VASCULAR: ARTERIAL VASCULATURE

Question 1

Define: tunica intima

Answer 1

• intimate with the lumen of the vessel

endothelium
one cell layer thick
paracrine functions
present throughout vasculature

Question 2

Define: tunica media

Answer 2

variable number of cell layers thick
contains EC matrix, elastin, collagen
contains smooth muscle cells

Question 3

Define: tunica adventitia

Answer 3

site of sympathetic nerves
“vaso vasorum”: describes that some blood vessels are so big, they need their own blood supply; blood vessels for blood vessels
extensive EC matrix

Question 4

Why are capillaries suitable for gas exchange?

Answer 4

Flow through capillaries is slow which is suitable for gas exchange due to velocity being inversely related to CSA

Question 5

Describe velocity in terms of flow and cross sectional area

Answer 5

Velocity = Q/A

Question 6

What determines resistance?

Answer 6

• Poiseuille’s Law
• arrangement of blood vessels

Question 7

How does having the vessels in series vs parallel affect the resistance?

Answer 7

Series: R total = R1 + R2 + R3 ….. (seen in arterioles)

Parallel: 1/ R tot = 1/R1 + 1/R2 + 1/R3… (seen in capillaries)

Question 8

Define: compliance

Answer 8

Compliance = change in vol/ change in pressure: the stretchiness of a volume

High compliance implies high distensibility (i.e. stretchy)
- a large volume change for a given pressure change

High compliance decreases pulsatility of flow
- the vessel wall absorbs the cardiac pulse wave

Question 9

Compliance decreases with ___

Answer 9

age

Question 10

What are 3 affects of reduced compliance

Answer 10

Increased pulsatility
Impairs baroreflex function - contributes to hypertension with aging
Increases systolic pressure and thus afterload