Mechanoreceptors

Question 1

How do mechanoreceptors differ?

Answer 1

Threshold
Range
AP frequency
Sensitivity

Question 2

Where are arterial baroreceptors found?

Answer 2

Aortic Arch
Carotid sinuses
Coronary arteries

Question 3

Where are cardiopulmonary mechanoreceptors found?

Answer 3

Cardiac chambers
Veno-arterial regions
Pulmonary arteries

Question 4

How do carotid sinus baroreceptors relay information?

Answer 4

Via carotid sinus and glossopharyngeal nerves

Question 5

How do aortic arch baroreceptors relay information?

Answer 5

Via aortic and vagus nerves

Question 6

What do baroreceptors provide information to?

Answer 6

NTS in medulla oblongata

Question 7

What is baroreceptor activity influenced by?

Answer 7

MAP
pulse pressure

Question 8

What does an increase in MAP cause?

Answer 8

Increase of baroreceptor firing

Question 9

Describe the features of A fibres?

Answer 9

Large diameter
Myelinated
Lower threshold
Has a saturation point
More sensitive

Question 10

Describe the features of C fibres?

Answer 10

Narrow diameter
Unmyelinated
Still respond at high <AP

Question 11

What does saturation of A fibres cause?

Answer 11

Recruitment of C fibres

Question 12

Where are veno-atrial stretch receptors found?

Answer 12

Veno-atrial junctions eg. pulmonary vein and left atrium

Question 13

What type of fibres are veno-atrial stretch receptors?

Answer 13

Myelinated fibres

Question 14

What nerve do veno-atrial stretch receptors project through?

Answer 14

Vagal arterial nerve

Question 15

What increases firing of veno-atrial stretch receptors?

Answer 15

Increase in venous return

Question 16

Where are cardiac mechanoreceptors found?

Answer 16

Atria and ventricles

Question 17

What type of fibres are cardiac mechanoreceptors?

Answer 17

Non-myelinated

Question 18

What nerve do cardiac mechanoreceptors project through?

Answer 18

Vagus and cardiac sympathetic nerve

Question 19

What fibres are pulmonary artery mechanoreceptors?

Answer 19

Non-myelinated

Question 20

What do arterial and cardiopulmonary baroreceptors cause?

Answer 20

Net depressor influence on arterial pressure

Question 21

What do arterial baroreceptors maintain?

Answer 21

MAP

Question 22

What do cardiopulmonary baroreceptors inhibit?

Answer 22

Arterial pressure

Question 23

What does stimulation of veno-atrial stretch receptors cause?

Answer 23

Reflex tachycardia

Question 24

What mediates reflex tachycardia?

Answer 24

Increase in sympathetic outflow to SA node

Question 25

What does reflex tachycardia produce?

Answer 25

Faster shift of blood to arterial system

Question 26

What does reduced renal sympathetic nerve activity cause?

Answer 26

Reflex diuresis and natriuresis -> increase in urine output

Question 27

What is the Bainbridge Reflex?

Answer 27

Tachycardia stimulated by a large rapid infusion of saline into the venous system

Question 28

What is the Bainbridge reflex triggered by?

Answer 28

Stimulation of veno-atrial stretch receptors and distension of the pacemaker

Question 29

What are cardiac mechanoreceptors?

Answer 29

Network of fine unmyelinated fibres

Question 30

Where are cardiac mechanoreceptors found?

Answer 30

Atrial fibres and LV mechanoreceptors

Question 31

What are atrial fibres triggered by?

Answer 31

Larger atrial distension

Question 32

What are LV mechanoreceptors triggered by?

Answer 32

Ventricular distension due to filling by preload

Question 33

What does activation of cardiac mechanoreceptors cause?

Answer 33

Depressor effect
Reflex bradycardia and vasodilation - baroreflex