Ch. 14 Review Blood Vessels, Blood Flow, and Blood Pressure

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

10 mm Hg, favoring filtration

The flow equation is: flow = pressure gradient * resistance

False

Which equations correctly relates flow, pressure, and resistance?

Pressure = Flow * Resistance

The more proteins in blood, the higher the blood viscosity

True

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

True

The chronic elevation in arterial pressure (hypertension) that occurs in any individuals results in ___.

a gradual increase in pressure that resets the baroreceptor

The high compliance of veins allows them to ___.

accommodate large volumes of blood with little change in pressure

During exercise, carbon dioxide produced by muscle cells causes vasodilation in skeletal muscle. This is an example of ___.

active hyperemia

What is an increase in blood flow in response to an increase in tissue metabolic activity called?

active hyperemia

Which is an important vasodilator in coronary arteries?

adenosine

Fenestrated capillaries are unique in their ability to ___.

allow relatively large molecules to pass between endothelial cells

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

alpha only

The increase in stroke volume that occurs during exercise is caused primarily by ___.

an increase in myocardial contractility

Which 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

Which can cause vasoconstriction?

angiotensin II

___ are responsible for the detection of mean arterial pressure.

arterial baroreceptors

The pulsatile nature of blood pressure is greatest in which blood vessels?

arteries

Blood flow velocity is greatest in the ___ and slowest in the ___.

arteries; capillaries

In the circulatory system, the largest pressure drop occurs across which blood vessels?

arterioles

Resistance to blood flow is regulated primarily by what blood vessels?

arterioles

The contractile activity of smooth muscle cells within which type of blood vessel is primarily involved in the control of the organ blood flow and mean arterial pressure?

arterioles

Due to their location, baroreceptors in the large systemic veins and the heart function primarily to monitor ___.

blood volume

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

blood volume

Which is an inaccurate description of autonomic innervation of the cardiovascular system?

both sympathetic and parasympathetic neurons innervate smooth muscle in arterioles

Which 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

Blood pressure is usually estimated from indirect measurements of the pressure in what structure?

brachial artery

What organ has capillaries that are the most restrictive to movement of hydrophilic solutes?

brain

An increase in sympathetic nervous activity to arterioles will have little effect on the vasculature of the ___.

brain and heart

The total cross-sectional area is greatest in which blood vessels?

capillaries

Under normal conditions, which Starling forces favor filtration?

capillary hydrostatic pressure and interstitial fluid osmotic pressure

Which is an INCORRECT description of a blood vessel type?

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

Which would cause relaxation of precapillary sphincters?

carbon dioxide

Which equations is correct?

cardiac output = stroke volume * heart rate

An increase in arterial carbon dioxide levels activates ___, which causes a ___ in heart rate and a ___ in total peripheral resistance.

chemoreceptors; decrease; decrease

What is/are the components of a blood vessel's extracellular matrix that provides the tensile strength required to withstand pressure?

collagen

What is a measure of the change in vascular volume as pressure within the vessel is altered?

compliance

Which would increase blood flow through a capillary bed?

contraction of smooth muscle in met arterioles bypassing the capillary bed

Which best classifies the baroreceptor reflex?

cranial; autonomic; innate; polysynaptic

Which can cause edema?

damage to capillary walls only

Drugs that block angiotensin-converting enzyme would cause which?

decrease mean arterial pressure

Which would NOT increase mean arterial pressure?

decreased parasympathetic activity to the arterioles

Mean arterial pressure can be increased by all except ___.

decreasing end-diastolic volume

Glucose moves across continuous capillary walls by what mechanism?

diffusion

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

diffusion

What component of artery walls allows them to store energy that is later used to maintain continuous blood flow through the circulatory system?

elastin

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

The lumen of every blood vessel is lined by a monolayer of what cell type?

endothelial cells

Which substance is secreted by endothelial cells and causes vasoconstriction?

endothelin-1

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

filtration; absorption

Valves, which are ___, maintain the unidirectional movement of blood, thereby facilitating the return of blood to the heart.

found only in peripheral veins

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

frequency of action potentials from the baroreceptors increases

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

gastrointestinal tract only

In comparison to the systemic circuit, the pulmonary circuit ___.

has lower resistance to blood flow

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

heat causes a decrease in sympathetic activity, resulting in vasodilation

What is a decrease in tissue oxygen called?

hypoxia

Which would decrease mean arterial pressure?

increase in arteriole diameter

The increase in blood flow to active skeletal muscle relative to other organs is largely caused by the ___.

increase in local metabolic factors within the muscle

In response to a decrease in tissue metabolic activity, tissue oxygen concentrations ___, which causes a ___.

increase; constriction of the arterioles

The reduction in organ blood flow that results from a decrease in mean arterial pressure would be exacerbated by the ___ that occurs as a consequence of the baroreceptor reflex.

increased peripheral resistance

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

increased pressure of the blood entering the vessel

Which will NOT occur in response to a decrease in the extent of stretch detected by a baroreceptor?

increased urine flow

Which is NOT a mechanism that alerts the balance between filtration and absorption in the body?

increasing hydrostatic pressure gradient in cases of enhanced interstitial protein

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

induce a dilation that increases blood flow to these tissues

Which inaccurately represents normal forces across capillary walls?

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

Arteries have ___ compliance and ___ resistance.

low; low

Foreign materials are filtered out of the lymphatic fluid by what type of cell located within the lymph nodes?

macrophages

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

mean arterial pressure

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

A decrease in pressure within an arteriole will initiate a ___.

myogenic response

Which comparisons between systemic capillaries and lymphatic capillaries is true?

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

Which substance is secreted by endothelial cells and causes vasodilation?

nitric oxide

Which accurately compares active hyperemia to reactive hyperemia?

one is caused by increased metabolic activity, the other in response to release of an occlusion to blood flow.

An increase in the concentration of which within the interstitial space surrounding an arteriole would cause that vessel to constrict?

oxygen

Which chemical's concentration is NOT increased by an elevation in metabolic activity?

oxygen

The elastic nature of the largest blood vessel's walls allows them to act as a ___, maintaining the driving force for blood flow while the heart is relaxed during diastole.

pressure reservoir

The portion of osmotic pressure exerted by ___ in the blood is known as colloid osmotic pressure.

proteins

A person goes to the doctor and is told his blood pressure is 90/60 and his pulse is 80. Which is FALSE?

pulse pressure is 80 mm Hg

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

raising the pressure gradient between abdominal and thoracic veins during inspiration

Which is NOT a mechanism that enables molecules to move across capillary endothelial cells?

rapid diffusion of water-soluble molecules across endothelial cells

What is the purpose of extrinsic control of arteriolar smooth muscle contractile activity?

regulate mean arterial pressure

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

relative distribution of alpha and beta receptors

Chemicals released by metabolically active cells will cause?

relaxation of arteriolar smooth muscle to increase blood flow

Any change in the relative distribution of cardiac output to an organ is typically due to changes in which?

resistance of that organ's vascular bed

Which describes rhythmic changes in sympathetic and parasympathetic activity that affect heart rate coincident with respiration?

respiratory sinus arrhythmia

Arteriolar smooth muscle in what tissue tends to have beta2 receptors?

skeletal muscle

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

skeletal muscle, heart, and skin

Which would decrease central venous pressure?

standing up

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

systemic veins

The long-term regulation of arterial blood pressure involves ___.

the control of blood volume by the kidneys

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

the lymphatic system returns filtered fluid is returned to the blood

Which statements about smooth muscle in arterioles is FALSE?

the muscle is multi-unit smooth muscle

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

vasoconstriction

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

vasoconstriction arterioles; decrease urine outflow

Which is NOT a component of the microcirculation?

veins

The blood vessels of largest diameter are the ___; the blood vessels with the thickest walls are the ___.

veins; arteries

Exchange between blood and interstitial fluid occurs across capillaries and, to a lesser extent, ___.

venules

Veins functions as ___ reservoirs due to their ___ compliance.

volume; high