Cardiovascular system

Question 1

cellular portion of body =

Answer 1

buffy coat (leukocytes, thrombocytes)
+
haematocrit (erythrocytes)

Question 2

cardiac output equation

Answer 2

cardiac output (Q) = mean arterial pressure (ΔP)/ total peripheral resistance (R)

cardiac output = heart rate x stroke volume

cardiac output = venous return

Question 3

cardiac output (CO)

Answer 3

amount of blood pumped by the heart per minute (L/min)

Question 4

heart rate (HR)

Answer 4

number of beats per minute

Question 5

stroke volume (SV)

Answer 5

amount of blood pumped out of heart per beat

Question 6

venous return (VR)

Answer 6

rate of blood flow back to right side of heart

Question 7

ejection fraction (EF)

Answer 7

fraction of blood ejected from ventricle of the heart with each heart beat

Question 8

end-diastolic volume (EDV)

Answer 8

volume of blood in right and left ventricle at end load (preload) or filling in (diastole)
or amount of blood in ventricles just before systole

Question 9

end-systolic volume (ESV)

Answer 9

volume of blood in ventricle at end of systole and beginning of filling (diastole)
(lowest volume of blood in ventricle at any point in cardiac cycle)

Question 10

EF, SV and EDV equation

Answer 10

EF = SV/ EDV

Question 11

SV, EDV and ESV equation

Answer 11

SV = EDV - ESV

Question 12

parasympathetic innervation of the heart

Answer 12

left and right vagus nerve to pacemakers
parasympathetic decreases heart rate and strength of muscle contraction
acetylcholine increases K+ permeability (repolarisation)

Question 13

sympathetic innervation of the heart

Answer 13

diffuse from ganglia chain along spinal cord into myocardium
sympathetic increases heart rate and strength of muscle contraction
noradrenaline increases Na+ and Ca2+ permeability (depolarisation)

Question 14

ECG

Answer 14

P wave - atrial depolarisation (frequency is atrial rate)
PR segment - continuation of atrial depolarisation
QRS complex - ventricular depolarisation (frequency is ventricular rate)
ST segment - between ventricular depolarisation and repolarisation
T wave - ventricular repolarisation (flat line after T wave is ventricular diastole)
U wave - papillary muscle and Purkinje fibres repolarisation

Question 15

bradycardia
tachycardia
arrhythmia 
ectopic 
asystole

Answer 15

slow heart rate
fast heart rate 
normal increase in heart during inspiration
earlier atrial/ ventricular heart beat 
flat line/ no electrical activity

Question 16

heart failure

Answer 16

heart unable to fill with enough blood or unable to pump blood around body with enough force

Question 17

causes of heart failure

Answer 17

direct (internal) - heart muscle/ valves

indirect (external) - circulation/ peripheral blood vessels (increased vascular resistance hypertension)

Question 18

two types of hyperaemia

Answer 18

increase of blood flow in tissue/ organ

active hyperaemia - due to increased metabolic activity of organ/ tissue

reactive hyperaemia - following a period of ischaemia (blockage)

Question 19

atheroma

Answer 19

degeneration of artery walls caused by accumulation of fatty deposits and scar tissue leading to restriction of circulation

Question 20

atherosclerosis

Answer 20

hardening of arteries due to plaque formation

Question 21

inotropic effects

Answer 21

alters muscular contraction by Ca2+

parasympathetic ⬇
sympathetic ⬆

Question 22

chronotropic effects

Answer 22

alters heart rate by affecting electrical conducting system

parasympathetic ⬇
sympathetic ⬆

Question 23

dromotopic effects

Answer 23

alters rate of electrical impulses/ conduction velocity by affecting conduction speed in AV node

parasympathetic ⬇
sympathetic ⬆

Question 24

3 layers of blood vessels

Answer 24

tunica intima - endothelium
tunica media
tunica externa

Question 25

triple response of Lewis to scratched skin

Answer 25

red reaction - red line, local vasodilation, cytokine, histamine
flare - red spreads
wheal - localised oedema (swelling)

Question 26

vasodilation factors

Answer 26

histamine (released by basophils and mast cells)

NO inhibits Ca2+ release

Question 27

vasoconstriction factors

Answer 27

thromboxane

angiotensin II

Question 28

Korotkov sounds

Answer 28

when obstruction results in compressed artery so turbulent flow
(laminar flow if no obstruction)

Question 29

control of arterial pressure

Answer 29

baroreceptors in carotid body, aortic bod, wall of arteries of neck and thorax
stretched –sensory afferent neurons–> medulla –motor efferent neurons (para/sympathetic)–> (heart??)

Question 30

short term mechanisms to regulate bp (3)

Answer 30

baroreceptor reflexes - peripheral resistance, HR, SV
chemoreceptor reflexes - hypoxia, CO2 excess, low pH blood
central nervous system ischaemic response - decrease in blood flow of brain)

Question 31

long term mechanism to regulate bp (1)

Answer 31

kidney control (renin-angiotensin system)

reduced kidney flow
prorenin-> renin (juxtaglomerular cells)
angiotensinogen -> angiotensin I (renin)
angiotensin I -> angiotensin II (angiotensin-converting enzyme ACE)

angiotensin II does stuff like:
arteriolar vasoconstriction (increase bp) 
stimulates vasopressin (ADH) release 
stimulates aldosterone (increase Na+ and water reabsorption)

Question 32

velocity of blood flow depends on branching

Answer 32

more branching, increase cross SA, decrease velocity of flow and bp
opposite for merging veins