Chapter 14

Given the following information, calculate the net filtration pressure: capillary hydrostatic pressure = 30 mm Hg; interstitial fluid hydrostatic pressure = 5 mm Hg; capillary oncotic pressure = 25 mm Hg; and interstitial fluid oncotic pressure = 10 mm Hg.

10 mm Hg, favoring filtration

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?

23 mm Hg; filtration

________ are responsible for the detection of mean arterial pressure.

Arterial baroreceptors

Fenestrated capillaries are unique in their ability to

allow relatively large molecules to pass between endothelial cells.

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

alpha

What type of adrenergic receptor is found in the smooth muscle of most systemic arterioles?

alpha only

Which of the following will NOT occur as a consequence of the activation of the baroreceptor reflex that would occur in response to an increased heat load within the body?

an increase in resistance within the skin vasculature

What is the fluid within the lymphatic vessels called?

lymph

What is the driving force for blood flow through the systemic circuit?

mean arterial pressure

The portion of osmotic pressure exerted by ________ in the blood is known as colloid osmotic pressure (or oncotic pressure).

proteins

The respiratory pump facilitates the return of blood to the heart by

raising the pressure gradient between abdominal and thoracic veins during inspiration.

The hormone vasopressin acts in the short term to ________ and in the long term to ________, thereby increasing mean arterial pressure.

vasoconstrict arterioles : decrease urine outflow

Oxygen has what effect on systemic arterioles?

vasoconstriction

Which of the following does NOT occur in response to baroreceptors detecting an increase in mean arterial pressure?

vasoconstriction

Carbon dioxide has what effect on systemic arterioles?

vasodilation

Nitric oxide has what effect on systemic arterioles?

vasodilation

Which of the following has high compliance, allowing it to hold a large volume of blood with little change in pressure?

vein

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

ventricular myocardium, arteriolar smooth muscle and venous smooth muscle

Veins functions as ________ reservoirs due to their ________ compliance.

volume : high

A person goes to the doctor and is told his blood pressure is 90/60 and his pulse is 80. Which of the following is FALSE? A) Pulse pressure is 80 mm Hg. B) Heart rate is 80. C) Diastolic pressure is 60. D) Systolic pressure is 90 mm Hg. E) Mean arterial pressure is 70 mm Hg.

Pulse pressure is 80 mm Hg.

The chronic elevation in arterial pressure (hypertension) that occurs in many individuals results in

a gradual increase in pressure that resets the baroreceptors.

Which of the following can cause vasoconstriction?

angiotensin II

During exercise, which of the following tissues receive less blood flow compared to resting conditions?

astrointestinal tract only

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

beta2 : alpha

Which of the following is NOT altered within seconds to minutes of the baroreceptor reflex being activated?

blood volume

Where are the arterial baroreceptors located?

coronary sinuses and aortic arch

The primary mechanism for exchange of substances across the capillary wall is

diffusion.

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

facilitate dissipation of heat; provide energy for sweat production

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

filtration

As mean arterial pressure increases, the ________, informing the medulla oblongata that blood pressure has indeed increased.

frequency of action potentials from the baroreceptors increases

Which of the following is a decrease in tissue oxygen?

hypoxia

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

increase : decrease

What is a decrease in blood flow that is less than what is necessary to keep up with metabolic demands called?

ischemia

Which of the following is a decrease in blood supply to the tissue such that it does not meet the metabolic demands of the tissue?

ischemia

Information about mean arterial pressure is integrated within what area of the central nervous system?

medulla oblongata

Where is the cardiovascular control center?

medulla oblongata

Parasympathetic nervous activity has what effect on systemic arterioles?

neither vasoconstriction and vasodilation

Bradykinin causes vasodilation by stimulating the release of what substance from endothelial cells?

nitric oxide

Which of the following substances is continuously secreted by endothelial cells and causes vasodilation?

nitric oxide

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

orthostatic hypotension

Which of the following equations correctly relates flow, pressure, and resistance?

pressure = flow × resistance

The effects of epinephrine on vascular resistance are dependent upon which of the following?

relative distribution of alpha and beta receptors

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?

renin

Arteriolar smooth muscle in which of the following tissues tends to have beta2 receptors predominating?

skeletal muscle

During exercise, which organs receive an increase in the proportion of cardiac output delivered to them?

skeletal muscle, heart, and skin

At rest, the greatest proportion of blood volume is present within the

systemic veins.

Angiotensin II has what effect on systemic arterioles?

vasoconstriction

Sympathetic nerves have what effect on systemic arterioles?

vasoconstriction

Vasopressin has what effect on systemic arterioles?

vasoconstriction

Which of the following is an incorrect description of a blood vessel type?

Capillary walls are comprised of only two cell layers, minimizing the distance for exchange.

The high compliance of veins allows them to

accommodate large volumes of blood with little change in pressure.

Which of the following descriptions of the autonomic innervation of the cardiovascular system is FALSE? A) Only sympathetic neurons provide significant innervation of the contractile cells of the heart. B) Only sympathetic neurons innervate smooth muscle in veins. C) Both sympathetic and parasympathetic neurons innervate smooth muscle in arterioles. D) Both sympathetic and parasympathetic neurons innervate the SA node. E) Sympathetic activity increases cardiac output, whereas parasympathetic activity decreases cardiac output.

Both sympathetic and parasympathetic neurons innervate smooth muscle in arterioles.

________ describes the movement of fluid out of the capillary, while ________ describes the movement of fluid into the capillary.

Filtration : absorption

Which of the following accurately describes sympathetic control of blood vessels in the skin during thermoregulation?

Heat causes a decrease in sympathetic activity, resulting in vasodilation.

Which of the following inaccurately represents normal forces across capillary walls?

Interstitial fluid hydrostatic pressure increases from arteriole end to venous end.

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

MAP = CO × TPR

Which of the following comparisons between systemic capillaries and lymphatic capillaries is TRUE? A) Pressure is higher in lymphatic capillaries. B) Blood cells are found in both types of capillaries. C) Fluid enters systemic capillaries from systemic arterioles; fluid enters lymphatic capillaries from lymphatic veins. D) Walls of systemic capillaries are more permeable. E) Net filtration occurs across systemic capillaries; net absorption occurs across lymphatic capillaries.

Net filtration occurs across systemic capillaries; net absorption occurs across lymphatic capillaries.

Given that the net filtration of fluid out of the capillaries averages about 3 liters per day, how is blood volume maintained in light of this apparent fluid loss?

The lymphatic system returns filtered fluid to the blood.

Which of the following structures contains high pressure baroreceptors?

both the aortic arch and carotid sinus

What region of the cardiovascular system contains valves?

both the heart and veins

Which of the following is the smallest of blood vessels with thin walls allowing for ready exchange of material between blood and tissue?

capillary

Which of the following equations is correct?

cardiac output = stroke volume × heart rate

Despite seeming counterproductive, an increase in arterial carbon dioxide levels activates ________, which causes a(n) ________ in heart rate and a(n) ________ in total peripheral resistance.

chemoreceptors: decrease : decrease

Which of the following would increase blood flow through a capillary bed?

contraction of smooth muscle in the metarterioles bypassing the capillary bed

The long-term regulation of arterial blood pressure involves the

control of blood volume by the kidneys.

Which of the following can cause edema?

damage to capillary walls only

Drugs that block angiotensin-converting enzyme would cause which of the following?

decreased mean arterial pressure

Which of the following would NOT increase mean arterial pressure?

decreased parasympathetic activity effects on the arterioles

Mean arterial pressure can be increased by all of the following EXCEPT

decreasing end-diastolic volume.

An increase in the volume of blood ejected from the heart, with no change in total peripheral resistance, would

elevate mean arterial pressure.

An increase in total peripheral resistance, in the absence of any change in cardiac output, would

elevate mean arterial pressure.

Which of the following substances is secreted by endothelial cells and causes vasoconstriction?

endothelin-1

What is the equation relating flow to resistance and a pressure gradient?

flow = pressure gradient / resistance

Which of the following would decrease mean arterial pressure?

increase in arteriole diameter

Which of the following would increase the rate of blood flow through a blood vessel?

increased pressure of the blood entering the vessel

In cardiac and skeletal muscle vasculature, the distribution of alpha and beta receptors is such that epinephrine will

induce a dilation that increases blood flow to these tissues.