11. structure of ANS

Question 1

sympathetic fight of flight actions

Answer 1

heart inotropy and chronotropy (contraction force and rate)

vasoconstriction in gut

vasodilation in skeletal muscle

sensory awareness – eg vision

sweat secretion

Question 2

sympathetic ganglionic pre and post length

parasympathic

Answer 2

SNS: short pre, long post

PNS: long pre,short post

Question 3

SNS where do preganglionic fibres emerge from

Answer 3

T- L2 of spinal cord

innervate prevertebral or paravertebral

Question 4

Answer 4

Question 5

sympathetic outflow from spinal cord I

Answer 5

Question 6

sympathetic outflow from spinal cord II

Answer 6

Question 7

sympathetic outflow from spinal cord III

Answer 7

pre synapses at several segments upwards

Question 8

sympathetic outflow from spinal cord IV

Answer 8

pre moves through paravertebral chain and synapse at splanchnic nerve

Question 9

PNS characteristics and nerves

Answer 9

cranio-sacral outflow: two exits for pre-ganglionic fibres beginning and base of spinal cord

Cranial nerves III (occulomotor), VII (facial), IX (glossopharyngeal), X (vagus)

sacral: bladder, lower GI, genitalia

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

tissues with only sympathetic innervation

Answer 14

adrenal medulla

piloerector muscles

sweat glands

spleen

many blood vessels

Question 15

tissues with only parasympathetic innervation

Answer 15

ciliary muscle (eye)- contracts thickens lens for close and focused vision

constrictor pupillae (eye)

radial are supplied with SNS

Question 16

Answer 16

Question 17

what happens when radial muscles contract

Answer 17

increase pupil diameter

Question 18

what happens when circular muscles contract

Answer 18

decrease pupil diameter (PNS)

Question 19

direct and consensual pupil reflex

Answer 19

Question 20

parasympathomimetics

Answer 20

Agonists of parasympathetic systems

pilocarpine (mACh agonist),

physostigmine (indirect action - increasing Ach by preventing breakdown)

miosis (constriction of the pupil),

decrease in near point (able to focus on near objects),

decrease in intraocular pressure (IOP)

Question 21

parasympatholytics

Answer 21

Blockers of parasympathetic systems

e.g. muscarinic receptor antagonists - tropicamide

mydriasis (dilation of pupil),

cycloplegia (loss of accommodation),

increased IOP

Question 22

Sympathomimetics

Answer 22

Agonists of sympathetic systems

eg adrenaline (agonist),

amphetamine (indirect action – increase NA)

Effects

mydriasis (excessive dilation of pupil),

increased IOP

Question 23

Sympatholytics

Answer 23

Blockers of sympathetic systems

ie adrenoceptor antagonists eg phentolamine

Effect

= miosis (constriction of pupil).