Arterial System

Question 1

Main constituents of a vessel wall

Answer 1

Elastin and Collagen

Question 2

Elastin

Answer 2

Highly deformable with low Young’s module

Question 3

Ratio of Elastin and Collagen

Answer 3

Principal determinant of overall elastic behavior of a vessel.

Question 4

Endothelium

Answer 4

Basement membrane and elastic lamina, where endothelial cells are attached.

Question 5

Arteries diameter

Answer 5

Arterial diameter can vary by 10%

Question 6

Removal of elastin

Answer 6

Removal of elastin = stiffening

Question 7

Removal of collagen

Answer 7

= elastic behavior

Question 8

Systolic pressure

Answer 8

Systolic pressure increases with distance from the heart. Diastolic doesn’t

Question 9

Ejection of blood

Answer 9

Ejection of blood leads to expansion of the aorta to accommodate the ejected volume.

Question 10

Increase in circumference of artery?

Answer 10

Increase in circumference increases tension in the arterial wall which increase the pressure within blood.

Question 11

PWV

Answer 11

Pressure wave propagation speed. Changes depending on the distance from he heart.

Question 12

PWV estimation

Answer 12

The difference in arrival time of the pressure wave at different points in the arterial tree

Question 13

Flow

Answer 13

Determined by Reynolds number

Question 14

Reynolds number

Answer 14

Decreases with distance from the heart.

Question 15

Systolic phase has turbulent flow and the remainder of the arterial circulation is laminar

Question 16

Axial flow

Answer 16

Flow in a long straight pipe will become axial after certain distance

Question 17

Rotation flow

Answer 17

Caused in a curve pipe or branching, also twisting of ventricle during contraction

Question 18

Symmetric velocity profile

Answer 18

Long straight tube

Question 19

Asymmetric velocity profile

Answer 19

vessel is curved or immediately downstream

Question 20

Arterial wall forces

Answer 20

Pressure and Shear Stress

Question 21

Arterial wall

Answer 21

Is able to sense forces and adjust in order to compensate for other forces

Question 22

Cyclic variation in pressure

Answer 22

Leads to variation in a diameter and circumference of the artery, trying to reach equilibrum

Question 23

Murray’s Law

Answer 23

Number of vessels increases with each branching and diameters decrease

Question 24

Arterial system design

Answer 24

Is design so that the heart needs to expend the minimum amount of effort to pump blood.

Question 25

Law of Laplace

Answer 25

Blood pressure is opposed by a tension within the arterial wall

Question 26

Mechanostransduction

Answer 26

Process where mechanical forces are translated to biological behavior and vice versa

Question 27

Steps of mechanostransduction

Answer 27

mechanotransition, sensing, signaling, response.

Question 28

Mechanotransition

Answer 28

Stretching and displacement of the cell

Question 29

Mechanosensing

Answer 29

sensors capable of detecting changes

Question 30

Mechanosignaling

Answer 30

force transmission through the cytoskeleton and release chemicals

Question 31

Mechanoresponse

Answer 31

Response can be immediate or take months