Physiology - Part 2

Question 1

which neurotransmitter do sympathetic nerves release?

Answer 1

noradrenaline

Question 2

where else does adrenaline come from?

Answer 2

adrenal medulla

Question 3

which receptors do sympathetic nerves act on?

Answer 3

beta 1 receptors on sinoatrial node and myocytes

Question 4

what effect do sympathetic nerves have on the pacemaker potential?

Answer 4

increases the slope

Question 5

what effect do sympathetic nerves have on heart rate?

Answer 5

increase

Question 6

which neurotransmitter do parasympathetic nerves release?

Answer 6

acetylcholine

Question 7

which receptors do parasympathetic nerves act on?

Answer 7

muscarinic receptors on the sinoatrial node

Question 8

what effect do parasympathetic nerves have on the pacemaker potential?

Answer 8

hyperpolarises and decreases the slope

Question 9

what effect do parasympathetic nerves have on heart rate?

Answer 9

decrease

Question 10

what does starling’s law state in relation to preload?

Answer 10

the energy of contraction is proportional to the initial length of the cardiac muscle fibre

Question 11

what effect does increased venous return have on the heart?

Answer 11

increased end diastolic volume –> increased stroke volume

Question 12

what effect does decreased venous return have on the heart?

Answer 12

decreased end diastolic volume –> decreased stroke volume

Question 13

what is preload?

Answer 13

the end diastolic volume the heart must pump out

Question 14

what is afterload?

Answer 14

the systolic pressure against which the heart must work to eject blood during systole

Question 15

what happens to stroke volume if the total peripheral resistance increases?

Answer 15

decreases

Question 16

is preload affected by the venules/veins (capacitance vessels) or the arterioles (resistance vessels)?

Answer 16

venules/veins (capacitance vessels)

Question 17

is afterload affected by the venules/veins (capacitance vessels) or the arterioles (resistance vessels)?

Answer 17

arterioles (resistance vessels)

Question 18

what effect do sympathetic nerves have on stroke volume?

Answer 18

increase contractility

Question 19

what effect do parasympathetic nerves have on stroke volume?

Answer 19

little to no effect - vagus doesn’t innervate ventricles

Question 20

what effect does hypercalcemia have on the stroke volume - end diastolic volume curve?

Answer 20

shifts curve up and to the left

Question 21

what effect does hypocalcemia have on the stroke volume - end diastolic volume curve?

Answer 21

shifts curve down and to the right

Question 22

what effect does ischaemia have on the stroke volume - end diastolic volume curve?

Answer 22

shifts curve down and to the right

Question 23

what effect do barbiturates have on the stroke volume - end diastolic volume curve?

Answer 23

shifts curve down and to the right

Question 24

CO = ? x?

Answer 24

CO = HR x SV

Question 25

what’s the fancy name for a blood pressure cuff?

Answer 25

sphygmomanometer

Question 26

does gravity affect the driving pressure from arteries to veins?

Answer 26

no

Question 27

what is the pressure drop through the arteries?

Answer 27

small - ~95-90 mmHg

Question 28

what is the pressure drop through the arterioles?

Answer 28

large - ~90-40 mmHg

Question 29

what is the pressure difference pushing blood back through the veins?

Answer 29

small - ~20-5 mmHg

Question 30

where might you find a continuous capillary with no clefts or channels?

Answer 30

brain

Question 31

where might you find a continuous capillary with only clefts?

Answer 31

muscle

Question 32

where might you find a fenestrated capillary?

Answer 32

intestine

Question 33

where might you find a discontinuous capillary?

Answer 33

liver

Question 34

what effect do prostacyclins and nitric oxide have?

Answer 34

inhibit platelet aggregation

Question 35

what effect does tissue factor pathway inhibitor (TFPI) have?

Answer 35

stops thrombin production

Question 36

what effect does thrombomodulin have?

Answer 36

binds thrombin and inactivates it

Question 37

what effect does heparin have?

Answer 37

inactivates thrombin

Question 38

what effect does tissue plasminogen activator (t-PA) have?

Answer 38

converts plasminogen to plasmin which digests the clot

Question 39

what is oedema?

Answer 39

accumulation of excess fluid

Question 40

what can cause oedema?

Answer 40

lymphatic obstruction
raised CVP
hypoproteinemia
increased capillary permeability