MR 11 The ANS

Question 1

What in general does sympatheitic nervous system do?

Answer 1

Fight or flight

inc HR, force of contraction, bp

Question 2

What in general does parasympathetic nervous system do?

Answer 2

rest and digest

regulates basal activities

Question 3

Where does parasympathetic nervous system originate?

Answer 3

Horn of medulla and sacral regions

Question 4

Where does sympathetic nervous system originate?

Answer 4

Thoracolumbar regions

Question 5

Which neurones are myelinated in ANS, preganglionic or postganglionic?

Answer 5

Pre-ganglionic

Question 6

What are the lengths of parasympathetic neurones?

Answer 6

Long preganglionic, short post ganglionic

Question 7

Where are the ganglia in parasympathetic nerves?

Answer 7

In the tissues innervated by the postsynaptic fibres

Question 8

What are the lengths of sympathetic neurones?

Answer 8

Short pre-ganglionic, long post-ganglionic

Question 9

Where are the ganglia in sympathetic neurones?

Answer 9

in paravertebral chain close to spinal cord

Question 10

What transmitter do pre-ganglionic neurones use?

Answer 10

Acetylcholine

are cholinergic

Question 11

Which postganglionic neurones transmit Ach? What receptors does this activate?

Answer 11

Parasympathetic

activates muscarinic receptors

Question 12

What type of receptors are muscarinic receptors?

Answer 12

Ach

G-protein coupled

Question 13

What transmitter do most sympathetic post gangionic neurones use and on what receptors?

Answer 13

NA
alpha adrenoceptors(a1 a2)and beta adrenoceptors(b1, b2, b3)

Question 14

What type of receptors are adrenoceptors?

Answer 14

G- protein coupled

NA and adrenaline

Question 15

Which sympathetic post ganglionic neurones are cholinergic?

Answer 15

sweat glands, hair follicles (piloerection)

Question 16

What are Non-Adrenergic, Non-Cholinergic (NANC) transmitters? Give examples

Answer 16

Transmitters that may be co-released with NA or ACh

e.g ATP, NO, 5-hydroxytryptamine (5HT/serotonin), neiropeptides

Question 17

What are chromaffin cells?

Answer 17

Postganglionic sympathetic neurones in adrenal glands that don’t project to a target tissue but instead secrete adrenaline

Question 18

Where are chromaffin cells founs?

Answer 18

Adrenal medulla

Question 19

What do M2 receptors do and at what site?

Answer 19

Cause bradycardia -SA node

Reduce cardiac conduction velocity -AV node

Question 20

Where are M3 receptors found? What do they do?

Answer 20

Smooth muscle
Bronchial contraction
Inc intestinal mobility and secretion
Bladder contraction (detrusor) and relaxtion (trigone/sphincter)
Penile erection
Ciliary muscle and iris contraction in eye

Question 21

Which receptors are responsible for increased sweat, salivary and lacrimal secretion?

Answer 21

m1/m3

Question 22

Which sypathetic receptors are found in the heart, what do they do?

Answer 22

b1
cause tachycardia at SA node
cause positive inotropy in ventricles

Question 23

Which receptors are responsible for bronchial/intestinal/ uterine relaxation?

Answer 23

b2

sympathetic

Question 24

What are some ANS disorders?

Answer 24

Catecholamine disorders
Central autonomic disorders
Orthostatic intolerance syndrome
Paroxysmal autonomic syncopes
Peripheral autonomic disorders

Question 25

What is familial Dysautonomia (FD)?

Answer 25

Autosomal recessive disorder affecting development and survival of sympathetic and some parasympathetic neurones Almost exlusively askenazi jewish descent Infants often present due to feeding and swallowing difficulties Symptoms include dysautonomic crises, GI tract dyscoordination, CV and resp dysfunction, altered sensory perception, spinal curvature

Question 26

Via which nerve do chemoreceptors in the carotid body relay information to the CNS? What do these sense?

Answer 26

Glossopharangeal nerve | Blood O2, CO2 and pH

Question 27

What is the nucleus tractus solitarius?

Answer 27

The "Second order" sensory neurons in medulla oblongata that primary sensory neurones project onto that integrates all the visceral afferent info

Question 28

What does choline acetyltransferase do?

Answer 28

Combine Acetyl CoA and choline to acetylcholine and CoA

Question 29

What does acetylcholinesterase do?

Answer 29

Break Ach into acetate and choline

Question 30

Where does trimetaphan act, why? What does it do?

Answer 30

Acts on nAchRs at autonomic ganglia Here but not at NM junctions as receptors differ in structure Blocks ganglion in anaesthetic procedures

Question 31

How many types of mAChRs are there? Are drugs affecting these used?

Answer 31

5types | Not really very few agonists and antagonists clinically available often as little selectivity

Question 32

What group of receptors does tolterodine affect, what is it used to treat?

Answer 32

mAChRs | overactive bladder