Heart

Question 1

What does haemoglobin do?

Answer 1

Transports oxygen around the body

Question 2

What is haemoglobin made up of?

Answer 2

4 polypeptide chains.
Quaternary structure.
4 haem groups.
4 oxygen Binding sites

Question 3

How does haemoglobin bind?

Answer 3

With positive cooperativity.
If one binds, others are more likely to bind due to tertiary changes.

Question 4

Veins

Answer 4

Thin mucle layer
Thin elastic layer
Thin walls
Valves
Low pressure

Question 5

Capillaries

Answer 5

No muscle or elastic layer
One cell thick walls for a short diffusion pathway

Question 6

Arteries

Answer 6

Thicker muscle layer for constriction and dilation to control blood volume.
Thicker elastic layer.
Thicker walls due to high pressure

Question 7

Arterioles

Answer 7

Thicker muscle layer than arteries. To restrict blood flow to the capillaries.
Thinner elastic layer than arteries.

Question 8

How to calculate cardiac output?

Answer 8

Heart rate x stroke volume

Question 9

Atrial systole

Answer 9

Atria contracts. Pressure increases. Pressure in atria is above that of the ventricle. Valve opens

Question 10

Ventricular systole

Answer 10

Ventricles contract. Pressure increases. Pressure in ventricle is above pressure in the atria. Valve closes. Pressure then rises higher then aorta. Semi lunar valve opens

Question 11

Diastole

Answer 11

Ventricles and atria relax. Pressure drops. Semi lunar valve closes.

Question 12

What are valves useful for?

Answer 12

Prevent backflow of blood

Question 13

When do valves open?

Answer 13

When pressure behind is greater than in front

Question 14

What valve is between the right atrium and ventricle?

Answer 14

Tricuspid

Question 15

Which valve is between the left atrium and ventricle?

Answer 15

Bicuspid

Question 16

What are the other 2 valves between the ventricles and aorta/ pulmonary artery?

Answer 16

Pulmonary valve
Aortic valve

Question 17

What is the septum?

Answer 17

It separated the left and right sides of the heart. Prevents blood from mixing and maintains oxygen concentration.

Question 18

Why is the heart myogenic?

Answer 18

It contracts and relaxes without any hormonal or nervous stimulation. Does not fatigue

Question 19

Tissue fluid

Answer 19

High hydrostatic pressure at arteriole end of capillary. Water and molecules leave through pores.
Pressure and water potential lowest at venule end. Water is reabsorbed via osmosis near the end.

Question 20

How does tissue fluid rejoin the circulatory system?

Answer 20

Via the lymph vessel

Question 21

Right side of the heart

Answer 21

Deoxygenated
Vena cava.
Right atrium.
Tricuspid valve.
Right ventricle.
Pulmonary valve.
Pulmonary artery

Question 22

Left side of the heart

Answer 22

Oxygenated blood
Pulmonary vein.
Left atrium
Bicuspid valve.
Left ventricle.
Aortic valve.
Aorta.

Question 23

Which arteries provide the heart with oxygenated blood?

Answer 23

Coronary arteries.

Question 24

What is atherosclerosis?

Answer 24

Hardening of the arteries caused by a build up of fatty plaque. Triggered by damage from high blood pressure, smoking, etc. Narrows the lumen and reduces elasticity leading to CVD.

Question 25

How to calculate heart rate?

Answer 25

Look at the R-R interval and do 60/time it takes to do one beat.

Question 26

How to calculate systolic delay?

Answer 26

Look at the P-R interval. Count the squares x 0.04

Question 27

How to calculate stroke volume?

Answer 27

EDV (end diastolic volume) - ESV (end systolic volume)

Question 28

What is tachycardia on a graph?

Answer 28

A fast heart rate usually around 100bpm. Seen as close together beats.

Question 29

What is bradycardia on a graph?

Answer 29

A slow heart rate usually around 60bpm. Beats are seen far apart.

Question 30

What is an ectopic beat on a graph?

Answer 30

An extra beat out of rhythm that causes the QRS complex to be earlier than it should.

Question 31

What is fibrilation on a graph?

Answer 31

Irregular shaking line where there is no clear P line meaning that contraction is uncoordinated.

Question 32

What does it mean if the P-R interval is too long?

Answer 32

There is a blockage to the AVN

Question 33

What does it mean if the P-R interval is too short?

Answer 33

The impulse is bypassing the AVN

Question 34

What does it mean if the S-T interval is too long?

Answer 34

The individual has a heart attack

Question 35

What does it mean if the S-T interval is too short?

Answer 35

There is oxygen deprivation happening

Question 36

What does it mean if the Q-T interval is too long?

Answer 36

There is an increased risk of arrhythmias

Question 37

What does it mean if the Q-T interval is too short?

Answer 37

There is a high heart rate or an electrolyte imbalance.

Question 38

What is the P-R interval?

Answer 38

The time taken for an impulse to travel from the SAN/atria to the ventricle.

Question 39

What is the S-T segment?

Answer 39

The period between the end of ventricular contraction and the start of recovery

Question 40

What is the Q-T interval?

Answer 40

The total time required for ventricles to depolarise and repolarise.

Question 41

What is the P wave?

Answer 41

When the SAN fires and impulse that leads to atrial systole.

Question 42

What is the QRS complex?

Answer 42

When the impulse travels along the Bundle of His and Purkinje fibres and ventricular depolarisation occurs as contraction of the heart occurs.

Question 43

What is the T wave?

Answer 43

When the ventricular muscle repolarises and diastole occurs.

Question 44

What is thrombosis?

Answer 44

A blood clot that is caused by platelets and fibrin to travel to the damaged artery. The clot blocks blood flow.

Question 45

What is an aneurysm?

Answer 45

Plaque in the atheroma weakens the artery wall which causes the artery to push the inner layer through the elastic layer causing a rupture and internal bleeding.

Question 46

How is an atheroma formed?

Answer 46

High blood pressure damages the endothelium. This attracts white blood cells and LDL cholesterol from the blood. These clump together to form fatty strokes that build up in the artery over time. This hardens to form a fibrous plaque that restricts blood flow.