cardiology physiology Flashcards

1
Q

what will inhibition of COX 2 cause

A

platelet aggregation. allowing the reaction to happen causes physiological inhibition of aggregation

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2
Q

what are the precursor to RBCs and when will they be raised?

A

reticulocytes, raised in normocytic anaemias (lower in the other two) or haemolytic anaemia and in bleeding.

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3
Q

what will cause peripheral arteriodilation

A

CO2, hypoxia, adenosine, H+, ANP

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4
Q

what surrounds capillaries

A

pericytes

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5
Q

what do baroreceptors do?

A

quickly increase angiotensin levels when not stimulated, when stretched, they decrease angiotensin levels

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6
Q

list the stages in the cardiac cycle

A

diastole (atrial filling then ventricular contraction then diastase); atrial contraction; closing of mitral and tricuspid valves; isovolumic contraction; rapid then reduced ejection; closing of semilunar valves (2nd heart sound)

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7
Q

describe the route of blood in the foetal circulation

A

from placenta>umbilical vein>ductus venosus (some to liver)>right atrium>foramen ovale>left atrium>left ventricle>aorta. If in right atrium>pulmonary artery>ductus arteriosus>aorta.

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8
Q

what day does the heart start beating

A

day 22

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9
Q

describe the cardiac action potential

A

0 inward Na depolarises
1 initial repolarisation K out and Na stops going in
2 plateau, K out and Ca in
3 repolarisation lots of K out
4 resting potential, K slowly goes back in

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10
Q

what is the PR interval

A

the time it takes for the action potential to reach the AV node

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11
Q

what is the ST segment

A

ventricular depolarisation period

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12
Q

what is the T wave

A

ventricular repolarisation

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13
Q

define pre load

A

end diastolic volume

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14
Q

define afterload

A

the aortic pressure against the left ventricle

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15
Q

what joins myocytes

A

intercalated discs

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16
Q

what is ANP

A

atrial natrietic peptide, excreted mostly by RA to decrease sodium and water by inhibiting renin

17
Q

what are heart muscle cells

A

involuntary striated

18
Q

what does the baroreceptor reflex do?

A

increases CO and causes vasoconstriction in muscles and the GI tract. receptors are in the carotid sinus

19
Q

what does histamine do to blood vessels

A

dilates arteries and contricts veins>oedema

20
Q

which layer of blood vessels contains autonomic nerves that control the smooth muscle?

A

the adventitia

21
Q

what will decreased renal perfusion cause

A

renin release to increase BP by reabsorption, intake and vasoconstriction

22
Q

what happens to the blood that enters the heart in the foetal circulation?

A

goes through the ductus arterioles, which is distal to the brachiocephalic trunk and left carotid/subclavian

23
Q

what kind of structural defect can occur after an MI?

A

VSD

24
Q

what structural abnormalities can lead to Eisenmenger’s syndrome

A

ASD
VSD
patent ductus arteriosus
TOF

25
Q

what makes up tetralogy of fallot?

A

VSD, aorta overriding VSD, pulmonary stenosis and right ventricular hypertrophy

26
Q

what do you need to be careful of before cardiac surgery in someone with a structural defect?

A

Eisenmenger’s, surgery will kill because the defect is RL so it’s relieving the high pressure in the right

27
Q

what is classic of TOF on XR?

A

boot shaped heart

28
Q

how is VSD treated?

A

it may close by itself so treated with diuretics and beta blockers (rate control)

29
Q

what are the normal parameters for heart rate?

A

60-100

30
Q

what happens on inspiration to the heart rate?

A

parasympathetic tone decreases so the heart rate increases

31
Q

what can cause bradycardia?

A

hypothermia, hypothyroidism, cholestatic jaundice, raised ICP, anti-arrythmic drugs, ischaemia or fibrosis of the SAN, neurally mediated syndromes

32
Q

give some causes of heart block

A

infiltration, infection (Chagas’, Lyme, endocarditis), digoxin, beta blockers, SLE, cardiac surgery

33
Q

features of RBBB

A

V1-tall late R waves

I V6-deep S waves

34
Q

what will left postero-inferior hemiblock look like?

A

right axis deviation

35
Q

what is Wolff Parkinson White a type of?

A

AVRT (bundle of Kent)