Parasympathetic Nervous System

Question 1

Name the physiological responses in the parasympathetic nervous system (7)

Answer 1

Constricts pupil
Stimulates saliva and tear production
Constricts bronchi
Slows heart 
Stimulates stomach, pancreas and intestines
Stimulates urination
Promotes genital erection

Question 2

What are the effects of the parasympathetic nervous system on the heart?

Answer 2

Decreases force of contraction

Reduces heart rate

Question 3

What are the effects of the parasympathetic nervous system on blood vessels?

Answer 3

ACh produces considerable vasodilation to systemic arteries

For less parasympathetic innervation to arteries

Question 4

What are the effects of the parasympathetic nervous system on male genetalia?

Answer 4

Dilution of penile artery

Engorgement of corpus cavernosum

Question 5

What are the effects of the parasympathetic nervous system on non-vascular smooth muscle?

Answer 5

Contraction of the bladder detrusor, airway, GI tract, uterus

Question 6

What are the effects of the parasympathetic nervous system on the eye?

Answer 6

Contracts circular muscle -> narrowing of pupil

Allows lens to bulge, therefore focussing the eye

Question 7

Name an industrial cholinesterase inhibitor in the parasympathetic nervous system and its use

Answer 7

Parathion - insecticide

Question 8

What are the symptoms when ACh is inhibited in the parasympathetic nervous system?

Answer 8

Increased:
Bowel motility
Acid secretion
Salivation
Lacrimation

Bradycardia
Hypotension
Focussing problems (eyes)
Urination

Question 9

Name the short acting cholinesterase inhibitors

Answer 9

Neostigmine

Physostigmine

Question 10

Name the long acting cholinesterase inhibitors

Answer 10

Edrophonium

Parathion

Question 11

Name the nicotinic cholinoceptors

Answer 11

N1 or Nm

N2 or Nn

Question 12

Name the muscarinic cholinoceptors

Answer 12

M1, M2, M3, M4, M5

Question 13

Where are the N1 cholinoceptors found?

Answer 13

Skeletal muscle

Question 14

Where are the N2 cholinoceptors found?

Answer 14

Autonomic ganglia

CNS

Question 15

Where are the M1 cholinoceptors found?

Answer 15

CNS
Peripheral neurones
Gastric parietal cells

Question 16

Where are the M2 cholinoceptors found?

Answer 16

Atria, SAN, AVN

Question 17

Where are the M3 cholinoceptors found?

Answer 17

Visceral smooth muscle,
secretory glands
Endothelial cells

Question 18

Where are the M4/M5 cholinoceptors found?

Answer 18

CNS

Question 19

Name the (2) selective agonists for nicotinic cholinoceptors

Answer 19

Nicotine

Lobeline

Question 20

Name the (3) selective antagonists for nicotinic cholinoceptors

Answer 20

Tubocurarine
Hexamethonium
Pancuronium

Question 21

Name the (3) selective agonists for muscarinic cholinoceptors

Answer 21

Muscarine, bethanecol, pilocarpine

Question 22

Name the (4) selective antagonists for muscarinic cholinoceptors

Answer 22

Ipratropium
Atropine
Hyoscine
Pirenzepine

Question 23

What is the enzyme and location for the M1 receptor?

Answer 23

Phospholipase C

Glands, secretory cells

Question 24

What is the enzyme and location for the M2 receptor?

Answer 24

Adenylate cyclase (Gi)

Heart

Question 25

What is the enzyme and location for the M3 receptor?

Answer 25

Phospholipase C (Gq) Endothelial cells, visceral smooth muscle GI secretions

Question 26

What is the enzyme and location for the M4 receptor?

Answer 26

Adenylate cyclase (Gi) CNS

Question 27

What is the enzyme and location for the M5 receptor?

Answer 27

Phospholipase C (Gq) CNS

Question 28

What are odd numbered muscarinic receptors positively coupled with?

Answer 28

Phospholipase C

Question 29

What are even numbered muscarinic receptors negatively coupled with?

Answer 29

Adenylate cyclase

Question 30

What does negatively coupled mean?

Answer 30

Reducing the amount of cAMP

Question 31

What happens in the heart when the beta gamma subunit activates a potassium channel?

Answer 31

The membrane potential hyperpolarises which limits activation

Question 32

How does activation of M3 receptors contract non-vascular smooth muscle?

Answer 32

Increased activation of phospholipase C calcium is released binds to myosin light chain kinase turns on myosin

Question 33

Where are muscarinic receptors heavily expressed?

Answer 33

Endothelium

Question 34

What happens to the calcium produced by M3 receptors in the endothelium?

Answer 34

Activates the NO synthase NO binds to guanylyl synthase causing it to relax

Question 35

What does activation of M3 receptors cause?

Answer 35

``` Increased: Saliva Tears Gut acid Sweat Phospholipase C Calcium release ```