Chapter 21 Blood Vessels and Circulation Flashcards

Comprehensive flashcards for reviewing blood vessels and circulation concepts.

What is the muscular layer in the wall of a blood vessel called?

Tunica media

Compared to arteries, how do veins differ in terms of wall thickness?

Veins have thinner walls.

What are capillaries that have a complete lining called?

Continuous capillaries

What are the smallest arterial branches called?

Precapillary arterioles

What is the layer between the tunica media and the tunica externa in a large artery called?

External elastic membrane

Where does the thoroughfare channel end?

Venule

Which layer of a vessel contains collagen fibers with scattered bands of elastic fibers?

Tunica externa

After blood leaves the capillaries, where does it enter?

Venules

Which layer of a blood vessel contains concentric sheets of smooth muscle tissue?

Tunica media

What are the large vessels that return blood to the heart called?

Veins

In arteries, what is the thick layer of elastic fibers associated with the tunica intima called?

Internal elastic membrane

Which is the innermost layer of a blood vessel?

Tunica intima

Venoconstriction reduces blood in the venous system, which the volume in the arterial and capillary systems.

increases

What are venous valves responsible for?

Channeling blood toward the heart

Venae cavae are the largest of what type of vessel?

Vein

What layer of the arteriole wall produces vasoconstriction?

Tunica media

Relative to the lumen, which vessel has the thickest tunica media?

Arterioles

Which of the following is an example of an elastic artery?

The subclavian

Where would you expect to find fenestrated capillaries?

The pituitary gland

If a tissue sample displays many large flattened spaces lined by fenestrated endothelium, where did it likely come from?

Liver

Name factors that increase the risk of atherosclerosis

High cholesterol, lack of exercise, smoking, obesity

These vessels may be continuous or fenestrated.

Capillaries

What structure do RBCs move through single-file?

Capillary

What are capillaries with a perforated lining called?

Fenestrated capillaries

Where does exchange between a blood vessel and surrounding cells occur?

Capillaries

What kind of vessel is also called a resistance vessel?

Arteriole

What controls blood flow through a capillary?

Precapillary sphincter

The common iliac artery is an example of what type of artery?

Elastic

What lumen diameter would be typical of a muscular artery?

0.4 cm

Venoconstriction reduces the diameter of which vessel?

Vein

The brachial and femoral arteries are examples of what type of artery?

Muscular

What vessels contain elastic fibers in the walls that are stretched during systole?

Arteries

Which is most likely to result from an aneurysm in a brain artery?

Stroke

Complications related to arteriosclerosis account for roughly what percent of deaths in the United States?

50

What vessels hold the largest percentage of the blood supply?

Veins

Arteriosclerosis can lead to what?

Hypertension, stroke, coronary artery disease, myocardial infarction

A vein that measures 5 mm would be considered what?

Medium vein

The inferior vena cava is classified as what?

Large vein

Which of the following are the smallest venous vessels?

Venules

Blood moves forward through veins because of all of the following except

pumping by the smooth muscle in the wall of the vein

Which part of the vascular system functions as a blood reservoir and contains over 60% of the body's blood?

Veins

What is the correct order for the sequence of blood vessels in the systemic circuit, starting at the aorta?

4, 7, 2, 3, 1, 5, 6 (elastic arteries, muscular arteries, arterioles, capillaries, venules, medium veins, large veins)

Where does the main control of peripheral resistance occur?

Arterioles

What are the small vessels that capillaries drain into called?

Venules

What is resistance?

A force that decreases blood flow.

Total peripheral resistance is related to all of the following except:

Osmolarity of interstitial fluids

As blood travels from arteries to veins, what happens to the pressure?

Pressure drops.

Blood flow to a tissue will increase if the:

Arterioles dilate.

How is blood pressure determined?

Estimating the pressure needed to close off an artery with an external pressure cuff.

In what vessel is blood pressure the highest?

Artery

Blood pressure increases with all of the following except increased:

Parasympathetic innervation

Which of the following factors will increase the net filtration pressure to move fluid out of capillaries?

Both decreased plasma albumin and increased blood hydrostatic pressure

Where does the main control of peripheral resistance occur?

Arteriole

The vascular pressure that declines from roughly 35 mm Hg to about 18 mm Hg is the:

Capillary hydrostatic pressure

Clinically, the term blood pressure usually refers to what?

Arterial pressure

Averaged over a few heartbeats, venous return is cardiac output.

Equal to

Blood pressure is lowest in the:

Veins

Which of the following affects blood flow through the body?

blood viscosity, vessel diameter, turbulence, vascular resistance

If blood pressure doubled, the blood flow through a vessel would be:

Doubled.

In which of the following would the blood flow be highest?

A vessel 1.0 cm in diameter and 2 meters long

Each of the following factors would increase peripheral resistance except:

Vasodilation.

Each of the following factors would increase cardiac output except:

Increased blood concentration of glucose.

Turbulent blood flow occurs:

When there are irregularities in the vessel wall.

If a person has a blood pressure of 120/90, his mean arterial pressure would be mm Hg.

100

The continual movement of fluid through the interstitial spaces produced by capillary filtration serves which of the following functions?

accelerates the distribution of nutrients and hormones, assists the transport of insoluble substances that cannot enter the capillaries, helps carry toxins and bacteria to cells of the immune system, flushes hormones and wastes from the interstitial spaces

When a person rises quickly from a sitting position, what occurs?

the carotid baroreceptors become less active, venous return is decreased, reflex vasoconstriction of peripheral blood vessels occurs, heart rate is reflexively elevated

What is the difference between the systolic and diastolic pressures called?

Pulse pressure.

The blood colloid osmotic pressure mostly depends on the:

Concentration of plasma proteins.

Which of the following statements is false concerning the movement of fluid between capillaries and interstitial space?

The net filtration pressure is usually zero.

When renin is released from the kidney, what happens?

Angiotensinogen is converted into angiotensin I.

Each of the following will lead to a decrease in blood pressure except:

Release of renin.

Each of the following will cause an increase in blood pressure except:

Increased levels of ANP (atrial natriuretic peptide).

Each of the following changes will result in increased blood flow to a tissue except:

Increased hematocrit.

In comparison to a vessel with a large diameter, a vessel with a small diameter has:

A greater resistance to blood flow.

Which of the following equations shows the correct relation between blood flow (F), pressure (P), and resistance (R)?

F = P/R

As blood circulates from arteries into capillaries, the total cross-sectional area of capillaries

increases and causes the blood velocity to decrease

Which of the following is normally the greatest source acting against blood flow?

Vascular resistance

The force that moves fluid out of capillaries is pressure whereas the opposing force that moves fluid into capillaries is pressure.

hydrostatic; colloid osmotic

Some of the fluid that is forced out of capillaries is returned to the blood by the

lymphatic system

Blood colloid osmotic pressure is produced by:

Large non-diffusible proteins in the blood plasma.

Blood colloid osmotic pressure (BCOP) decreases in starving children because

starvation prevents the liver from producing enough protein to maintain BCOP

Calculate the net filtration pressure (NFP) with a blood hydrostatic pressure of 40 mm Hg and a blood colloid osmotic pressure of 25 mm Hg. Then determine if filtration or reabsorption occurs.

NFP = 15 mm Hg; filtration

Which of the following opposes the flow of blood back to the heart?

vascular resistance

As blood travels from arteries to veins,

pressure decreases

Which of the following affects blood flow through the body?

blood viscosity, turbulence, vascular resistance, vessel diameter

Edema may occur when

the plasma concentration of protein is reduced, capillary hydrostatic pressure is elevated, and the capillary endothelium permeability goes up.

Which of the following are characteristics of cardiovascular regulation?

Blood flow through tissues meets the demand for oxygen, Blood flow changes to match tissue responses, Changes occur without drastically altering blood pressure, Blood flow through tissues meets the demand for nutrients

Stimulation of the aortic baroreceptors reflexively results in

increased activity by the parasympathetic nervous system

Fear can result in

increased stimulation of the cardioaccelerator center by higher brain centers.

Elevated levels of the natriuretic peptide hormones ANP and BNP will produce increased

salt and water loss through the kidneys.

When carotid and aortic baroreceptors reduce their output,

both heart rate and stroke volume increase.

Increased levels of carbon dioxide in the blood will result in decreased

parasympathetic stimulation of the heart.

Vickie has a tumor that secretes excess amounts of the hormone aldosterone. Because of the elevated level of hormone, she exhibits

both an increase in blood pressure and an increase in stored sodium ion.

Which of the following conditions is least likely to lead to renin release?

hypertension

Which of the following changes does not occur during exercise compared to rest?

Skin blood flow is lower.

To defend blood volume against dehydration, the body

releases antidiuretic hormone (ADH).

ADH and aldosterone secretion are part of the body's long-term compensation for

a serious hemorrhage.

During exercise,

vasodilation occurs at the active skeletal muscles, venous return increases,both cardiac output and stroke volume increase, tissue perfusion to the digestive system decreases

In response to hemorrhage, there is .

mobilization of the venous reserve

During exercise,

venous return increases, both cardiac output and stroke volume increase, vasodilation occurs at the active skeletal muscles