Final: Part 1

Question 1

Wall Layers of the Vascular System

Answer 1

Intima
Media
Adventitia

Continues with and analogous to heart wall layers

Question 2

Intima

Answer 2

inner

• contract blood
• single layer endothelial cells with thin layer of elastic lamina

Question 3

Media

Answer 3

middle

-smooth muscle

Question 4

Adventitia

Answer 4

outer

-connective tissue

Question 5

Arteries

Answer 5

• carry blood away from heart
• most developed media and adventitia
• most elastic
• greatest pressures
• above level of heart, unidirectional valves
• arterioles similar to arteries but smaller
• precapillary sphincter

Question 6

Veins

Answer 6

• take blood to heart
• largest lumen diameters
• large blood reservoirs
• since veins under very low pressures and return blood adjacent gravity to heart
• –below level of heart-unidirectional valves
• –muscle pump
• –respiratory pump
• venules similar to being, but smaller

Question 7

SBP

Answer 7

higher pressure within vascular system, generated during cardiac systole

Question 8

DBP

Answer 8

lowest pressure within vascular system, generated during cardiac systole

Question 9

Factors that Resistance to blood flow depends on

Answer 9

• Vasocosntriction
• Vasodilation
• Arterioles-resistance vesels- 70-80%

Question 10

Factors affecting BF

Answer 10

• during exercise, BF directed away from viscera towards active skeletal and cardiac muscle
• when high Tb —-> increase BF to skin —> heat dissipation. during sub maximal exercise, increase BF to skin —> allows heat dissipation. From submit to maximal exercise, decrease BF to skin —-> compromise heat dissipation in favor of muscle contraction
• during and after meals, increase BF to GI. I you want food before exercise, competition between GI and muscle for BF. Muscles win

Question 11

Precapillary Sphincter

Answer 11

adjusting smooth muscle tone in vessel walls, especially arterioles at pre capillary sphincter

Question 12

What assists venous return below level of heart

Answer 12

SNS stimulation to veins causes venoconstriction —> increase venous return
-blood in venous channels quickly redistributed to areas needing BF (Frank-Starling)

Question 13

Capillaries

Answer 13

1 cell layer thick

Gas exchange

Question 14

BF distribution

Answer 14

Blood reservoir

BF shifts from rest to submit ex. to max ex.

Question 15

Acute Control in Microvascular Regulation

Answer 15

changes in local concentrations of substances that act as vasodilators or vasoconstrictors

Question 16

Long Term Control in Microvascular Regulation

Answer 16

production of vascular growth factors causes angiongenesis

Question 17

NO in Microvascular Regulation

Answer 17

• stimuli like E/NE or mechanical deformation promotes synthesis and release of NO from vascular endothelium
• strong vasodilator
• basal levels of NO prevent excessive vasoconstriction of kidneys, allowing normal Na+ and H2O secretion. If NO inhibited, hypertension ensues-common cause of hypertension in African Americans
• Nitroglycerine causes NO release
• NO causes angiogenesis

Question 18

Low O2 vs. high O2

Answer 18

• smooth muscle requires O2 to contract. when increase O2 is high, strength of contraction increases sitting associated capillaries
• low O2 causes vasodilation
• O2 extremely potent in controlling coronary vascular tone
• O2 extremely potent inhibitor of angiogenesis

Question 19

Endothelin

Answer 19

• in endothelial cells of all blood vessels
• released when endothelium damaged
• powerful vasoconstriction-prevent excessive blood loss in affected artery

Question 20

Vasomotor Tone

Answer 20

Normally, SNS continuosly transmits frequent impulses to blood vessels to keep them in state of moderate constriction to maintain adequate BP