The heart

Question 1

What is the SA node?

Answer 1

This is the pacemaker potential of the heart

Question 2

What is the P wave?

Answer 2

This is where atrial depolarisation occurs

Question 3

What is atrial depolarisation?

Answer 3

This is where the Na+ gated channels are opened to allow the influx of Na+ ions to depolarise the membrane (making it less negative). Then membrane is then depolarised from -90mV to +30mV, allowing for Ca2+ influx to occur, further depolarising the membrane to allow cardiac contraction

Question 4

What is the QRS complex?

Answer 4

This where the ventricles are depolarised –> ventricular contraction. Here Atrial repolarisation occurs as well

Question 5

What is the T wave?

Answer 5

The T wave is ventricular repolarisation

Question 6

What is a semilunar valve and where are these found?

Answer 6

A semilunar valve is found in the Pulmonary trunk and the Aorta. It prevents back flow of blood back into the ventricles, to allow the blood to continue in the pulmonary and systemic circuits.

Question 7

What is the atrioventricular valve?

Answer 7

This is the valve located between the atria and ventricles. This is to prevent the backflow of blood back into the atria during ventricular contraction

Question 8

What is the atrioventricular valve referred to on the left side of the heart?

Answer 8

Bicuspid valve

Question 9

What is the atrioventricular valve referred to on the right side of the heart?

Answer 9

Tricuspid valve

Question 10

Is the ventricle wall thicker on the right or left side of the heart?

Answer 10

The left side of the heart due to the increased strength needed to exert a high pressure to pump blood into the systemic circuit

Question 11

What feeds the heart?

Answer 11

The coronary arteries feed the heart

Question 12

Where is the superior vena cava located

Answer 12

At the right atrium, the superior vena cava is located which returns the blood from the upper body

Question 13

Where is the inferior vena cava located

Answer 13

The Inferior vena cava is located to the right of the aorta and brings the blood from the lower part of the body back to the heart

Question 14

What allows blood to flow?

Answer 14

A pressure gradient

Question 15

What is the pressure gradient?

Answer 15

It is the difference in pressure from high - low

Question 16

What is blood pressure measured in?

Answer 16

mmHg

Question 17

What is the equation for flow?

Answer 17

Flow= change in pressure/resistance

Question 18

What happens if you increase the diameter in a blood vessel?

Answer 18

Vasodilation = less resistance and greater flow

Question 19

What happens if you decrease the diameter in a blood vessel?

Answer 19

Vasocontriction =more resistance with blood flow against the blood vessel wall and therefore less flow

Question 20

What is EDV?

Answer 20

End Diastolic Volume, which is the volume of blood after the heart has filled up

Question 21

What is systole referred to as

Answer 21

contraction, blood being ejected from the heart

Question 22

What is diastole referred to as

Answer 22

relaxation, the heart filling with blood

Question 23

What is the standard blood pressure?

Answer 23

120/80mmHg

Question 24

What happens if a backflow of blood occurs in the left atrium from the left ventricle?

Answer 24

Pulmonary edema due to the pulmonary veins returning blood back to the heart, causing a build up of blood in the left atrium and therefore pressure due to the heart not working properly

Question 25

What is the left atrioventricular valve also known as?

Answer 25

Mitral valve

Question 26

What causes Calcium release from the Sarcoplasmic reticulum?

Answer 26

An action potential that causes depolarisation of the membrane allowing for the Calcium to be released from the S.R to initiate muscle contraction.