Pharmacology - chapter 3 - The Autonomic Nervous System

Question 0

All preganglionic nerves exiting the CNS are what kind of neurons?

Answer 0

Cholinergic neurons

Question 1

What are autonomic drugs?

Answer 1

Drugs that produce their primary therapeutic effects by mimicing or altering the the functions of the autonomic nervous system.

Question 2

from what regions of the CNS do the parasympathetic preganglionic arise?

Answer 2

CN III to the ciliary ganglion
CN VII to the sphenopalatine ganglion & the submandibular ganglion
CN IX to the otic ganglion
CN X(vagus acount for approx 90% preganglionic prasymp. fibers)
& S2-S4

Question 3

sympathetic & parasympathetic.. whats the third division of the ANS?

Answer 3

The enteric nervous system - GI tract, pancreas & gallbladder, is functionally independent of CNS.

Question 4

what is the predominant factor for controlling heart rate?

Answer 4

PANS by way of vagus nerve

Question 5

name four organs that ONLY have sympathetic innervation

Answer 5

adrenal medulla, kidney, pilomotor muscles & sweat glands

Question 6

Sympathetic innervation of adrenal medulla:

preganglionic sympathtic neuron release what neurotrnsmitter? –> acting on which receptor in medulla? —-> releasing what neurotransmitter? —> acting on which receptor on effector organ?

Answer 6

ACH –> nicotinic —> E/NE (80/20%) —> adrenergic receptor

Question 7

Autonomic parasympathetic flow:

preganglionic fibers –> transmitter? —> postsynaptic receptor? —> postganglionic transmitter? —> Receptor on effector organ?

Answer 7

Ach –> nicotinic receptor –> Ach –> muscarinic receptor

Question 8

Postganglionic renal smooth muscle is innervated by …

Answer 8

dopaminergic neurons

Question 9

Parasympathetic postganglionic neurons are directed towards a specific organ with few branches. Where is the one place where the parasympathetic neurons is known to branch?

Answer 9

The myenteric plexus, where one preganglionic neuron have been found to branch with over 8000, or more, postganglionic fibers.

Question 10

what is a homeostatic reflex?

Answer 10

A neuronal compensatory mechanism for maintaining a body function at a predetermined level, e.g. the baroreceptor reflex.

Question 11

Botulinum toxin is a very large molecule, but despite this fact it is able to enter the cholinergic nerve endings. How?

Answer 11

Botulinum toxin is too big to diffuse across membranes. It interacts with botulinum-binding receptors and is then endocytosed. Botulinum-binding receptors are present on cholinergic neurons, but not on adrenergic neurons.

Question 12

Metyrosine?

Answer 12

Block NE synthesis. Me(tyrosine) inhibits tyrosine hydroxylase coversion of tyrosine —> DOPA.

Question 13

The pupil and SA node(in young adults) are both dominated by this branch of ANS?

Answer 13

PANS

Question 14

Mechanisms:

1 Hemicholinium
2 Metyrosine(alpha-metyltyrosine)

Answer 14

1 blocks uptake if choline in ACh synthesis

2 blocks tyrosine hydroxylase

• both messes with transmitter synthesis.

Question 15

Mechanisms:

1 Vesamicol
2 Reserpine

Answer 15

1 prevents storage and depletes ACh

2 prevents storage and depletes NE, serotonin and dopamin

Question 16

Mechanisms:

1 Botulinum toxin
2 Alpha-latrotoxin

Answer 16

1 prevents ACh release - cause flaccid paralysis

2 causes explosive ACh release - induce tetanic paralysis(tetanus)

Question 17

What neuron do reserpine, cocaine and tyramine work on?

Answer 17

sympathetic postganglionic neuron