Physiology

Question 1

What are the functions of the cardiovascular system

Answer 1

• Bulk flow system of oxygen carbon dioxicle, nutrients, metabolites, hormones and heat

Question 2

What is the significance of vascular beds being arranged in parallel or series

Answer 2

• so output can be equal and tissues yet oxygenated blood it allows redirection of blood

Question 3

Significance of pressure in the CVS

Question 4

Significance of resistance in the CVS

Question 5

Significance of capacitance in the CVS

Answer 5

Control fractional distribution of blood

Question 6

Function of elastic arteries

Answer 6

• Aorta prevent arterial pressure from going too high by stretching

Question 7

Function of muscular arteries

Answer 7

• Arteries, low resistance conduit, thick elastic wall

Question 8

Function of resistance vessels

Answer 8

• Arteries: narrow lumen, control resistance and therefore flow

Question 9

Function of capacitance vessels

Question 10

Valves and locations

Question 11

Direction of blood flow in the heart

Answer 11

Body → Superior vena cava / inferior vena cava → right atrium →
Tricuspid valve → right ventricle → pulmonary value → pulmonary trunk artery → lungs

Lungs → pulmonary vein → mitral valve → right ventricle → aortic valve → aorta → body

Question 12

Sequence of events occurring during excitation-contraction coupling in cardiac muscle

Answer 12

1. Acetylcholine released from the axon terminal binds to receptors on sarcolemma
2. Action potential travels down t-tubule
3. Sacrcoplasmic rectilium releases calcium min response to change in voltage
4. Calcium binds to trooping, cross-bridges form between actin and myosin

Question 13

What is tetanus and what kind of muscle can exhibit it

Answer 13

• Skeletal muscle I sustained muscle contraction, motor , nerve innovates skeleton muscle emits action potential at a high rate

Question 14

Non - pacemaker action potential stages

Answer 14

1. Initial depolarisation - increase Na
2. Plateau - increase Ca (ltype) and decrease K
3. Repolarisation - decrease Ca and increase K
4. Resting membrane potential - high resting K

Question 15

Pacemaker potential stages

Answer 15

• If channels open
• some ca channels open + if closes
• lots of Ca channels open
• Ca channels close + K channels open
• K channels close
• if channels open

Question 16

What initiates electrical activity in the heart

Answer 16

• senatorial node

Question 17

How is electrical activity carried around the heart?

Answer 17

SA node → AV node→ bundle of his → left + right bundle of his branches → purkinje fibres

Question 18

What is the first wave on ECG and what causes this?

Answer 18

• P wave: atrial depolarisation

Question 19

What is the peak on the ECG and what causes this?

Answer 19

• QRs complex ventricular depolarisation

Question 20

What is the 2nd wave on ECG and what causes this?

Answer 20

• T wave ventricular repolarisation

Question 21

What is the PR interval and what is the normal range for this?

Answer 21

• PR interval 0.12 - 0.2s

Question 22

What does the duration of the QRS complex correspond to

Answer 22

TimeFor ventricle to depolarise 0.08s 3 small boxes

Question 23

What does the QT interval correspond to and what is the normal range for this?

Answer 23

Time for ventricle to deplane and repolarise 0.42s

Question 24

What is meant by stemi

Answer 24

High ST interval for myocardial infarction

Question 25

What is meant by non-stemi

Answer 25

Non- ST elevation in myocardial infarction

Question 26

Sinus tachycardia features

Answer 26

- P waves slightly not present faster rate

Question 27

Sinus brachycardia features

Question 28

Normal sinus rhythm

Question 29

Steps of the cardiac cycle

Question 30

Label pressure volume loop in question jotter

Answer 30

Boop

Question 31

What causes the first to 4th heart sounds

Question 32

Effect of sympathetic system on heart rate

Answer 32

- Release nor adrenaline paired with circulating adrenaline act on B1 receptors on SA mode and increase heart rate

Question 33

Explain the effects of the parasympathetic system on heart rate.

Answer 33

- Vagus nerves release acetylcholine which act on muscamic receptors on SA node, decreases slope of pacemaker potential and decrease heart rate

Question 34

Explain the effects of the sympathetic system on stroke volume

Question 35

Explain the effects of the parasympathetic system on stroke volume

Question 36

Explain the effects of preload and afterload on stroke volume

Answer 36

Preload: increase venues return, EDV and there for stroke volume Afterload: load that muscle tries to contract, if TPR (total peripheral resistance) increases stroke volume will go down

Question 37

Describe the importance of these factors in the control of cardiac output

Question 38

Define systolic pressure

Question 39

Define diastolic pressure

Question 40

Define pulse pressure

Question 41

Explain the origin of the korotkoff sounds and their use

Question 42

Illustrate the changes in the aortic pressure wave as it passes through the vascular tree

Question 43

Illustrate the changes in blood velocity and total crossectional area of the vessels throughout the vasculature

Question 44

Indicate the factors affecting pressure & flow in veins

Question 45

Describe the mechanisms that prevent blood clotting in vessels

Question 46

Identify the processes involved in transport between capillaries and tissues

Question 47

Explain the significance of the blood-brain barrier.

Question 48

Explain the significance of Starling forces and the lymphatic system in relation to oedema

Question 49

Justify the importance of Poiseuille’s Law in relation to the control of resistance and blood flow

Question 50

Define active hyperaemia

Question 51

Define pressure autoregulation

Question 52

Define reactive hyperaemia

Question 53

Explain the basis of the injury response

Question 54

Identify various neural

Question 55

Identify hormonal

Question 56

Identity local factors affecting arteriolar tone

Question 57

Describe the dominant factors controlling blood flow in cardiac beds

Question 58

Describe the dominant factors controlling blood flow in cerebral beds

Question 59

Describe the dominant factors controlling blood flow in pulmonary beds

Question 60

Describe the dominant factors controlling blood flow in renal vascular beds