1.1 Cardiovascular System

Question 1

Structure of the heart

Answer 1

Deoxygenated blood enters the heart through through the pulmonary artery. It passes through the right atrium into the fright ventricle where the vena cava carries the blood out of the heart to the lungs to pick up oxygen. The now oxygenated blood the returns to the heart through the pulmonary vein, through the left atrium and left ventricle where it is sent to the rest of the body.

Question 2

What are the 3 main blood vessels and their role in the body?

Answer 2

Vein- transports ———- blood into the heart

Artery- transports ——— blood away from the heart

Capillary

Question 3

Myogenic

Answer 3

The capacity of the heart to generate its own impulses

Question 4

Sinoatrial Node

Answer 4

A small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat (more commonly called the pacemaker)

Question 5

Atrioventricular Node

Answer 5

The node relays the impulse between the upper and lower sections of the heart

Question 6

Systole

Answer 6

When the heart contracts

Question 7

Bundle of His

Answer 7

A collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles

Question 8

Purkinje Fibres

Answer 8

Muscle fibres that conduct impulses in the walls of the ventricles

Question 9

Sympathetic system

Answer 9

A part of the autonomic nervous system that decreases heart rate

Question 10

Parasympathetic system

Answer 10

A part of the autonomic nervous system that decreases heart rate

Question 11

Medulla Oblongata

Answer 11

The most important part of the brain as it regulates processes that keep us alive such as breathing and heart rate

Question 12

Chemoreceptors

Answer 12

But structures in the carotid artery and aortic arch that detect changes in blood acidity caused by an increase or decrease in the contraction of carbon dioxide

Question 13

Baroreceptors

Answer 13

Special sensors in tissues in the aortic arch, carotid sinus and heart and pulmonary vessels that respond to changes in blood pressure to either increase or decrease heart rate

Question 14

Proprioreceptors

Answer 14

Sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement

Question 15

Adrenaline

Answer 15

Stress hormone released by sympathetic nerves and cardiac nerve during exercise which causes increase in heart rate

Question 16

Stroke volume

Answer 16

Volume of bloody pumped out by the heart ventricles in each contraction (ml)

Question 17

Diastole phase

Answer 17

When the heart relaxes to fill with blood

Question 18

Ejection fraction

Answer 18

Percentage of blood pumped out by the left ventricle per beat

Question 19

Cardiac output

Answer 19

The volume of blood pumped out by the heart ventricles per minute

Question 20

Cardiac hypertrophy

Answer 20

Thickening of the muscular wall of the heart so it becomes bigger and stronger; also can mean a larger ventricular cavity

Question 21

Bradycardia

Answer 21

A decrease in resting heart rate to below 60 bpm

Question 22

The cardiac conduction system

Answer 22

Heart generates its own electrical nerve impulses, myogenic. This impulse starts in sinoatrial node. Then passed onto the atrioventricular node. Acts as a distributor and passes action potential to the bundle of His which with the Purkinje fibres spread the impulse through the ventricles

Question 23

Diastole

Answer 23

Relaxation phase of the cardiac cycle

Question 24

The relationship between SV, CO and HR

Answer 24

Stroke volume * heart rate= cardiac output

Question 25

Explain how the chemoreceptors cause an increase in breathing rate

Answer 25

Detected by chemoreceptors in the carotid arteries/aortic arch. Sends impulses to respiratory control centre in medulla. Sends impulses to respiratory muscle via the phrenic nerve/sympathetic system. Increase in rate of contraction of diaphragm and external intercostal muscles therefore breathing rate increases