Cardio Vascular System

Question 1

Define Myogenic

Answer 1

The capacity of the heart to generate its own impulses

Question 2

Name the order of the pulse through the heart

Answer 2

SAN > Atrial Systole > AVN > Bundle of His > Bundle Branches > Purkinje Fibres > Ventricular Systole

Question 3

What does the sympathetic nervous system do ?

Answer 3

Increase heart rate

Question 4

What does the parasympathetic nervous system do ?

Answer 4

Decrease heart rate

Question 5

What do Chemoreceptors do and how does this affect heart rate ?

Answer 5

Detect the content of carbon dioxide in the blood
↑ CO2 = ↑ Heart Rate

Question 6

What does the Medula Oblongata do ?

Answer 6

It regulates vital processes

Question 7

What do Baroreceptors do and how does this affect heart rate ?

Answer 7

Establish a set point for blood pressure
Any increase or decrease sends a signal to the Medulla Oblongata
↑ Arterial Press = ↓ Heart Rate
↓ Arterial Press = ↑ Heart Rate

Question 8

What do Proprioceptors do and how does this affect heart rate ?

Answer 8

Detect and send information about body movement and position
↑ Movement = ↑ Heart Rate
↓ Movement = ↓ Heart Rate

Question 9

How do hormones affect heart rate ?

Answer 9

Adrenaline – Stress Hormone
Stimulates SAN to increase Heart rate and Strength which causes an increase in Cardiac Output

Question 10

Define stroke volume

Answer 10

Volume of blood pumped out per beat

Question 11

Define cardiac output

Answer 11

Volume of blood pumped out per minute

Question 12

Define ejection fraction

Answer 12

Percentage of blood pumped out by the left ventricle per beat

Question 13

Define venous return

Answer 13

Volume of blood returning to the heart through the veins

Question 14

What is the equation for cardiac output

Answer 14

Cardiac Output = Stroke Volume x Heart Rate

Question 15

What is Sterling’s Law ?

Answer 15

A greater force of contraction means an increase in ejection fraction

Question 16

Define Bradycardia

Answer 16

A resting heart rate of less than 60

Question 17

What are the benefits of aerobic exercise ?

Answer 17

Cardiac hypertrophy
Lower resting heart rate
Larger ventricular cavities
Increased stroke volume and diastolic volume
More oxygen delivered to the muscles
Large increase to Cardiac Output

Question 18

Define steady state

Answer 18

When oxygen demand and supply are equal

Question 19

What happens during cardiovascular drift ?

Answer 19

Progressive decrease in stroke volume and arterial blood pressure
Progressive increase in heart rate to compensate

Question 20

What are the conditions for cardiovascular drift to occur ?

Answer 20

Occurs during prolonged exercise in a warm environment after approximately 10 minutes

Question 21

What causes cardiovascular drift ?

Answer 21

Caused by sweating as a proportion comes from blood plasma supply
Lower plasma volume causes blood to become more viscous

Question 22

How can cardiovascular drift be prevented

Answer 22

Plenty of fluid should be consumed regularly

Question 23

What is the pulmonary circuit ?

Answer 23

Heart > Lung

Question 24

What is the systemic circuit ?

Answer 24

Heart > Body

Question 25

what are the 5 types of blood vessels ?

Answer 25

Arteries Arterioles Capillaries Venules Veins

Question 26

What happens to blood pressure during exercise ?

Answer 26

During exercise systolic pressure increases and diastolic pressure decreases

Question 27

Name the 6 types of venous return

Answer 27

Skeletal muscle pump Respiratory pump Pocket valves Gravity Suction pump Smooth muscle in wall of veins

Question 28

Explain how the skeletal muscle pump works

Answer 28

When muscles contract and relax they change shape therefore pressing on the nearby veins

Question 29

Explain how the respiratory pump works

Answer 29

When muscles contract and relax during breathing in and out, pressure changes occur which compress the nearby veins

Question 30

Explain how pocket valves works

Answer 30

Important blood in veins only flows in one direction

Question 31

Explain how exercise affects which venous return mechanisms are used

Answer 31

Rest - Smooth muscle and valves in veins are enough Exercise - Need skeletal muscle and respiratory pump to aid return Post - Still need to maintain these mechanisms

Question 32

What is the impact of pressure on venous return ?

Answer 32

Linked very closely to systolic pressure When systolic pressure increases, venous return also increases

Question 33

What is Coronary heart disease ?

Answer 33

When the Coronary arteries become blocked or begin to narrow due to a build up of fatty deposits (Atheroma) Atherosclerosis

Question 34

What can CHD be caused by ?

Answer 34

High blood Pressure High cholesterol levels Lack of exercise Smoking

Question 35

What is Angina ?

Answer 35

As coronary arteries become blocked, oxygen cant be delivered to the heart therefore causing pain/discomfort

Question 36

What can CHD lead to ?

Answer 36

If a atheroma breaks off it can cause a blood clot which cuts off the oxygen supply to the heart which therefore causes a heart attack

Question 37

What can high blood pressure increase the risk of ?

Answer 37

Heart attack Heart failure Kidney disease Stroke Dementia

Question 38

What is normal blood pressure ?

Answer 38

Systolic - less than 120 Diastolic - less than 80

Question 39

What are the 2 types of cholesterol ?

Answer 39

LDL (Low density lipoproteins) HDL (High density lipoproteins)

Question 40

What are the characteristics of LDL ?

Answer 40

Transports cholesterol in blood to tissues Classed as 'bad' Linked to increase risk of heart disease

Question 41

What are the characteristics of HDL ?

Answer 41

Transports excess cholesterol in the blood to the liver where it is broken down Classed as 'good' Linked to decrease risk of heart disease

Question 42

What is a stroke ?

Answer 42

When blood supply to the brain is cut off causing damage to brain cells

Question 43

What can a stroke lead to ?

Answer 43

Brain injury Disability Death

Question 44

What are the 2 types of strokes and explain them ?

Answer 44

Ischaemic - When a blood clot stops the blood supply Haemorragic - When a weakened blood vessel supplying the brain bursts

Question 45

What are the symptoms of a stroke ?

Answer 45

Face drooping Arm weakness Speech difficulties

Question 46

What are the 3 ways blood can be transported around the body ?

Answer 46

Plasma Haemoglobin Myoglobin

Question 47

How many molecules are on a fully saturated haemoglobin and when does it occur ?

Answer 47

4 molecules of oxygen Occurs when partial pressure of oxygen is high

Question 48

What is oxyhaemoglobin dissociation ?

Answer 48

The release of oxygen at tissues/skeletal muscles due to lower partial pressure

Question 49

Where is oxygen stored in the muscles ?

Answer 49

In the myoglobin because it has a higher affinity for oxygen

Question 50

What is Bohr shift ?

Answer 50

When muscles require more oxygen, the dissociation occurs more readily, causing the graph to shift to the right

Question 51

Causes of Bohr shift

Answer 51

Increased blood temperature Increased partial pressure of carbon dioxide Lower pH level

Question 52

What is vascular shunting ?

Answer 52

The redistribution of cardiac output around the body

Question 53

Key areas of vascular shunting

Answer 53

Brain Heart Skin

Question 54

What controls the blood pressure and flow ?

Answer 54

The vasomotor centre which is located in the medulla oblongata

Question 55

What happens to blood vessels during exercise ?

Answer 55

Vasodilation - Widening of the lumen Vasoconstriction - Narrowing of the lumen

Question 56

What does sympathetic stimulation do to blood vessels ?

Answer 56

Vasoconstriction Reduced blood flow

Question 57

What are pre-capillary sphincters ?

Answer 57

Tiny rings of muscle at the opening of capillaries

Question 58

Why is blood redistribution important ?

Answer 58

Increased oxygen delivery to active muscles and heart Remove waste products Ensure blood goes to skin to cool down

Question 59

What is A-Vo2 diff ?

Answer 59

The difference in oxygen content between the arteries and veins at the muscle