Physiology

Question 1

Characteristic of aorta

Answer 1

wide lumen,
elastic wall
damp pressure variations

Question 2

Characteristic of Arteries

Answer 2

wide lumen,
strong non-elastic wall
low resistance conduit

Question 3

Characteristic of arterioles

Answer 3

narrow lumen, thick contractile wall
control resistance & therefore flow
allow regional redirection of blood

Question 4

Characteristic of capillaries

Answer 4

narrow lumen, thin wall

Question 5

Characteristic of venules and veins

Answer 5

wide lumen, distensible wall
low resistance conduit, & reservoir
allows fractional distribution of blood between veins & rest of circulation

Question 6

What electrically connects cardiac cells

Answer 6

Gap junctions

Question 7

what physically connects cardiac cells

Answer 7

desmosomes

Question 8

Cardiac cells are connected. What is this called

Answer 8

syncytium

Question 9

In non-pacemaker cells, what causes initial fast polarisation

Answer 9

Influx of Na

Question 10

In non-pacemaker cells, What causes the plateau

Answer 10

Influx of Ca and release of K

Question 11

In non-pacemaker cells, what cause repolarisation

Answer 11

Influx of K and Release of Na

Question 12

In pacemaker cells, What causes polarisation

Answer 12

Influx of Ca

Question 13

In pacemaker cells, What causes early prepotential

Answer 13

k channels gradually closing

influx of Na

Question 14

In pacemaker cells, What causes late prepotential

Answer 14

influx of Ca

Question 15

What type of Ca is used in polarisation

Answer 15

L-type

Question 16

What type of Ca is used in prepotential

Answer 16

T-type

Question 17

sympathetic nervous system release what neurotransmitter

Answer 17

noradrenaline

Question 18

noradrenaline acts on what receptors on SA node

Answer 18

B1 receptors

Question 19

Where is adrenaline released from where

Answer 19

adrenal medulla

Question 20

Which parasympathetic nerve acts on the heart

Answer 20

vagus

Question 21

Vagus nerve releases what neurotransmitter

Answer 21

ACh

Question 22

Ach acts on what receptors on SA node

Answer 22

muscarinic

Question 23

What autonomic system affects construability

Answer 23

sympathetic

Question 24

noradrenaline and adrenaline affect which receptors on myocytes

Answer 24

B1

Question 25

What 3 things increase venous return

Answer 25

Venule tone skeletal-muscle pump respiratory pump

Question 26

equation for MAP

Answer 26

MAP=CO X TPR

Question 27

4 examples of intrinsic flow controls

Answer 27

1 accumulation of metabolites from exercise for example 2 accumulation of metabolites from continued low flow 3 reaction to hypoxia 4 injury response

Question 28

What autonomic system controls vasoconstriction of vessels

Answer 28

sympathetic

Question 29

Which neuro transmitter causes vasoconstriction

Answer 29

noradrenaline

Question 30

noradrenalin binds to what receptors causing vasoconstriction

Answer 30

A-1

Question 31

Parasympathetic role in flow distribution

Answer 31

no role except to genitalia and salivary glands

Question 32

which hormone affects central flow distribution

Answer 32

adrenaline

Question 33

What receptors does adrenaline bind to and the affect

Answer 33

B-2 affects cardiac and skeletal muscle increases supply (vasodilation) A-1 affects all other tissues causing vasoconstriction

Question 34

Where are the arterial baroceptors located

Answer 34

Aortic arch a | Carotid arteries

Question 35

Which nerve supplies sensory information to the brain form the aortic arch baroreceptor

Answer 35

Vagus nerve

Question 36

Which nerve supplies sensory information to the brain form the carotid baroreceptor

Answer 36

Glossopharyngeal nerve

Question 37

Talk through effects of Valsalva manoeuvre

Answer 37

1) Increased thoracic pressure is transmitted through to aorta – hence the immediate jump 2) Increased thoracic pressure reduces the filling pressure from the veins, which therefore  VR,  EDV,  SV,  CO,  MAP 3) The reduced MAP is detected by baroreceptors which initiate a reflex increase in CO and TPR 4) At end of the manoeuvre, the decrease in thoracic pressure is transmitted through to the aorta – hence the drop 5) VR is restored so SV , but reflex effects have not worn off 6) Eventually, back to normal

Question 38

What does the Renin-angiotensin-aldosterone system do to MAP

Answer 38

Increase

Question 39

What does Antidiuretic hormone do to MAP

Answer 39

Increase

Question 40

What does ANP and BNP do to MAP

Answer 40

decrease

Question 41

ANP and BNP are released by what and why

Answer 41

myocardial cells due to distention (sign of high MAP or fluid overload)