Week 3 - Lesson 1 (Part 4)

Question 1

What do red blood cells do in low flow states?

Answer 1

They stick together

Question 2

What happens to the velocity in low flow states?

Answer 2

It increases

Question 3

What kind of interactions occur when clotting mechanisms are stimulated? (2)

Answer 3

1. Platelet aggregation

2. Interactions with plasma proteins occur

Question 4

What does stimulation of clotting mechanisms lead to? (2)

Answer 4

1. Entrapment of red cells

2. Clot formation

Question 5

What does entrapment of red cells and clot formation increase?

Answer 5

Viscosity

Question 6

What is an important factor that influences viscosity?

Answer 6

Temperature

Question 7

What kind of relationship does viscosity and temperature have?

Answer 7

An inverse relationship

Question 8

What is the major regulator of vascular resistance?

Answer 8

Regulation of vessel radius

Question 9

What kind of pressure change is there when you go from the aorta to large arteries?

Answer 9

Very little pressure chance

Question 10

What is the pressure change like from larger arteries to smaller arteries like arterioles?

Answer 10

Larger drop

- 70%

Question 11

What kind of regulation do arterioles have?

Answer 11

They are autoregulatory

Question 12

What does vessel diameter affect?

Answer 12

Peripheral resistance

Question 13

What happens as the diameter of the tube gets smaller? (2)

Answer 13

1. Resistance increases

2. Pressure increases

Question 14

What happens to the pressure when you have a larger volume with the same volume?

Answer 14

Less pressure

Question 15

What happens to the pressure when you have a smaller volume with the same volume?

Answer 15

More pressure

Question 16

What does total vessel length affect?

Answer 16

Peripheral resistance

Question 17

What does increased fatty tissue require?

Answer 17

More blood vessels to service it

- adds to the total vessel length in the body

Question 18

What happens to the resistance and pressure with a longer vessel length?

Answer 18

The greater the resistance and pressure is

Question 19

What kind of relationship do vessel resistance and viscosity have?

Answer 19

Direct

Question 20

What kind of relationship do vessel resistance and the radius to the 4th power (r^4) have?

Answer 20

Inverse

Question 21

What kind of relationship do vessel resistance and length of the vessel have?

Answer 21

Direct

Question 22

What does adjustments in the degree of contraction of the circular muscular walls of the arterioles permit? (2)

Answer 22

1. Regulation of tissue flow

2. Helps to control arterial pressure

Question 23

What 2 factors are peripheral resistance controlled by?

Answer 23

1. Sympathetic nerve innervation
2. Autoregulation
   - vasoconstriction and vasodilation

Question 24

Vasoconstriction

Answer 24

Narrowing of the blood vessel due to contraction of the muscular wall

Question 25

How do you get vasoconstriction?

Answer 25

When the smooth muscle found within the tunica media is stimulated, it contracts, squeezing the walls of the artery and narrowing the vessel

Question 26

What happens to the flow of blood and pressure when an artery constricts? (2)

Answer 26

1. Blood flow = decreases | 2. Pressure within the vessel = rises

Question 27

What does vasoconstriction do?

Answer 27

It is a mechanism your body uses to regulate important functions in the body, such as body temperature and blood pressure

Question 28

Vasodilation

Answer 28

Widening of the blood vessel due to relaxation of the muscular wall

Question 29

What happens to the blood flow and resistance when a vessel dilates? (2)

Answer 29

1. Blood = increases | 2. Resistance = decreases

Question 30

What happens to blood flow when you exercise and why? (2)

Answer 30

1. It increases | 2. Delivers more oxygenated blood to the working muscle

Question 31

At what level does vasodilation occur at?

Answer 31

The arteriole and capillary bed level