ANS

Question 1

somatic motor neuron pathway

Answer 1

no interneuron use
single long myelinated motor neuron to effector

release of acetylecholine from motor neuron
- act on nicotinic receptors

Question 2

autonomic motor neuron pathway

Answer 2

interneuron use
myelinated pre-ganglionic neuron
unmyelinated post-ganglionic neuron

release of acetylcholine from pre-ganglionic neuron
- act on nicotinic receptors

release of acetylcholine or noradrenaline from post-ganglionic
- act on muscarinic or adrenergic receptor

Question 3

sympathetic motor neuron pathway

Answer 3

short myelinated pre-ganglionic neuron
long unmyelinated post-ganglionic neuron

noradrenaline release
acts on adrenergic receptors

Question 4

parasympathetic motor neuron pathway

Answer 4

long myelinated pre-ganglionic neuron
short unmyelinated post-ganglionic neuron

acetylcholine release
act on muscarinic receptors

Question 5

location of parasympathetic pre-ganglionic neurons

Answer 5

brainstem cranial nerves:
III, VII, IX, X
(oculomotor, facial, glossopharyngeal, vagus)

spinal cord spinal nerves:
S2 - S4

craniosacral outflow (top and bottom)

Question 6

location of sympathetic pre-ganglionic neurons

Answer 6

spinal cord spinal nerves:
T1 - L2

thoracolumbar outflow (central)

Question 7

location of parasympathetic ganglia

Answer 7

cranial nerves:
III, VII, IX = synapse glanglia in the head
X and S neurons = synapse near target

• generally near target due to long pre-ganglionic neuron

Question 8

location of sympathetic ganglia

Answer 8

ganglia form sympathetic chain
- linking of many neurons down the sides of the spinal column
- allows extension from cranial base to coccyx
- extends length of spinal cord in sympathetic trunk

• generally further from target due to short pre-ganglionic neurons

Question 9

muscarinic receptors
- receptor type
- receptors and location

Answer 9

g-protein coupled
M1 = CNS
M2 = heart
M3 = smooth muscle/glands

Question 10

adrenergic receptors
- receptor type
- receptors and location

Answer 10

g-protein coupled
alpha1 = smooth muscle (vessels)
alpha2 = CNS, PNS
beta1 = heart
beta2 = airway smooth muscle

Question 11

central control of ANS

Answer 11

1. input from sensory/motor cortex, limbic system and nucleaus tractus solitarius (NTS) relayed to hypothalamus
2. hypothalamus and NTS relays info to the ANS brainstem centres
3. brainstem centres induce changes in para/sympathetic activity

• visceral afferents feed info to the NTS

Question 12

adrenal medulla (of the kindey) innervation
- and composition

Answer 12

directly innervated by pre-ganglionic sympathetic neurons
- acts as a modified sympathetic ganglion

composed of specialised neuroendorcine cells for secretion of adrenaline into the bloodstream

Question 13

muscarinic antagonists

Answer 13

e.g. atropine, belladonna
used in surgery to prevent parasympathetic reflexes

reduces contraction

Question 14

beta-adrenergic antagonists

Answer 14

e.g. propranolol
slows heart rate to prevent arrhythmia
- can be used to treat hypertension

Question 15

alpha-adrenergic agonists

Answer 15

e.g. salbutamol
promotes bronchodilation
- used to treat asthma

Question 16

atropine
belladonna

Answer 16

muscarinic antagonists

Question 17

propranolol

Answer 17

beta-adrenergic antagonists

Question 18

salbutamol

Answer 18

alpha-adrenergic agonists