Question 1

The period between the filling of the ventricles and the opening of the semilunar valves is called:

Accepted Answer

Isovolumetric ventricular contraction is the phase in the cardiac cycle where the ventricles contract with no change in volume because all valves are closed, occurring right before the semilunar valves open to allow ejection of blood into the arteries.

Question 2

Which of the following is not a means by which venous blood is returned to the heart?

Accepted Answer

The answer of Which of the following is not a...

Question 3

The chemoreceptors in the carotid bodies are particularly sensitive to:

Accepted Answer

The answer of The chemoreceptors in the carotid bodies are...

Question 4

Which of the following is true of the conduction system of the heart?

Accepted Answer

The answer of Which of the following is true of...

Question 5

Atrial systole causes blood to:

Accepted Answer

Atrial systole causes the atria to contract, which increases the pressure in the atria, forcing blood through the open cuspid valves and into the ventricles. The semilunar valves are closed during this time, preventing blood from entering the pulmonary artery and aorta. Therefore, option D is incorrect as blood does not leave the heart during atrial systole.

Question 6

Blood in the veins of which organ is not considered part of the "blood reservoir" system?

Accepted Answer

The answer of Blood in the veins of which organ...

Question 7

Circulatory shock caused by an acute allergic reaction is called _____ shock.

Accepted Answer

Anaphylactic shock is caused by an acute allergic reaction and is a type of circulatory shock. Cardiogenic shock is caused by heart failure, hypovolemic shock is caused by a decrease in blood volume, and septic shock is caused by a severe infection.

Question 8

Match each part of the conduction system of the heart to the description of its location or function.
-branches that are at the terminal ends of the bundles of His

Accepted Answer

Purkinje fibers are found at the terminal ends of the bundles of His.

Answer: E
 Bundles of His branch into smaller Purkinje fibers, which then transmit electrical impulses to the ventricular myocardium.

Answers A, B, C, and F do not match the description of branches at the terminal ends of the bundles of His.

Question 9

Circulatory shock caused by a drop in the amount of blood in the circulatory system is called _____ shock.

Accepted Answer

Hypovolemic shock is caused by a decrease in the volume of blood circulating in the body, often due to blood loss from trauma, surgery, or internal bleeding. Cardiogenic shock is caused by dysfunction of the heart muscle, anaphylactic shock is caused by severe allergic reactions, and septic shock is caused by severe infections.

Question 10

The period between the closure of the semilunar valve and the opening of the atrioventricular valves is called:

Accepted Answer

Isovolumetric ventricular relaxation occurs after the closure of the semilunar valves and before the opening of the atrioventricular valves, during which the ventricles relax but do not change in volume because all valves are closed.

Question 11

Which of the following factors would cause fluid to leave the blood vessel at the arterial end of the capillary?

Accepted Answer

At the arterial end of the capillary, the hydrostatic pressure of the blood is higher than the hydrostatic pressure of the interstitial fluid and the colloid pressure of the plasma proteins. This pressure difference causes fluid to leave the blood vessel and enter the surrounding tissues.

Question 12

Circulatory shock caused by the effects of infectious agents is called _____ shock.

Accepted Answer

Septic shock is caused by the release of toxins from infectious agents, such as bacteria, viruses, and fungi. This can lead to severe inflammation and damage to blood vessels, causing widespread dilation and increased permeability, resulting in a decreased ability to maintain blood pressure and oxygen delivery to tissues. Cardiogenic shock is caused by dysfunction of the heart, hypovolemic shock by a loss of blood or fluids, and anaphylactic shock by a severe allergic reaction.

Question 13

The effect of what substance is to increase the total blood volume?

Accepted Answer

ADH (Antidiuretic Hormone) and Aldosterone both play roles in increasing blood volume. ADH does this by promoting water reabsorption in the kidneys, leading to increased blood volume. Aldosterone increases blood volume by enhancing sodium retention, which in turn increases water retention.

Question 14

Which of the following statements is not true of the cardiovascular system?

Accepted Answer

The statement that all parts of the body must be equally supplied with blood is not true. Different tissues and organs have varying demands for blood supply depending on their metabolic activity and function. Blood flow is regulated and directed primarily to areas with the highest demand at any given time.

Question 15

The period during which blood is pumped out of the atria and into the ventricles is called:

Accepted Answer

Atrial systole is the period of time when the atria contract and pump blood into the ventricles. This phase is followed by ventricular systole when the ventricles contract and pump the blood out of the heart.

Question 16

When trying to stop arterial bleeding by applying pressure,why is it necessary to apply pressure between the bleeding part and the heart?

Accepted Answer

Arteries carry oxygenated blood from the heart to the various parts of the body. When there is arterial bleeding, applying pressure between the bleeding part and the heart can cut off the source of blood flow to that point by blocking the flow of blood from the heart to the injured area. This helps to slow down or stop the bleeding, thereby reducing the risk of further blood loss and increasing the chances of survival. Venous blood pressure and the contraction and relaxation of the atria are not relevant in this context. Option B is also incorrect as blocking arterial flow would increase blood pressure, not reduce it.

Question 17

Which part of the conduction system of the heart is referred to as the pacemaker?

Accepted Answer

The Sinoatrial node is known as the pacemaker of the heart, as it is the natural pacemaker that controls the heart rate. It is located in the right atrium and generates electrical impulses that initiate the heartbeat, which is then propagated through the conduction system of the heart, including the Atrioventricular node, Atrioventricular bundles, and Purkinje fibers. However, none of these other parts are specifically referred to as the pacemaker.

Question 18

Match each part of the conduction system of the heart to the description of its location or function.
-structure that is located below the atrial epicardium at its junction with the superior vena cava

Accepted Answer

The sinoatrial node is located below the atrial epicardium at its junction with the superior vena cava and is responsible for initiating the electrical impulses that regulate heart rate.

Answer: B 
 The atrioventricular node is located in the lower part of the atrial septum and receives the electrical impulses from the sinoatrial node before transmitting them to the ventricles.

Answer: E 
 The bundles of His are specialized fibers that travel down the interventricular septum and divide into the left and right bundle branches, which conduct the electrical impulses to the purkinje fibers.

Answer: F 
 The internodal bundles are specialized fibers that conduct the electrical impulses through the atrial muscle and help coordinate the contraction of the atria.

Answer: A 
 The interatrial bundles are specialized fibers that connect the sinoatrial node to the atrioventricular node and help coordinate the transmission of electrical impulses between the two nodes.

Answer: D 
 The Purkinje fibers are specialized fibers that distribute the electrical impulses throughout the ventricular muscles, causing ventricular contraction.

Question 19

Which of the following factors would cause fluid to be reabsorbed into the blood vessel at the venous end of the capillary?

Accepted Answer

At the arterial end of the capillary, blood has higher hydrostatic pressure than the interstitial fluid, which forces fluid out of the capillary. However, at the venous end, the hydrostatic pressure of the blood decreases, while the colloid pressure of plasma proteins and the hydrostatic pressure of the interstitial fluid remain relatively constant. As a result, the reabsorption of fluid into the blood vessel at the venous end is primarily driven by the higher colloid pressure of the plasma proteins and the hydrostatic pressure of the interstitial fluid, which push fluid back into the capillary. Therefore, both B (high colloid pressure of the plasma proteins) and C (hydrostatic pressure of the interstitial fluid) would cause fluid to be reabsorbed into the blood vessel at the venous end of the capillary.

Question 20

Which of the following tasks must the circulation control mechanism accomplish?

Accepted Answer

The circulation control mechanism must not only maintain circulation (choice A), but also be able to vary the volume and distribution of the blood circulated (choice B) in response to changing conditions such as exercise or injury. It does not necessarily ensure that all cells receive the same amount of blood (choice C), as some tissues may have higher metabolic demands and require more blood flow.

Quiz 22: B: Physiology of the Cardiovascular System