Question 1

What are blood vessels that normally bypass capillary beds are called?

Accepted Answer

Metarterioles are blood vessels that directly connect arterioles and venules, bypassing the capillary beds.

Question 2

The pressure gradient for blood flow through the systemic circuit is the mean arterial pressure.

Accepted Answer

The pressure gradient for blood flow through the systemic circuit is indeed the mean arterial pressure (MAP), which is the driving force for blood flow throughout the body, excluding the pulmonary circuit.

Question 3

What structures of the cardiovascular system are innervated by the sympathetic nervous system, but are NOT by the parasympathetic nervous system?

Accepted Answer

The sympathetic nervous system innervates the ventricular myocardium, arteriolar smooth muscle, and venous smooth muscle, providing regulatory control over heart rate, contractility, and vascular tone. The parasympathetic nervous system does not innervate the ventricular myocardium or the smooth muscle of arteries and veins, focusing instead on areas like the SA and AV nodes for heart rate modulation.

Question 4

The flow equation is: flow = pressure gradient × resistance.

Accepted Answer

The correct flow equation is: flow = pressure gradient / resistance.

Question 5

What is a drop in mean arterial pressure that results from standing up called?

Accepted Answer

Orthostatic hypotension is the medical term for a drop in blood pressure that occurs when a person stands up from sitting or lying down. It can cause dizziness or lightheadedness due to the sudden decrease in blood flow to the brain.

Question 6

In response to a decrease in the stretch of a baroreceptor, sympathetic nervous activity will while________ parasympathetic nervous activity will________ .

Accepted Answer

When the stretch of a baroreceptor decreases, it indicates a drop in blood pressure. The body compensates by increasing sympathetic nervous activity to raise blood pressure and decreasing parasympathetic activity to allow for this increase.

Question 7

Resistance is lower in the pulmonary circuit than in the systemic circuit.

Accepted Answer

The pulmonary circuit, which carries blood between the heart and lungs, has lower resistance compared to the systemic circuit, which circulates blood between the heart and the rest of the body. This is because the pulmonary vessels are shorter and wider, and the overall path of blood flow is shorter, leading to less resistance.

Question 8

What is bulk flow of fluid from inside a capillary into interstitial fluid called?

Accepted Answer

Filtration is the process by which fluid moves from the inside of a capillary into the surrounding interstitial fluid, driven by hydrostatic pressure differences. This is a key mechanism in the exchange of water and solutes between blood and tissues.

Question 9

An increase in the stretch of a baroreceptor will cause venomotor tone to________ while ventricular contractility will________ .

Accepted Answer

An increase in the stretch of a baroreceptor indicates increased blood pressure, leading to a decrease in venomotor tone and a decrease in ventricular contractility as part of the baroreflex to lower blood pressure.

Question 10

Flow through the pulmonary circuit is less than that through the systemic circuit due to a smaller pressure gradient.

Accepted Answer

Both the pulmonary and systemic circuits pump the same volume of blood, but the pressure gradient in the pulmonary circuit is lower, allowing for gentler blood flow through the lungs.

Question 11

What is the fluid within the lymphatic vessels called?

Accepted Answer

The fluid within the lymphatic vessels is called lymph. It is a clear, watery fluid that contains white blood cells, especially lymphocytes, which are essential for the immune system.

Question 12

Calculate the net filtration pressure given the following information: capillary blood pressure = 40 mm Hg; interstitial fluid hydrostatic pressure = 2 mm Hg; plasma osmotic pressure = 20 mm Hg; and interstitial fluid osmotic pressure = 5 mm Hg. Does filtration or absorption occur across this capillary wall?

Accepted Answer

The answer of Calculate the net filtration pressure given the...

Question 13

Which of the following is the equation relating cardiac output, mean arterial pressure, and total peripheral resistance?

Accepted Answer

The equation relating cardiac output (CO), mean arterial pressure (MAP), and total peripheral resistance (TPR) is MAP = CO × TPR. This equation illustrates that the mean arterial pressure is directly proportional to both the cardiac output and the total peripheral resistance.

Question 14

Smooth muscle in the veins has what type of adrenergic receptor?

Accepted Answer

Smooth muscle in the veins primarily has alpha adrenergic receptors, which respond to the neurotransmitter norepinephrine, leading to vasoconstriction.

Question 15

The factor having the greatest influence on resistance to blood flow is the radius of the blood vessels.

Accepted Answer

The resistance to blood flow is most significantly influenced by the radius of the blood vessels due to the principle that resistance is inversely proportional to the fourth power of the vessel's radius, as described by Poiseuille's law.

Question 16

Epinephrine triggers vasodilation by binding to which receptors and vasoconstriction by binding to which receptors?

Accepted Answer

Epinephrine causes vasodilation by binding to beta₂ receptors and vasoconstriction by binding to alpha receptors.

Question 17

The more proteins in blood, the higher the blood viscosity.

Accepted Answer

Proteins, especially fibrinogen and globulins, increase the viscosity of blood because they enhance the thickness and stickiness of the blood, making it flow more slowly.

Question 18

Where are the arterial baroreceptors located?

Accepted Answer

Arterial baroreceptors, which are crucial for regulating blood pressure, are located in the aortic arch and carotid sinuses (carotid arteries). These receptors sense changes in arterial pressure and send signals to the brain to adjust blood pressure accordingly.

Question 19

To produce angiotensin II, what must be secreted from the kidney to convert angiotensinogen to angiotensin I, which is then converted to angiotensin II by angiotensin converting enzyme?

Accepted Answer

Renin is secreted by the kidneys and is responsible for converting angiotensinogen, which is produced by the liver, into angiotensin I. Angiotensin I is then converted into angiotensin II by the angiotensin-converting enzyme (ACE), primarily in the lungs.

Question 20

What are the two functions of increasing blood flow to the skin during exercise?

Accepted Answer

Increasing blood flow to the skin during exercise helps dissipate heat and provides energy for sweat production.

Quiz 14: The Cardiovascular System: Blood Vessels, Blood Flow, and Blood Pressure