Week 3 - Lesson 1 (Part 2)

Question 1

What does the sympathetic nervous system do? (2)

Answer 1

1. Increase the rate of cardiac contraction

2. Force of cardiac contraction

Question 2

What does the parasympathetic nervous system do? (2)

Answer 2

1. Reduces the heart rate

2. Force of contraction

Question 3

What do the sympathetic and parasympathetic systems respond to?

Answer 3

Many stimuli

Question 4

What does an increased heart rate yield?

Answer 4

An increased volume of blood to the tissues

Question 5

What is necessary to move fluid from one point to another in a closed system?

Answer 5

Energy gradient

Question 6

How does blood move in the case of the arterial tree?

Answer 6

A pressure gradient

Question 7

How is pressure situated in the heart in order to create a necessary pressure gradient?

Answer 7

The left side has higher pressure and the right side has lower pressure

Question 8

Blood pressure

Answer 8

Force exerted by the blood against the arterial walls when the heart contracts

Question 9

What is blood pressure an important indicator of? (3)

Answer 9

1. Current cardiovascular function
2. Risk indicator of future cardiovascular morbidity
3. Risk indicator of future mortality

Question 10

What do capillary beds consist of? (3)

Answer 10

1. Arterioles
2. Capillaries
3. Venules

Question 11

How much does each heart beat approximately eject from the ventricle to the arterial tree?

Answer 11

70cc

Question 12

Why must a considerable portion of the heart’s output must be stored during systole?

Answer 12

Because the small capillary network is unable to transmit large volumes of blood with each heartbeat
- passed on later during diastole

Question 13

What is oscillatory flow in the arterial tree initiated by?

Answer 13

Each beat of the heart

- which behaves like a flow generator with an ejected pulse

Question 14

How much blood is pumped every 5 minutes approximately?

Answer 14

5L

Question 15

When does pressure build in the heart?

Answer 15

At the beginning of each cardiac contraction as the pressure in the left ventricle rapidly rises

Question 16

What happens when the pressure in the left ventricle increases and it exceeds the pressure in the ascending aorta?

Answer 16

It forces the aortic valve open

Question 17

Why does the mean pressure gradually decrease as it goes through the body?

Answer 17

Because of its loss in total fluid energy

Question 18

What happens when the mean pressure decreases?

Answer 18

Systolic pressure begins to increase again

Question 19

What is the wave propagation phenomenon due to?

Answer 19

Increasing stiffness of the vessel walls toward the periphery and the reflected waves which are enhanced by increasing peripheral resistance

Question 20

What kind of arterial reservoir is there in the circulatory system? (2)

Answer 20

1. High pressure

2. High energy

Question 21

What kind of venous reservoir is there in the circulatory system? (2)

Answer 21

1. Low pressure

2. Low energy

Question 22

What do the elastic walls of the conducting arteries do?

Answer 22

They store excess volume by stretching during systole and relaxing during diastole

Question 23

Where is energy stored during diastole?

Answer 23

In the stretched elastic walls of the arteries

Question 24

What is the energy stored in the stretched elastic walls of the arteries during diastole used for?

Answer 24

To propel blood forward through the peripheral resistance vessels
- therefore flow is constant throughout the cardiac cycle

Question 25

When is the blood pressure highest?

Answer 25

During ventricular systole

- contraction

Question 26

When is blood pressure the lowest?

Answer 26

During ventricular diastole

- filling

Question 27

What is considered a normal blood pressure reading?

Answer 27

120/80

Question 28

Where is systolic pressure the highest?

Answer 28

In the heart

Question 29

Where is systolic pressure the lowest?

Answer 29

As it moves to the periphery and enters into the venous system

Question 30

What is the aortic pressure?

Answer 30

110mmHg

Question 31

What is the vena cave pressure?

Answer 31

4mmHg