Test 3 - Cardiovascular

Question 1

Systemic circulation

Answer 1

heart to body tissues and body tissue to heart

Question 2

Pulmonary circulation

Answer 2

heart to lungs and lungs to heart

Question 3

Portal circulation/systems

Answer 3

vein/arteriole between 2 capillary beds

Question 4

What are the three wall layers of vessels?

Answer 4

1. tunica intima
2. tunica media
3. tunica adventitia

Question 5

What is found in the tunica intima?

Answer 5

1. simple squamous epithelium
2. basal lamina (collagen & proteoglycans)
3. subendothelial layer (loose CT)

Question 6

What is found in the tunica media?

Answer 6

mainly smooth muscle

Question 7

What is found in the tunica adventitia?

Answer 7

mainly CT

Question 8

What is endothelium?

Answer 8

epithelium that lines blood vessels

Question 9

When discussing the 3 layers of vessels, which layers is most responsible for blood pressure maintenance?

Answer 9

tunica media (smooth muscle)

Question 10

What is vasodilation?

Answer 10

relaxing of smooth muscle (decrease resistance, decrease blood pressure, increase lumen size)

Question 11

Name a vasodilator.

Answer 11

Nitric oxide (NO)

Question 12

What is vasoconstriction?

Answer 12

contraction of smooth muscle (increase resistance, increase blood pressure, decrease lumen size)

Question 13

Name a vasoconstrictor.

Answer 13

ET-1 (endothelin 1), absence of NO

Question 14

Compare and contrast large arteries and large veins.

Answer 14

arteries: large tunica media, circular lumen
veins: large tunica adventitia, irregular lumen

Question 15

Why are there histological differences between arteries and veins?

Answer 15

from the difference of blood pressure - arteries have an increase in pressure to pump blood to the entire body therefore need more muscle

Question 16

What would you find in a microcirculatory bed?

Answer 16

arterioles, venules, AV shunts, capillaries, precapillary sphincters, thoroughfare channel

Question 17

What is a microcirculatory bed?

Answer 17

where arterioles regulate blood flow to capillary networks

Question 18

AV shunts and functions.

Answer 18

• allows blood to bypass capillaries
• arteriole-ventriole direct connection

Question 19

Steps of arteriole-ventriole direct connection

Answer 19

1. open shunt
2. close sphincter
3. blood doesn’t go to capillaries, uses bypass

Question 20

What tissues make up the epicardium?

Answer 20

mesothelium, CT, adipose (outside of heart)

Question 21

What tissues make up the myocardium?

Answer 21

cardiac muscle

Question 22

What tissues make up the endocardium?

Answer 22

3 layers:
1. inner (endothelium, CT)
2. middle (CT, smooth muscle)
3. deeper/subendocardial layer (CT, Purkinje cells)

Question 23

Describe the histology of the heart walls

Answer 23

cardiac muscle
fibrous skeleton for muscle attachment
internal conducting system

Question 24

Describe the histology of the heart valves

Answer 24

CT and and endocardium
Has 3 layers

Question 25

What are the 3 layers of the heart valve?

Answer 25

1. spongiosa: atrial side (collagen & elastic fibers)
2. fibrosa: middle (dense irregular CT)
3. ventricularis: ventricular side (dense irregular CT with elastic fibers) - continuous with chordae tendinae

Question 26

How does the histology of the heart walls and heart valves make sense when regarding their functions?

Answer 26

walls - a lot of muscle because it contracts
valves - elastic because stretches when opens and closes

Question 27

Describe the regulation of heart rate (steps)

Answer 27

SA node -> Av node -> fibrous skeleton -> L&R branches -> Purkinje fibers -> Calcium transduction

Question 28

Sinoatrial node:

Answer 28

1. pacemaker
2. sets up atrial contraction
3. first to respond to ANS
4. fastest rate of depolarization

Question 29

AV node:

Answer 29

1. ventricular contraction
2. bundles of His divided into L&R branches and Purkinje fibers
3. carries impulses over fibrous skeleton using His bundles

Question 30

ANS in terms of heart regulation

Answer 30

• parasympathetic: increase ACH -> bradycardia
• sympathetic: increase NER -> tachycardia