A&P Chapter 20

A

Blood vessels that connect two capillary networks are called

A.

portal systems.

B.

anastomoses.

C.

arterial systems.

D.

veins.

E.

capillary plexuses.

C

The tissue layer of a vessel that differs most in thickness when comparing arteries and veins is the

A.

tunica externa.

B.

tunica adventitia.

C.

tunica media.

D.

tunica interna.

E.

tunica intima.

B

These have the most control of perfusion of a capillary bed.

A.

muscular arteries

B.

precapillary sphincters

C.

elastic arteries

D.

sinusoids

E.

fenestrated capillaries

E

These structures, present in medium-sized veins, prevent backflow of blood.

A.

precapillary sphincters

B.

venous tunica

C.

skeletal muscles

D.

fenestrations

E.

venous valves

A

Pulse pressure equals the systolic pressure minus the diastolic pressure. Mean arterial blood pressure (MAP) equals the sum of the diastolic pressure plus one-third of the pulse pressure. What is the MAP in an individual with a blood pressure of 150/90?

A.

110

B.

120

C.

130

D.

150

D

The baroreceptors

A.

transmit signals continually to the brainstem.

B.

increase their signaling rate when the blood pressure rises.

C.

excite the vagal nerves to the heart and dilate the arteries to lower BP.

D.

All of the above.

D

All of these factors may increase peripheral resistance except

A.

blood viscosity.

B.

length of vessel.

C.

radius of vessel.

D.

blood type.

E.

polycythemia.

C

Reduced capillary reabsorption of fluid can lead to edema. Which of the following does not contribute to edema?

A.

liver disease

B.

dietary protein deficiency

C.

extreme muscular activity

D.

kidney diseases

B

The most important mechanism of exchange between blood and tissue fluid is ________________.

A.

transcytosis

B.

diffusion

C.

filtration

D.

active transport

A

Which of the following types of low venous return (LVR) shock occurs when released histamine causes extensive generalized vasodilation?

A.

anaphylactic shock

B.

septic shock

C.

hypovolemic shock

D.

neurogenic shock

C

Venous pooling in a soldier standing at attention for a prolonged time occurs mainly when this mechanism fails.

A.

cardiac suction

B.

respiratory pump

C.

skeletal muscle pump

D.

gravity

E.

pressure gradient

D

The venous return of blood back to the heart is encouraged by

A.

constriction of veins in the legs.

B.

a drop in internal pressure in the abdomen during inhalation.

C.

relaxation of skeletal muscle.

D.

gravity acting on the large veins above the heart.

A

This vein receives blood returning from all areas of the posterior thoracic wall before it empties into the superior vena cava.

A.

azygos vein

B.

right brachiocephalic vein

C.

hemiazygos vein

D.

accessory hemiazygous vein

E.

right internal jugular vein

B

The right gonadal vein empties into the inferior vena cava. Where does the left gonadal vein empty?

A.

It also empties into the inferior vena cava.

B.

the left renal vein

C.

the splenic vein

D.

the inferior mesenteric vein

E.

It empties into the right gonadal vein before it joins the inferior vena cava.

D

Which of the following is not one of the three major branches arising from the aortic arch?

A.

brachiocephalic trunk

B.

left common carotid artery

C.

left subclavian artery

D.

right common carotid artery

D

The internal carotid artery contributes blood directly to this circle of Willis artery.

A.

basilar

B.

vertebral

C.

spinal

D.

anterior cerebral

E.

posterior cerebral

E

Blood flows to the liver from the superior mesenteric vein through the ____ vein.

A.

hepatic

B.

celiac

C.

jugular

D.

gastroepiploic

E.

hepatic portal

E

Blood flowing from the dural sinus will eventually go through this vein immediately before continuing into the superior vena cava.

A.

internal jugular

B.

subclavian

C.

vertebral

D.

aorta

E.

brachiocephalic

B

The right common carotid receives its blood from this artery directly.

A.

right subclavian

B.

brachiocephalic

C.

aorta

D.

right cerebral

C

The artery which is the continuation of the femoral artery after it passes to the posterior side of the thigh is the

A.

posterior femoral.

B.

posterior tibial.

C.

popliteal.

D.

peroneal.

arteries

carry away from heart

arterioles

regulate BP

capillaries

exchange gasses and nutrients

venules

remove from heart

veins

carry back to heart

tunica media

thickest, smooth muscle layer of heart

tunica externa

anchors, provides passage for nerves collagen and elastic fibers

conducting

the biggest arteries. ex) carotid, aorta, subclavian

distributing

arteries that distribute blood to specific organs

resistance

arteries that are variable in location and number

carotid sinuses

baroreceptors that monitor BP

Carotid bodies

chemoreceptors that monitor changes in blood composition

aortic bodies

one to three chemoreceptors located on the aortic arch

continuous

capillaries that occur in most tissues including skeletal

continuous

capillaries made out of epithelial tissue held together by tight junctions

fenestrated

capillaries riddled with patches of filtration pores

sinusoids

irregular blood filled spaces in the liver, bone marrow, spleen, and other organs

portal system systems

blood flows through two consecutive capillary networks before returning to the heart