Karius Autonomics 1 Lecture

Question 1

the AUTONOMIC reflex Arc: the effector neuron

Answer 1

begins in the CNS and ends in the periphery and is equivalent of the motorneuron

Question 2

unlike the “withdrawal reflex” most of the integration of autonomic reflexes occurs

Answer 2

within the brain although at lower levels, brainstem, hypothalamus, rather than the cortex

afferents ALWAYS go to the brain

Question 3

the ANS is part of peripheral nervous system that is specific for

Answer 3

smooth muscle and glands

Question 4

Sym

Answer 4

fight or flight

Question 5

Parasym

Answer 5

rest and digest

Question 6

ANS has ____ neurons in serious that will go to the effector cell

Answer 6

2 neurons

Question 7

Neuron #1 in the ANS is the

Answer 7

preganglionic, starts in the CNS (gets message from brain), leaves the CNS, travels to ganglion where it synapses on the second neuron in the pathway

Question 8

Neuron #2 in the ANS is

Answer 8

on the post ganglionic neuron, which then travels to the target organ and synapses on it

Question 9

How can we distinguish between the parasympathetic and sympathetic systems?

Answer 9

1. where the preganglionic fibers leave the CNS
2. location of the ganglions
3. length of the pre-post ganglionic axons

Question 10

Cranial and Sacral: which pre- ganglionic neurons leave from these two locations?

Thoracic and lumbar: which pre-ganglionic neurons leave from these two locations?

Answer 10

Parasympathetic C and S

Sym T and L

Question 11

Where are the ganglia located in the parasympathetic nervous system?

Where are the ganglia located in the sympathetic?

Answer 11

Para: on or near the target organ
for the heart for instance, they are directly on the heart

Sym: from the sympathetic chain (mostly)

Question 12

Sympathetic and Parasympathetic

short long or what

Answer 12

Para: PLS (parasym, long, then short)
Sym: SSL (sym, short, then long)

Question 13

Pre and Post synapsing: what NT for para?

Post and effector synapsing: what NT for para?

Answer 13

1. acetylcholine, binds to nAChR on the post-ganglionic dendrite causing an EPSP and leading to an AP in the neuron
2. ACh as well

Question 14

where are the nAChR on the post-ganglionic neuron in the parasympathetic nervous system?

Answer 14

on the dendrite, causing an influx of sodium

not voltage gated

Question 15

Metaphor for PARA synapses 1 and 2

Answer 15

the first is like the mailman carefully placing mail through the mailbox, the second is like the mailman throwing the mail from his window as he’s driving by (en pass, driving by)

Question 16

what makes the second synapse (postgang syapsing on the effector) distinct?

Answer 16

1. the postgang releases ACh from vericosities into a less well defined juncture that isn’t as protected, so substantial leakage of NT
2. the receptor on the effector is a mACh receptor (muscarinic receptor)

Question 17

M receptors

Answer 17

GPCRs

M2: cardiac: ACh activates Gi subunit, DECREASES cAMP, increasing gK

M3: widely distributed in the body, Gq coupled

M3: autoreceptors on neurons, Gi coupled (decreases cAMP causing DECREASE in ACh release

Question 18

ANS sympathetic: Pre-ganglionic NT

Answer 18

ACh

Question 19

ANS sympathetic: Post-ganglionic R @ synapse 1

Answer 19

nAChR on the dendrite, but the nicotinic receptor is different than the one in the parasympathetic nervous system

Question 20

ANS sympathetic: Post-gang synapsing on effector, NT

Answer 20

norepinephrine, which can bind to both alpha and beta adrenergic receptors

Question 21

Adrenal Medulla

Answer 21

within medulla there are CHROMAFFIN cells that produce epinephrine (some dopamine and norepinephrine)
AM is equivalent of a sympathetic ganglion

Question 22

What kind of neuron, neurotransmitter, and receptors are at work in the synapse with the adrenal medulla?

Answer 22

the synapse is between a preganglionic sympathetic neuron to release ACh to bind to an nAChR on the adrenal medulla chromaffin cells, causing it to release epinephrine to the blood

Preganglionic synapse acts on Chromaffin cells

Question 23

Chromaffin cells primarily release epinephrine cells but they also release norepinephrine and some dopamine. Why is that?

Answer 23

dopamine –> norepinephrine –> epinephrine –> into the blood