CV: Fine-Tuning Flashcards

1
Q

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

A

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

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2
Q

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

A

Diastole

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3
Q

How does a decreased pO2 effect blood moving through coronary arteries

A

It will cause vasodilation in the coronary arteries

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4
Q

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

A

Reduces blood flow

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5
Q

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

A

Increased work done will increase blood flow through the coronary arteries

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6
Q

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

A

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

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7
Q

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

A

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

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8
Q

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

A

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)

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9
Q

Which wall is thicker the right and left atria

A

They are both the same size as they have similar workloads

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10
Q

Three factors affecting the pressure in the arteries

A

Length
Blood Viscosity
Radius of the capillaries

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11
Q

How does halving the radius affect the pressure

A

It causes the resistance to increase 90%

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12
Q

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

A

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

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13
Q

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

A

It will decrease as the CONTRACTILITY of the myocytes will decrease

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14
Q

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

A

It will decrease as CONTRACTILITY of the myocytes will decrease

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15
Q

If my HR decreased, how would CO be affected

A

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

CO = SV x HR

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16
Q

What has a smaller total SA, arterioles or capillaries

A

arterioles

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17
Q

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

A

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

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18
Q

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

A

Due to a greater pressure drop along their length

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19
Q

Does the thick muscular wall of the arterioles affect resistance

20
Q

Does a small internal diameter affect arteriolar resistance

A

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

21
Q

How does RV CO affect stroke volume in the LV?

A

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

22
Q

What does the vasa vasorum supply

A

Elastic Arteries and Large Veins

23
Q

Where are elastic arteries and muscular arteries found

A

Elastic is proximal to the heart and these become muscular distally

24
Q

Elastic vs Muscular arteries

A

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