Anatomy - Autonomic Transmitters And Receptors

Front 1

How many neurons are in the somatic motor pathway?

Back 1

one

Front 2

What does a cholinergic neuron secrete? adrenergic neuron?

Back 2

cholinergic = ACh

adrenergic = Epi or NorEpi

Front 3

Where are the cell bodies of sympathetic neurons? parasympathetic?

Back 3

S = T1-L2

P = CN 3, 7, 9, 10 & Sacral S2-4

Front 4

What are the two types of cholinoreceptors? what do they bind?

Back 4

M (muscarinic) or N (nicotinic)

bind ACh

Front 5

What type of neurons and receptors (on effector organs) are in somatic motor?

Back 5

Cholinergic neurons, all N receptors on skeletal muscle

Front 6

What are all pre-ganglionic neurons in the symp and parasymp system?

Back 6

cholinergic (ACh)

note: ALL receptors for preganglionics are N, all postganglionic receptors (for those secreting ACh) are M

Front 7

What are the different types of adrenoreceptors? where are they found?

Back 7

a1, a2, b1, b2

smooth and cardiac muscle, glands

Front 8

what are the two different "pathways" in the sympathetic system?

Back 8

Cholinergic preganglionic --> ACh [N] (same for start of both)

1. Adrenergic Postganglionic --> NE [adrenoreceptors] on smooth and cardiac muscles and glands
* 2. Cholinergic Postganglionic --> ACh [M] on *sweat glands/thermoregulation*

Front 9

What part of the nervous system are the adrenal medulla? how do they differ in their form and function?

Back 9

Sympathetic (Greater splanchnic nerves), do not have processes, so no second neuron. First synapse occurs on ad. medulla (bypasses sympathetic chain ganglia), then Epi and NorEpi are released directly into circulation

Front 10

What are the cells in the adrenal medulla? what do they secrete and where?

Back 10

Chromafin cells

Epi and NorEpi directly into circulation

Front 11

What types of receptor is on all postganglionic autonomic neurons and chromaffin cells?

Back 11

Nicotinic receptors (N)

Front 12

Are the [N] receptors in the somatic and autonomic system identical?

Back 12

similar, but not identical

(hemamethonium block ganglia, but not motor end plates)

Front 13

What is the mechanism of action for [N] receptors? for [M]?

Back 13

ACh binds receptor [N] --> Na/K channel opens --> depol/AP

G-protein linked (cAMP or IP3 second messengers)
*same mechanism for Adrenoreceptors

Front 14

Where are [M] receptors found?

Back 14

All effector organs of the parasympathetic nervous system and sweat glands in the sympathetic system

Front 15

What are a1, a2, b1, b2? do they all have the same mechanism of action?

Back 15

Adrenoreceptors (Epi/NorEpi)

b1 and b2 are the same (adenylyl cyclase, cAMP); a1 and a2 are different and different from the betas

Front 16

*What type of adrenoreceptor leads to contraction of vascular smooth muscle? which leads to relaxation of vascular smooth muscle?

Back 16

a1 -- activation leads to contraction

b2 -- activation lead to relaxation (dilation)

recall: this is ALL within sympathetic nervous system

Front 17

which sympathetic receptor is very important in the heart? what does it's activation lead to?

Back 17

b1 -- found in SA and AV node and ventricular myocardium

activation leads to INCREASED heart rate, higher lypolysis and renin secretion (beta BLOCKERS counteract this)

Front 18

What is the class of molecules that includes Dopamine, Norepinephrine, and Epinephrine?

Back 18

Catecholemines (catechol is base component of all three)

Front 19

Do the adrenoreceptors all react equally to Epi and NorEpi?

Back 19

No.

Front 20

** how do the adrenoreceptor react differently to Epi and NorEpi?

Back 20

a1 & a2: circulating Epi/NE released from Adrenal Medulla not sufficient, must receive higher concentration from direct synapse of postganglionic sympathetic neuron

b1: more sensitive than alpha's. EPI and NE have same potency, can be activated by synapse of neuron OR adrenal medulla

b2: EPI more potent than NE; NO innervation, ONLY excited by EPI FROM ADRENAL MEDULLA

Front 21

In general, at a normal state, does the parasympathetic or sympathetic system predominate?

Back 21

parasympathetic

- keeping HR down, etc.

Front 22

What type of compounds are ganglion blockers? what effect do they have

Back 22

anticholinergenic

block nicotinic [N] receptors--> effect of blocking dominant system/stimulating non-dominant system --> "natural" state prevails, e.g. increased heart rate

Front 23

FYI CONCEPT: you can have the same effect in the ANS by either exciting a system OR inhibiting it's antagonist

Back 23

FYI: see chart

Front 24

What is the effect of Cholinergic drugs? what about Anticholinergic drugs?

Back 24

cholinergic agonists --> excite cholinergic receptors (a.k.a. anti-andregenics)

Anticholinergics are "adrenergics" mostly anti-muscarinics; anti-nicotinics are generally muscle relaxers (recall: somatic motor)