CV: Fine-Tuning Flashcards Preview

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Flashcards in CV: Fine-Tuning Deck (47):
1

How does early systole affect blood flow through the coronary artery and why

Reduces blood flow through the coronary artery as the myocardial cells contract and compress it

2

At What stage of the cardiac cycle does blood enter the coronary arteries

Diastole

3

How does a decreased pO2 effect blood moving through coronary arteries

It will cause vasodilation in the coronary arteries

4

How does a disease causing decreased metabolic rate affect the blood flow through the coronary arteries

Reduces blood flow

5

How will work done by the cardiac myocytes affect blood flow through the coronary arteries

Increased work done will increase blood flow through the coronary arteries

6

How does local metabolic activity of cells in the heart affect blood flow via the coronary arteries

It increases the flow through them as increased metabolic activity of the myocytes means they need more oxygen

7

How does local metabolic activity of cells in the skin affect blood flow to the skin

No effect as blood flow to the skin is controlled by thermoregulation not by metabolic activity of the cells

8

How does local metabolic activity of the cells at the lungs affect blood flow to the lungs

The entire CO of the RV HAS to move through the lungs regardless of local cell metabolic activity (usually blood moving through the lungs exceeds the metabolic capacity of the cells in the lungs)

9

Which wall is thicker the right and left atria

They are both the same size as they have similar workloads

10

Three factors affecting the pressure in the arteries

Length
Blood Viscosity
Radius of the capillaries

11

How does halving the radius affect the pressure

It causes the resistance to increase 90%

12

During isovolumic ventricular contraction, what happens to the pressure in the atria?

The pressure in the atria increases as the mitral and tricuspid valves bulge up into the atria

13

How does a decrease in serum calcium ions affect the force of contraction in the left ventricle

It will decrease as the CONTRACTILITY of the myocytes will decrease

14

How does an increase in serum potassium ions affect the force of contraction in the left ventricle

It will decrease as CONTRACTILITY of the myocytes will decrease

15

If my HR decreased, how would CO be affected

Depends. Could decrease but SV might increase to cancel out the effect:

CO = SV x HR

16

What has a smaller total SA, arterioles or capillaries

arterioles

17

Are purkyne tissues smaller or larger than ventricular myocardial cells and why

They are larger because electrical conduction needs to be rapid in order to reach the cells

18

Why do arterioles offer a much greater resistance to flow than other vessels

Due to a greater pressure drop along their length

19

Does the thick muscular wall of the arterioles affect resistance

No

20

Does a small internal diameter affect arteriolar resistance

No, the aorta has a smaller internal diameter but less resistance

21

How does RV CO affect stroke volume in the LV?

It causes more blood to enter the LV via the pulmonary vein which causes greater pre-load. So SV increases in the LV

22

What does the vasa vasorum supply

Elastic Arteries and Large Veins

23

Where are elastic arteries and muscular arteries found

Elastic is proximal to the heart and these become muscular distally

24

Elastic vs Muscular arteries

Elastic contain collagen and elastin in the tunica media whilst the muscular arteries contain smooth muscle

25

Why do we need elastic arteries

Helps to maintain a constant pressure despite the pulsing nature of blood flow

26

Why do we need muscular arteries

Acts as resistance to flow

27

How can I palpate the apex of the heart

Left 5th intercostal space and left mid-clavicular line

28

At what vertebral level does the heart start at

T4/5

29

What are the intercostal muscles innervated by

T1-T11

30

What is the anterior abdominal wall innervated by

T7 -T11

T12

31

What is the thoracic cavity supplied by

Internal thoracic artery

32

What does the internal thoracic artery bifurcate into

Superior epigastric artery and musculophrenic artery

33

At what vertebral level does the internal thoracic artery bifurcate

6th intercostal space

34

What does the posterior intercostal artery branch off from

Aorta

35

What do the anterior intercostal artery branch off from

Internal thoracic artery or Musculophrenic branch

36

What are venae comitantes

Paired veins accompanying major arteries

37

Why are venae comitantes located so close to arteries

Artery pulsations assist flow of blood through the veins

38

What are four roles of the pericardium

a) Fixes the heart to limit motion
b) Prevents overfilling of the heart
c) Lubrication to reduce friction generated by the heart
d) Protection from infection

39

What nerve innervates the pericardium

Phrenic nerve

40

What is the cephalic vein a branch of

Subclavian vein

41

How does factor VII circulate in the blood

Bound to vWF

42

What would be the consequence of vWF not being bound to factor VIII

it would degrade RAPIDLY

43

What compound causes the release of factor VIII from vWF

Thrombin

44

Where is additional vWF released and why is this needed

Released from the endothelium + needed to form additional links between glycoproteins 1b/X/V and collagen fibrils

45

How does thromboxane A2 cause platelet aggregation

By increasing expression of glycoprotein receptors IIb/IIIa on platelet plasma membrane

46

What also causes an increases of receptor IIb/IIIa expression

ADP

47

What effect does thromboxane A2 have on blood vessels

Vasoconstriction