriction (reduction in lumen diameter as the smooth muscle contracts) or vasodilation (increase in diameter) occurs.
The vasa vasorum are
very small vessels that feed the myocardium.
When would the capillary beds surrounding the gastrointestinal organs be open?
when digesting a meal
