Blood Vessels and Circulation - Mace Flashcards Preview

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Flashcards in Blood Vessels and Circulation - Mace Deck (34)
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1
Q

The tunica intima of an artery or vein consists of what two layers?

A

Endothelium and subendothelial layers

2
Q

What comprises the tunica media of a blood vessel? Is the tunica media thicker in an artery or vein?

A

It consists of smooth muscle. It is thicker in arteries than veins

3
Q

Are valves present in veins, arteries, or both?

A

Veins only

4
Q

What is the significance of the tunica externa?

A

The tunica externa has tiny blood vessels that supply the tunica media with blood.

5
Q

What are the 3 types of arteries? Give an example of each.

A

Elastic arteries - allow “balloon” effect. Ex: aorta, subclavian, common illiac
Muscular arteries - distribute blood to specific organs. Ex: femoral artery, splenic artery
Arteriole - the small arteries just before capillary beds.

6
Q

Do arteries or veins have a thicker tunica externa?

A

Veins

7
Q

There are 3 types of capillaries, what are they?

A

Continuous, fenestrated, and sinusoid

8
Q

What type are the majority of capillaries in the body?

A

Continuous capillaries

9
Q

What molecules can pass though a continuous capillary?

A

Blood gasses and H2O for the most part

10
Q

What makes fenestrated capillaries different from continuous capillaries? Where are they located?

A

Fenestrated capillaries have tiny holes in the membrane (called fenestrations) that aid in absorption and secretion. They are located in exocrine glands and kidneys

11
Q

What makes a sinusoid capillary different from other capillaries? Where are they found?

A

Sinusoid capillaries have large openings and a discontinuous basement membrane. It allows for large molecules and whole cells to pass through. They are located in the liver, spleen, and red bone marrow.

12
Q

What structures control blood flow through the capillary bed?

A

Precapillary sphincters

13
Q

What are arterial anastomoses? Where might you find them?

A

They are alternative pathways for blood to reach a target. One place they are found is the brain, in an effort to maintain perfusion if something goes wrong.

14
Q

What are venous anastomoses?

A

Pathways of alternative drainage of blood.

15
Q

What is a shunt?

A

A shunt is an anastomosis between an artery and a vein. The blood does not go through a capillary bed to reach to venous system.

16
Q

What is a portal system?

A

A portal system is where there are 2 capillary beds between the arterial and venous systems.

17
Q

Where in the body is a portal system found? What its purpose?

A

A portal system is found in the liver, called the hepatic portal system. The first capillary bed is where gas exchange occurs. The second capillary bed is where the liver processes blood.

18
Q

At rest, which of the following holds the largest percentage of blood?

a) Pulmonary circulation
b) systemic circulation
c) the heart
d) the liver

A

b) systemic circulation

19
Q

Which of the following portions of the systemic circulation holds the largest volume of blood at rest?

a) systemic capillaries
b) systemic arteries
c) systemic veins
d) systemic lymph vessels

A

c) systemic veins

20
Q

Which of the following do not feed into the hepatic portal vein?

a) inferior mesenteric vein
b) superior mesenteric vein
c) renal vein
d) splenic vein

A

c) renal vein

* * hepatic portal vein does not receive blood from kidneys or gonads

21
Q

Which of the following are rich in the blood of the hepatic portal vein?

a) Waste products from spleen
b) oxygen
c) nutrients from GI tract
d) two of the above
e) all of the above

A

d) (a and c)

22
Q

In blood vessels, cross sectional area is highest in the _______, leading to ________ blood velocity.

A

capillaries, decreased

23
Q

The dicrotic notch in pulse pressure signifies ________

A

the aortic valve closing

24
Q

In the arterial end of a capillary, the net filtration pressure is ______ (positive/negative) and fluid flows ______ (in/out).

A

positive (14mmHg)

out

25
Q

At the venous end of a capillary, the net filtration pressure is ______ (positive/negative) causing fluid to flow ___ (in/out).

A

negative (-5mmHg)

in

26
Q

What has a lower BP, the superior vena cava or the dorsalis pedis artery?

A

superior vena cava has a lower BP.

BP is veins is always lower than arteries

27
Q

Which of the following factors are directly proportional to blood pressure?

a) cardiac output
b) blood volume
c) peripheral resistance
d) two of the above
e) all of the above

A

e) all of the above

28
Q

By what mechanism does exercise decrease blood pressure?

A

Exercise promotes angiogenesis, which creates more vessels and short vessels leading to decreased peripheral resistance.

29
Q
For each of the following, does it increase or decrease BP?
Increased cardiac output
vasodilation
vasoconstriction
Increased blood viscosity
Longer vessel length
A
Increased cardiac output - increase BP
vasodilation - Decrease BP
vasoconstriction - Increase BP
Increased blood viscosity - Increase BP
Longer vessel length - Increase BP
30
Q

What 3 autonomic reflexes effect blood pressure?

A

Baroreflex
Chemoreflex
Medullary ischemic reflex

31
Q

Where are the receptors for the baroreflex? What do the respond to?

A

In the carotid and aortic sinus, the baroreceptors measure pressure/stretch

32
Q

Where are the receptors for the chemoreflex? What stimulus do the chemoreceptors respond to?

A

In the carotid and aortic bodies, the chemoreceptors sense O2, CO2, and pH.

33
Q

What is the medullary ischemic reflex?

A

The medulla of the brain senses decreased cerebral blood flow leading to systemic vasoconstriction and increased BP

34
Q

Does the sympathetic nervous system increase or decrease BP?

What about the parasympathetic nervous system?

A

Sympathetic : increase BP

Parasympathetic : decrease BP