Vascular and Ischaemic Heart Disease Flashcards Preview

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Flashcards in Vascular and Ischaemic Heart Disease Deck (241)
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1

Where do the right and left coronary arteries arise from?

The base of the aorta

2

Where does most coronary venous blood drain into?

The coronary sinus and then into the right atrium

3

What area of the heart becomes deprived of blood supply if the left coronary artery becomes blocked?

Left ventricle

4

Give four special adaptations of coronary circulation?

1. High capillary density
2. High basal blood flow
3. High oxygen extraction (75% compared to 25%)
4. Extra oxygen can only be supplied by increasing coronary blood flow

5

What does decreased PO2 do to the coronary arteries?

Causes vasodilatation

6

What is an intrinisc mechanism of coronary blood flow, and matches flow to demand?

Metabolic hyperaemia

7

What is a potent vasodilator for coronary blood flow (intrinsic mechanism)?

Adenosine from ATP

8

What type of nerves are coronary arterioles supplied by?

Sympathetic vasoconstrictor nerves

9

What are sympathetic vasoconstrictor nerves in coronary arterioles over-ridden by?

Metabolic hyperaemia as a result of increased heart rate and stroke volume

10

What does sympathetic stimulation of the heart result in?

Coronary vasodilatation despite direct vasoconstrictor effect

11

What substances activates beta-2-adrenoceptors, which causes vasodilatation?

Adrenaline

12

What receptors does sympathetic stimulation act on in relation to coronary blood flow?

Alpha receptors

13

What do increased metabolites such as K, PCO2 and H+ do to coronary blood flow?

Increase it

14

What does an increase in adenosine, do to coronary blood flow?

Increases it

15

When does peak left coronary flow occur?

During diastole

16

What does shortening diastole (e.g. very fast heart rate) do to coronary flow?

Decreases it

17

What gives blood supply to the brain?

Internal carotids and vertebral arteries

18

What is very sensitive to hypoxia in the brain?

Grey matter

19

What two arteries form the basilar?

Two vertebral arteries

20

What arteries anastomose to for the circle of Willis?

Basilar and carotid arteries

21

Where do the major cerebral arteries arise from?

The circle of Willis

22

What is caused by an interruption/cut-off of blood supply to a region of the brain?

Stroke

23

What are the two main types of stroke?

1. Haemorrhagic bleeding
2. Ischaemic stroke

24

What type of stroke is described - blood leaks out of artery wall which is damaged?

Haemorrhagic stroke

25

What type of stroke is dewscribed - blood clot forms on atheroma on artery wall or comes from another part of body and gets stuck, blood cannot flow past?

Ischaemic stroke

26

What is autoregulation of cerebral blood flow guard against?

Changes in cerebral blood flow if mean arterial blood pressure changes within a range (60 - 160 mmHg)

27

In relation to autoregulation of cerebral blood flow: what happens to resistance vessels automatically when MABP rises?

Resistance vessels constrict to limit blood flow

28

When does autoregulation fail in relation to MABP falling?

Below 60mmHg

29

What does MABP below 50 mmHg, result in?

Confusion, fainting and brain damage if not quickly corrected

30

What does increased PCO2 do to cerebral vessels?

Causes cerebral vasodilatation