Topic 6 - Cardiovascular

When does aortic diastolic pressure occur? Aortic diastolic pressure occurs during: ventricular diastole only ventricular systole only both ventricular diastole and systole neither ventricular diastole and systole

ventricular systole only

The percentage of total blood volume occupied by erythrocytes is called the _______ that for women has a normal range of _______. buffy coat; 1% hematocrit; 38-46% plasma; 55% hematocrit; 40-54% hematocrit; 55%

hematocrit; 38-46%

Which of the following events occur during systole? pressure in the atria exceeds pressure in the ventricles and the atrioventricular valves open pressure in the ventricles eventually exceeds pressure in the arteries and the semilunar valves open. the atria contract and pump blood into the ventricles no blood enters the arteries

pressure in the ventricles eventually exceeds pressure in the arteries and the semilunar valves open.

During systemic circulation, blood leaves the: right ventricle and moves to the lungs. lungs and moves to the left atrium. left ventricle and goes directly to the aorta. right ventricle and goes directly to the aorta. right atrium and goes directly to the lungs.

left ventricle and goes directly to the aorta.

An individual with a blood pressure of ______ may have hypertension. 140/90 115/75 110/70 90/60 85/55

140/90

If the SA node is damaged, which part of the heart is most likely to take over as a pacemaker? atrial myocardial cells AV nodal cells Purkinje fibers ventricular myocardial cells

AV nodal cells

Which of the following are functions of blood in the body? Transportation of gases, nutrients, hormones, and wastes. Regulation of pH, temperature, and movement of fluid across capillary walls. Protection including clotting and providing immune cells and proteins. All of these are functions of blood.

All of these are functions of blood.

The atrioventricular (AV) node is important because it: delays the transmission of the electrical impulses to the ventricles in order for the atria to finish contracting. directs electrical impulses from the atria to the ventricles. serves as the pacemaker in a healthy heart. Both A and B are correct. A, B, and C are correct.

Both A and B are correct.

Why has a homeostatic mechanism for regulation of blood pressure evolved that is so easily reset?

If you need to stand up or sit down, blood pressure needs to change quickly with it.

Given CO is cardiac output, SV is stroke volume, HR is heart rate, and TPR is total peripheral resistance, which of the following equations correctly calculates the mean arterial pressure (MAP)? MAP = SV x HR x TPR MAP = (SV x HR)/TPR MAP = CO x SV x HR x TPR MAP = (SV x HR)/CO MAP = CO x SV

MAP = SV x HR x TPR

In an ECG taken from a person who has no SA node activity, which component will not appear? P wave QRS complex ST segment T wave

P wave

What event in the heart is associated with the first heart sound? Ventricular relaxation. Closing of the semilunar valves. The onset of ventricular systole. The onset of ventricular diasystole. The falling of left ventricular pressure below aortic pressure.

The onset of ventricular systole.

Which of the following events result in the second heart sound? The AV valves open. The AV valves close. The semilunar valves open. The semilunar valves close. The atria contract.

The semilunar valves close.

What does the electrocardiogram (ECG) QRS wave indicate is happening in the heart? The atria are depolarizing. The ventricles are depolarizing while the atria repolarize. The ventricles are repolarizing. The heart is at rest.

The ventricles are depolarizing while the atria repolarize.

Which of the following events does not occur when the semilunar valves are open? Ventricular relaxation. Blood enters pulmonary arteries and the aorta. AV valves are closed. Ventricular contraction. All of the above occur when the semilunar valves are open.

Ventricular relaxation.

The action of acetylcholine after binding to muscarinic acetylcholine receptors (M-AChR) on the SA node is to: a. open K+ channels, causing hyperpolarization and a decreased rate of spontaneous depolarization. b. close K+ channels, causing depolarization and an increased rate of spontaneous depolarization. c. open Ca2+ channels, causing increased Ca2+ entry and a stronger contraction. d. close Ca2+ channels, causing decreased Ca2+ entry and a faster rate of spontaneous depolarization.

a. open K+ channels, causing hyperpolarization and a decreased rate of spontaneous depolarization.

During the isovolumetric ventricular relaxation phase of the cardiac cycle: the atria contract and pump blood into the ventricles the ventricles contract and pump blood into the blood vessels both atria and ventricles are relaxed the ventricles contract but ventricular pressure is lower than arterial pressure

both atria and ventricles are relaxed

How does the impulse to contract slow down slightly before it is transferred into the ventricles? a. It makes a detour and travels to the brain and back. b. There is a parasympathetic brake on the AV node. c. Junctional fibers leading into the AV node have very small diameters. d. The skeleton of the heart prevents the impulse from being transmitted rapidly.

c. Junctional fibers leading into the AV node have very small diameters.

When do the AV valves close during the cardiac cycle? a. when pressure inside the ventricles is at its lowest. b. when pressure inside the atria is greater than that inside the ventricles. c. when ventricular pressure exceeds that of the atria d. when pressure is greater in the aorta than in the left ventricle

c. when ventricular pressure exceeds that of the atria

The tricuspid valve is closed ________. during ventricular relaxation during ventricular contraction when the bicuspid valve is open while the atrium is contracting by the movement of blood from atrium to ventricle

during ventricular contraction

The amount of blood in the ventricles just before they contract is called the: end diastolic volume end systolic volume stroke volume cardiac output

end diastolic volume

The Frank-Starling law of the heart says that the higher the end diastolic volume, the: lower the cardiac output higher the end systolic volume lower the blood pressure higher the stroke volume

higher the stroke volume

Which of the following would be an effect of cutting the vagus nerve? reduced heart rate increased heart rate reduced strength of contraction increased secretion of acetylcholine

increased heart rate

Moving from a prone (lying down) to an erect position decreases blood pressure and blood flow in the head and upper part of the body. This results in _______ stretch of the baroreceptors and the sensory (afferent) neurons associated with the baroreceptors send action potentials _______ to the cardiovascular center. greater; at a faster rate less; with lower amplitudes greater; with greater amplitudes less; at a slower rate

less; at a slower rate

The importance of the plateau phase of the action potential of myocardial cells is in: preventing tetanus (a prolonged contraction) of the myocardial cells. preventing overstretching of the myocardial cells. enhancing the efficiency of oxygen use by the myocardical cells. preventing fibrillation (an irregular and often rapid heart rate).

preventing tetanus (a prolonged contraction) of the myocardial cells.

The superior vena cava, inferior vena cava, and coronary sinus all drain into the: right atrium left atrium right ventricle left ventricle none of these

right atrium

During pulmonary circulation, blood leaves the: right atrium and goes directly to the left ventricle. left ventricle and moves to the lungs. right atrium and goes directly to the lungs. right ventricle and moves to the lungs. right ventricle and goes directly to the aorta.

right ventricle and moves to the lungs.

The cardiac pacemaker potential is caused by cyclic changes in membrane potential that occur in which of the following sequences? slow inflow of Na+ ; rapid K+ inflow; slow K+ outflow slow inflow of Ca2+ ; rapid Na+ inflow; rapid K+ outflow slow inflow of K+ without Na+ outflow; rapid Na+ inflow; rapid K+ outflow slow inflow of Na+ without K+ outflow; rapid Ca2+ inflow; rapid K+ outflow

slow inflow of Na+ without K+ outflow; rapid Ca2+ inflow; rapid K+ outflow

Where is the highest amount of carbon dioxide found? in the air in the alveoli the arteries entering the lung the veins leaving the lung

the arteries entering the lung

Poiseuille's Law explains the effect of three factors on resistance to blood flow. According to this law, the smaller the radius of a vessel, the higher the resistance to blood flow. increased resistance causes increased blood flow. the higher the blood viscosity, the lower the resistance to blood flow. a longer blood vessel offers less resistance than a shorter vessel of the same radius.

the smaller the radius of a vessel, the higher the resistance to blood flow.