Human Phys 4.1

Question 1

What are all blood vessels?

Answer 1

Distensible (elastic)

Question 2

What does the elastic nature of arteries allow them to do?

Answer 2

Buffer fluctuations in pressure and pulsatile output to deliver constant non-pulsatile blood flow preventing transmission of excess energy to target organs

Question 3

What will repeated exposure to pulsatile pressure/flow to high flow organs cause?

Answer 3

Micro vascular hypoperfusion and ischemia

Question 4

How much more distensible are veins than arteries?

Answer 4

8x more

Question 5

Why do veins serve as blood reservoirs?

Answer 5

They are much more distensible than arteries (hold 64% of blood volume)

Question 6

Vascular compliance

Answer 6

Volume/pressure

Question 7

Compliance

Answer 7

Total quantity of blood that can be stored in a given portion of the circulation

Question 8

What are more compliant between veins and arteries?

Answer 8

Veins

Question 9

Elastance

Answer 9

Pressure/volume

Question 10

What has higher elastance between veins and arteries?

Answer 10

Arteries

Question 11

Why are IVs given in the veins only?

Answer 11

Because a change in volume does not effect pressure as much

Question 12

Arteries (pressure and volume)

Answer 12

Pressure increases high and volume stays low

Question 13

Veins (pressure and volume)

Answer 13

Volume increases high pressure stays low

Question 14

Stress relaxation

Answer 14

Property or biological tissues that is related to their viscoelastic properties

Question 15

What happens to blood vessels when exposed to increased pressure?

Answer 15

They show delayed stretching allowing pressure to normalize

Question 16

What is a way that vasculature responds to hemorrhage?

Answer 16

Delayed compliance (reverse stress relaxation)

Question 17

What would happen if arterial distensibility was absent (arterial stiffness)?

Answer 17

Blood would only flow during systole and no flow would occur during diastole

Question 18

What are factors affecting pulse pressure?

Answer 18

Increase in SV increases pulse pressure

Increase in Arterial compliance decreases pulse pressure

Question 19

What happens during stiff arteries?

Answer 19

Velocity is higher because there is no wasted energy to expand vessels (but causes no flow during diastole) (poor ventricular filling)

Question 20

What happens between SBP and DBP as we age?

Answer 20

It gets farther apart due to artery stiffness

Question 21

What does increase stiffness result in?

Answer 21

Increased pulse wave velocity (pulse wave velocity is bad)

Question 22

What is the most beneficial exercise for arterial stiffness?

Answer 22

Aerobic exercise

Question 23

Arteriosclerosis

Answer 23

Stiff arteries (low compliance)

Question 24

Aortic stenosis

Answer 24

Diminished blood flow due to narrow openings

Question 25

Patent ductus arteriosus

Answer 25

More than 1/2 of blood pumped into aorta flows backward into the PA causing a significant drop in DBP

Question 26

Aortic regurgitation

Answer 26

Aortic valve does not close and blood flows back into the LV causing pressure to drop close to zero

Question 27

What is damping caused by?

Answer 27

Resistance of blood movement Compliance of vessels

Question 28

Where does most damping occur?

Answer 28

Arterioles (because most resistance and least compliance is found here)

Question 29

What is the first sound?

Answer 29

Systolic BP

Question 30

What is the disappearance of the sound?

Answer 30

Diastolic BP

Question 31

What is the BP equation?

Answer 31

BP=CO x TPR

Question 32

What are the two physical determinants of pulse pressure?

Answer 32

Arterial compliance and the change in arterial volume

Question 33

What are the two physiological determinants of mean arterial pressure?

Answer 33

Cardiac output and total peripheral resistance