Heart

Question 1

Bundle of HIS

Answer 1

Two branches of the conduction system of the heart that run down the entire length of the septum

Question 2

AVN (atrioventricular node)

Answer 2

A mass of conducting cells located in the right atrial wall which delays transmission of the cardiac impulse and then passes it down the septum

Question 3

SAN (sinoatrial node)

Answer 3

Mass of specialised cells found in the right atrium responsible for emitting the cardiac impulse. Also known as the pacemaker of the heart

Question 4

Purkinje fibres

Answer 4

Specialised cardiac tissue which causes ventricles to contract as it passes the cardiac impulse throughout the myocardium

Question 5

Sympathetic nervous system

Answer 5

Part of the autonomic nervous system that speeds up heart rate

Question 6

Parasympathetic nervous system

Answer 6

Part of the autonomic nervous system that decreases heart rate

Question 7

Medulla oblongata

Answer 7

Part of the brain that regulates process that keep us alive

Question 8

Chemoreceptors

Answer 8

Structures in the carotid arteries that detect an increase in carbon dioxide (detect blood pH)

Question 9

Baroreceptors

Answer 9

Special sensors in tissues in the aortic arch, carotid sins, heart and pulmonary vessels that respond to changes in blood pressure. ONLY ONE WHICH DECREASES HEART RATE

Question 10

Proprioreceptors

Answer 10

Detect changes in muscle movement

Question 11

Mechanoreceptors

Answer 11

Detect muscle contraction

Question 12

Ejection fraction

Answer 12

Percentage of blood pumped out by the left ventricle per beat

Question 13

Myogenic

Answer 13

The capacity of the heart to generate its own impulses and its own heart rate at rest

Question 14

What is the cardiac impulse journey?

Answer 14

1) beat starts with an electrical signal in the sinoatrial node
2) electrical impulse spreads through walls of atria, causing themto contract + force blood into ventricles
3) impulse passes through atrioventricular node which delays transmission to enable to atria to fully contract before ventricular systole begins
4) electrical impulse passes down the bundle of HIS
5) bundle of HIS branch into purkinje fibres -> cause ventricles to contract

Question 15

What is atrial diastole?

Answer 15

Relaxation of the atria meaning the atria fill with blood

Question 16

What happens to valves in atrial diastole?

Answer 16

Atrioventricular valves are closed
Semi-lunar valves are open

Question 17

What is ventricular diastole?

Answer 17

Rising pressure in the atria causes the AV valves to open and the ventricles fill with blood

Question 18

What happens to valves during ventricular diastole?

Answer 18

Atrioventricular valves are open
Semi-lunar valves are closed

Question 19

What is atrial systole?

Answer 19

The atria contract due to the cardiac impulse from SA node. This causes blood to go into ventricles

Question 20

What happens to valves during atrial systole?

Answer 20

Atrioventricular valves are open
Semi-lunar valves are closed

Question 21

What is ventricular systole?

Answer 21

Ventricles contract increasing pressure in the ventricles and forcing blood into the aorta and pulmonary artery

Question 22

What happens to valves during ventricular systole?

Answer 22

Atrioventricular valves are closed
Semi-lunar valves are open