Session 1

Question 1

Why does the heart need a blood supply if the LV is already filled with oxygen?

Answer 1

The cells are too far from the source of oxygen and diffusion only works over very small distance

Question 2

What is infarction?

Answer 2

Death of cells due to insufficient blood supply

Question 3

What is the wall structure of capillaries?

Answer 3

Composed of a single layer of endothelial cells (simple squamous epithelium) surrounded by a basal lamina

Question 4

How do small water soluble molecules pass through capillaries?

Answer 4

Pass through spaces between endothelial cells

Question 5

How do lipid soluble molecules/oxygen pass through capillaries?

Answer 5

Diffuse through the capillary cell wall

Question 6

What are 3 factors affecting diffusion?

Answer 6

Area available for exchange

Diffusion resistance

Concentration gradient

Question 7

What is capillary density?

Answer 7

How many capillaries there are in a certain tissue

Question 8

What is the relationship between a more metabolically active tissue and its capillary density?

Answer 8

More metabolically active tissue will have a higher capillary density so there is more area for diffusion to take place

Question 9

What 3 organs require a high constant flow of blood?

Answer 9

Brain
Heart
Kidneys

Question 10

What happens to the blood flow to the heart during exercise? What happens to blood flow to skeletal muscle during exercise?

Answer 10

It increases

Can be very high

Question 11

When is blood flow to the gut at its highest?

Answer 11

After a meal

Question 12

What is the typical cardiac output for a 70kg man at rest? What can it increase to depending on exercise?

Answer 12

5 litres/minute

25 litres/minute

Question 13

What is the position of the heart in the body? (2)

Answer 13

Sits behind the sternum

Largely in the middle of the chest

Question 14

What is the position of the apex of the heart in the body? (2)

Answer 14

Sits on the left hand side of the body

In the 5th intercostal space

Question 15

What does the heart sit between and within?

Answer 15

Between the lungs

Within the pericardial sac

Question 16

What is the physical relationship between the heart and the diaphragm?

Answer 16

It is attached to the diaphragm at the bottom

Question 17

What are the different layers of the pericardium from the outside inwards?

Answer 17

Fibrous layer
Parietal layer
Pericardial cavity 
Visceral layer
Myocardium
Endocardium

Question 18

What are the properties of the fibrous layer of the pericardium?

Answer 18

Very thick and not elastic (won’t stretch)

Question 19

What is found within the pericardial cavity?

Answer 19

A small amount of lubricating fluid

Question 20

What is cardiac tamponade?

Answer 20

Where excess fluid builds up in the pericardial cavity and compresses the heart as the fibrous layer is not able to stretch

Question 21

What is pericardiocentesis? Why would it be carried out? (2)

Answer 21

Removal of fluid from the pericardial cavity

For testing/relieve compression

Question 22

What is the transverse pericardial sinus? What is the clinical significance of it?

Answer 22

The passage between the aorta and pulmonary artery anteriorly and the superior vena cava posteriorly

The passage allows clamps to be placed around certain vessels when a heat lung bypass is required during surgery

Question 23

What is the position of the right side of the heart in-situ?

Answer 23

Right side forms the inferior part of the heart and sits on the diaphragm

Anterior part is largely right side of the heart

Question 24

Where do the left and right coronary arteries stem from? Where do they rise?

Answer 24

They are the first vessels to stem from the aorta

Arise just above the cusps of the valves

Question 25

Where does the left coronary artery specifically arise? Where does the right coronary artery specifically arise?

Answer 25

In the left aortic sinus In the right aortic sinus

Question 26

Where does the anterior interventricular artery stem from? What is the clinical significance of the anterior interventricular artery? What does the anterior interventricular artery pass and supply?

Answer 26

Left coronary artery Often blocked in someone with an MI Passes down the septum and supplies the septum, apex and right and left ventricles

Question 27

What vessel carries out the main venous drainage of the heart?

Answer 27

The coronary sinus

Question 28

Where does the coronary sinus drain into?

Answer 28

The right atrium

Question 29

What type of arteries are coronary arteries?

Answer 29

End arteries with few anastomoses

Question 30

What can a blocked major coronary artery result in? Why?

Answer 30

MI There is no collateral blood supply to certain parts of the heart resulting in cell death and myocardial infarction

Question 31

Coronary arteries are prone to accumulation of...

Answer 31

Fatty deposits (atheroma)

Question 32

What is the difference between plasma and serum?

Answer 32

Plasma is the fluid found in unclotted blood Serum is the fluid found in clotted blood - plasma minus the clotting factors (fibrinogen)

Question 33

What is peripheral resistance? What happens to peripheral resistance during arterial constriction and dilation?

Answer 33

Resistance of the arteries to blood flow During constriction ---> PR increases During dilation ---> PR decreases

Question 34

What is the cancer of plasma cells called?

Answer 34

Multiple myeloma

Question 35

Multiple myeloma can result in an increase in plasma viscosity and can lead to...

Answer 35

Increased whole blood viscosity and sludging of blood in the peripheries

Question 36

As well as multiple myeloma what else can cause sludging of blood in the peripheries?

Answer 36

Polycythaemia Thrombocythaemia Leukaemia

Question 37

Why is sludging of blood more likely to happen at the peripheries?

Answer 37

There is a lower temperature in these areas, so blood is more likely to set

Question 38

What are 3 examples of acute phase plasma proteins? Changes in these can be used to measure what?

Answer 38

Fibrinogen Complement factors CRP Plasma viscosity

Question 39

Plasma viscosity can be used to measure what? How?

Answer 39

The inflammatory response The acute phase plasma proteins are seen at increased levels during inflammation and changes in these are what allows plasma viscosity to be measured

Question 40

What is the most common way to measure inflammation?

Answer 40

C-reactive protein

Question 41

Fluids move from regions of _____ pressure to regions of _____ pressure

Answer 41

High to low

Question 42

Name two different types of blood flow

Answer 42

Laminar flow | Turbulent flow

Question 43

Describe the laminar flow of blood

Answer 43

Usual flow of blood in streamlines | The velocity of the blood in the centre of the vessel is greater than the blood towards the outer edge

Question 44

Why does blood in the centre of the vessel flow faster in laminar flow?

Answer 44

There is less friction compared to blood that flows towards the outer edge

Question 45

Describe turbulent flow of blood

Answer 45

Blood flowing in all directions and continually mixing within the vessel

Question 46

When does turbulent blood flow occur? (5)

Answer 46

When the rate of blood flow becomes too great (anaemia) When it passes by an obstruction in a vessel (stenosis) When it makes a sharp turn When it passes over a rough surface (atheroma) When there is increased resistance to blood flow

Question 47

Flow is measured in...

Answer 47

Volume per unit time e.g. Litres/min

Question 48

Pressure is measured in...

Answer 48

Psi (pounds per square inch)

Question 49

What does compliant mean in regards to blood vessels?

Answer 49

Volume of blood vessel will change in response to a change in pressure

Question 50

Changes in blood flow give a pulse, the more quickly the flow changes...

Answer 50

The greater the pulse

Question 51

What is a stenosis?

Answer 51

A narrowing

Question 52

In the arterial system anything beyond the stenosis is _____ and anything before the stenosis is _____

Answer 52

Distal Proximal

Question 53

What effect will stenosis have on the flow distally...

Answer 53

It will result in the flow distally decreasing but the velocity increasing (increased kinetic energy of the liquid)

Question 54

The increased velocity of the blood following a stenosis will...

Answer 54

Likely stretch the artery after the stenosis result in an aneurysm

Question 55

Where is it common for one stenosis to be followed by another stenosis?

Answer 55

In the legs

Question 56

What happens if there is one stenosis followed by another?

Answer 56

The flow will stop - pressure is reduced as the blood passes through each stenosis and eventually the flow will stop resulting in 'critical ischaemia' in the legs

Question 57

Why are you less likely to be able to feel/take a pulse in an elderly person?

Answer 57

In elderly people arteries can calcify resulting in vessels that are less compliant

Question 58

What is a thrill?

Answer 58

The vibrations you FEEL when there is a stenosis as a result of the turbulent blood flow

Question 59

What is a bruit?

Answer 59

The turbulent sound you HEAR when you listen with a stethoscope at the point of a stenosis

Question 60

If you hear a turbulent sound across a heart valve it is called a...

Answer 60

Murmur

Question 61

What does a pressure tracing usually measure?

Answer 61

The pressure changes in the descending aorta

Question 62

What is the upwards segment of a pressure tracing called? What is the downwards segment of a pressure tracing called?

Answer 62

Anacrotic limb Dicrotic limb

Question 63

What are the different stages of a pressure tracing?

Answer 63

``` Systolic uptake Peak systolic pressure Systolic decline Dicrotic notch Diastolic runoff End diastolic pressure ```

Question 64

What parts of the pressure tracing indicate systole and which parts indicate diastole?

Answer 64

Systole = from end-diastolic pressure to dicrotic notch Diastole = from dicrotic notch to end-diastolic pressure

Question 65

What does the area under the curve in a pressure tracing equate to?

Answer 65

The mean arterial pressure

Question 66

What does the anacrotic limb show?

Answer 66

The pressure rising as blood is ejected into the descending aorta (systolic uptake) until it reaches a max (peak systolic pressure)

Question 67

What happens after the peak systolic pressure is reached?

Answer 67

The aorta begins to stretch and the left ventricle begins to relax. Pressure in the descending aorta falls (systolic decline)

Question 68

What does the dicrotic notch represent? What happens to the pressure at the dicrotic notch?

Answer 68

The point where the aortic valve snaps shut and systole ends There is a small increase in pressure

Question 69

Where is the lowest pressure seen in a pressure tracing?

Answer 69

At the end of diastole - end-diastolic pressure

Question 70

What is the pulse pressure? What value does it commonly take?

Answer 70

Difference between the peak systolic pressure and end-diastolic pressure 40 mmHg

Question 71

What can the mean arterial pressure be estimated as? What value does it commonly take?

Answer 71

Diastolic pressure + 1/3 of pulse pressure 93 mmHg

Question 72

What value does mean arterial pressure have to fall below for organ perfusion to be impaired?

Answer 72

70 mmHg

Question 73

The pulse pressure is the main determinant of ...

Answer 73

How strong a pulse you feel

Question 74

What can happened to the flow of blood in arteries during diastole?

Answer 74

Retrograde flow can occur especially when the peripheral resistance is high

Question 75

What is meant by the volume of the pulse?

Answer 75

The strength of the pulse

Question 76

What 2 factors affect the volume of the pulse?

Answer 76

The force with which the left ventricle is able to eject blood into the arterial system The pulse pressure

Question 77

What is a bounding pulse?

Answer 77

A strong pulse

Question 78

What effect does bradycardia have on pulse pressure and the pulse?

Answer 78

Widens pulse pressure and leads to a bounding pulse

Question 79

Why does bradycardia result in an increased pulse pressure?

Answer 79

Slow heart rate means diastole has longer to occur so increased pulse pressure and bounding pulse

Question 80

What is another term for a weak pulse?

Answer 80

A thready pulse

Question 81

What can result in a reduced pulse volume (thready pulse)?

Answer 81

LV failure Aortic Valve Stenosis Hypovolaemia

Question 82

What are two causes of hypovolaemia?

Answer 82

Severe dehydration Bleeding

Question 83

Vasodilation will have what effect on peripheral resistance?

Answer 83

Means a low peripheral resistance

Question 84

What can cause vasodilation? (3)

Answer 84

Hot bath Exercise Pregnancy

Question 85

What effect does low peripheral resistance have on the diastolic pressure, the pulse pressure and the pulse?

Answer 85

Lower diastolic pressure Increased pulse pressure Bounding pulse

Question 86

What are the normal systolic and diastolic blood pressures?

Answer 86

120 mmHg 80 mmHg

Question 87

When taking a blood pressure measurement what 2 factors are important in producing an accurate reading?

Answer 87

Taking more than 1 reading and then calculating an average Using the right size blood pressure cuff

Question 88

How big must the blood pressure cuff be in relation to the patient?

Answer 88

Must go around at least 80% of the arm circumference

Question 89

What effect will a blood pressure cuff that is too small have on the blood pressure reading?

Answer 89

You will get a falsely high reading