Lecture 26. Fundamentals of Cardiovascular and Respiratory Physiology Part 1.

Question 1

What is the cardiac cycle ?

Answer 1

The contraction and relaxation of the heart in a rhythmic cycle

Question 2

What is another word for the contraction of the heart ?

Answer 2

Systole

Question 3

What is another word for the relaxation of the heart ?

Answer 3

Diastole

Question 4

What is the flow of blood through the heart known as ?

Answer 4

Unidirectional

Question 5

What is backflow of blood prevented by ?

Answer 5

AV and semilunar valves

Question 6

What makes the lub dub heart sound ?

Answer 6

Valve closure

Question 7

What is the cardiac output ?

Answer 7

Volume of blood pumped by each ventricle each minute

Question 8

What regulates cardiac function ?

Answer 8

Autonomic nervous system

Question 9

What does the parasympathetic division of the autonomic nervous system do to the cardiac function ?

Answer 9

Innervates the SA node which slows the heart rate

Question 10

What does the sympathetic division of the autonomic nervous system do in cardiac function ?

Answer 10

Innervates the SA node which increase heart rate

Question 11

How does exercise effect autonomic nervous system function ?

Answer 11

Decreases parasympathetic activity and increases sympathetic activity

Question 12

What is gas exchange ?

Answer 12

The uptake of oxygen from the environment and the discharge of carbon dioxide to the environment

Question 13

What is boyle’s law ?

Answer 13

At constant temperature, pressure and volume are inversely related

Question 14

What biological process is Boyle’s law a part of ?

Answer 14

Breathing

Question 15

What is spirometry ?

Answer 15

Method of measuring lung function

Question 16

What is the gas composition of air ?

Answer 16

1. 79% nitrogen
2. 21% oxygen
3. Trace amounts of carbon dioxide, helium, argon etc.

Question 17

What do gasses diffuse down ?

Answer 17

Pressure gradients (High pressure to low pressure)

Question 18

What is partial pressure ?

Answer 18

The pressure exerted by a particular gas in a mixture of gases

Question 19

In gas mixtures, what do gases diffuse down ?

Answer 19

Partial pressure gradients (High partial pressure to low partial pressure)

Question 20

How is heart beat initiated by autorhythmic activity ?

Answer 20

1. Signals from SA node spread through atria
2. Signals are delayed at AV node
3. Bundle branches pass signals to heart apex
4. Signals spread throughout ventricle

Question 21

What is heart rate and contractile strength modulated by ?

Answer 21

Autonomic nervous system

Question 22

What is tachycardia ?

Answer 22

Abnormally fast heart rate

Question 23

What is bradycardia ?

Answer 23

Abnormally slow heart rate

Question 24

What is fibrillation ?

Answer 24

Loss of coordination of electrical activity. Can be corrected by defibrillation

Question 25

What does atrial fibrillation result in ?

Answer 25

Weakness

Question 26

What does ventricular fibrillation result in ?

Answer 26

Death in minutes, damage to heart muscle

Question 27

What is haemodynamics ?

Answer 27

How blood moves through the circulation

Question 28

What is the process of gas exchange ?

Answer 28

1. Inhaled air 2. Alveolar spaces 3. Pulmonary veins and systemic arteries 4. Body tissue 5. Pulmonary arteries and systemic veins 6. Exhaled air

Question 29

Where is oxygen not very soluble ?

Answer 29

Plasma

Question 30

Where is haemoglobin present ?

Answer 30

In erythrocytes

Question 31

How many molecules of oxygen can haemoglobin bind ?

Answer 31

4

Question 32

Where does carbon dioxide from respiring cells go ?

Answer 32

1. Diffuses into the blood and is transported in blood plasma bound to haemoglobin 2. Diffuses into erythrocytes and reacts with water to form H2CO3

Question 33

What does CO2 affect ?

Answer 33

Blood pH

Question 34

What is the bohr shift ?

Answer 34

Carbon dioxide produced during cellular respiration lowers blood pH and decreases the affinity of hemoglobin for oxygen

Question 35

Where are the breathing control centers found ?

Answer 35

The medulla oblongata of the brain

Question 36

What is the function of the medulla oblongata ?

Answer 36

Regulates the rate and depth of breathing in response to pH changes in the cerebospinal fluid

Question 37

What is hypoxia ?

Answer 37

Low oxygen levels in the tissues

Question 38

What is the V02max defined as ?

Answer 38

The rate of oxygen usage under maximal aerobic metabolism

Question 39

What is oxygen uptake measured in ?

Answer 39

ml/min or ml/min/kg body weight

Question 40

What does the V02 max rely on ?

Answer 40

Cardiovascular and respiratory performance