lecture 7 - autonomic NS

Question 1

ANS operates without conscious control via

Answer 1

reflex arcs to regulate activity of smooth muscle, glands, and cardiac muscle

Question 2

components of ANS reflex arc

Answer 2

sensory receptors (mostly interoceptors)
sensory neurons
integrating centres in CNS (brainstem and hypoth)
motor neurons
visceral effectors

Question 3

ANS vs SNS - sensory input

Answer 3

ANS - mainly interoceptors, some from somatic senses/special senses

SNS - from somatic senses/special

Question 3

ANS vs SNS - motor neuron pathway

Answer 3

ANS - usually 2 neuron, pre and post ganglionic. OR preganglionic neurons may synapse with cormaffin cells

SNS - one neuron pathway, from CNS directly with affector

Question 3

ANS vs SNS - NTs and hormones

Answer 3

ANS - all preganglionic = ACh, most synpathetic post ganglionic = NE, most parasympathetic post ganglionic = ACh, cromaffin cells = E/NE

SNS - all somatic motor neurons release only ACh

Question 3

ANS vs SNS - control of motor output

Answer 3

ANS - involuntary control from hypothalamus, limbic system, brainstem and spinal cord

SNS - voluntary control form C cortex, corpus striatum, cerebellum, brainstem, cord

Question 3

ANS vs SNS - effectors

Answer 3

ANS - smooth muscle, cardiac, glands

SNS - skeletal muscle

Question 4

sympathetic division ______ organ function

Answer 4

excites

Question 4

ANS vs SNS - responses

Answer 4

ANS - contraction/relaxation of smooth muscle, increased/decreased rate/force of cardiac contraction, +/- secretions of glands

SNS - contraction of skeletal muscle

Question 5

parasympathetic division ______ organ function

Answer 5

inhibits

Question 6

dual innervation

Answer 6

when an organ is supplied by both para and sympathetic fibres

Question 7

preganglionic neuron

Answer 7

myelinated, extends to autonomic ganglion or chromaffin cells

Question 8

postganglionic neuron

Answer 8

extends from autonomic ganglion, nonmyelinated, extends to effector

Question 9

hypothalamus regulates:

Answer 9

balance between symapthetic and parasympathetic activity levels

Question 10

autonomic tone

Answer 10

total activity rate of the ANS, balances the two divisions

Question 11

sympathetic components of the ANS

Answer 11

preganglionic neurons
autonomic ganglion
sympathetic ganglion
postganglionic neurons

Question 12

parasympathetic components of the ANS

Answer 12

preganglionic neurons
autonomic ganglions
parasympathetic ganglion
postganglionic neurons

Question 13

organization of the ANS (generic pathway)

Answer 13

CNS, preganglionic neurons, ganglion/chromaffin,, postganglionic neuron, effector

Question 14

thoracolumbar division is where

Answer 14

cell bodies of preganglionis neurons are located in SNS (lateral grey horns)

t1-L2

Question 15

sympathetic trunk (chain) ganglia are located

Answer 15

on either side of the spinal cord

Question 16

facts about sympathetic trunk (chain) ganglion (

Answer 16

extend from skull base to coccyx

receive axons from thoracolumbar segements

form superior, middle and inferior cervical ganglia

close to spinal cord

Question 17

sympathetic pregangionic neurons are long or short

Answer 17

short

Question 18

sympathetic postgangionic neurons are long or short

Answer 18

long

Question 19

prevertebral ganglia are located

Answer 19

anterior to vertebral column

Question 20

prevertebral ganglia consist of how many ganglia

Answer 20

5

Question 21

prevertebral ganglia innervates mostly

Answer 21

organs below the diaphragm

Question 22

4 options of a preganglionic neuron (pathways to get somewhere)

Answer 22

1. same level 2. higher or lower 3. goes to prevertebral ganglion 4. goes to chromaffin cells

Question 23

option details for preganglionic neuron once it leaves the cord) - 1. stays at same level

Answer 23

axon exits cord, does a loop through white communicating ramus to sympathetic trunk ganglion, synapses in ganglion and leaves thru grey communicating ramus

Question 24

option details for preganglionic neuron once it leaves the cord) - 2. higher or lower

Answer 24

exact same as 1 but when the axon gets to the trunk ganglion, it goes up or down the trunk before exiting via grey communicating rami (exit cord, white com ramus -> sympathetic trunk ganglion (moves up or down) -> grey com ramus)

Question 25

option details for preganglionic neuron once it leaves the cord) - 3. axon synapses in prevertebral ganglion

Answer 25

exits cord, enters symp trunk ganglion via white com ramus, continues thru a splanchnic nerve to a prevertebral ganglion

Question 26

option details for preganglionic neuron once it leaves the cord) - 4. axon goes to chromaffin cells

Answer 26

exits cord, goes to trunk ganglia via white com ramus, continues thru splanchnic nerve to chromaffin cells

Question 27

white communicating ramus

Answer 27

short pathway where axons enter the sympathetic trunk ganglia after exiting the spinal cord (far track on diagrams) myelinated axons - hence white connects spinal nerve to chain ganglia

Question 28

grey communicating ramus

Answer 28

short pathways where axons in sympathetic trunk ganglia return to the spinal nerve (close track to SC on diagram) unmyelinated axons - hence grey connect ganglia of sympathetic trunk to spinal nerves

Question 29

in the sympathetic NS which axons are long and short?

Answer 29

long - postganglionic short - preganglionic this means that ganglia (being prevertebral or in the trunk) are close to CNS

Question 30

how many postganglionic neurons can one preganglionic neuron synapse within the SNS

Answer 30

up to 20, supplying many body regions

Question 31

cervical ganglia innervate:

Answer 31

heart and head (all glands)

Question 32

thoracic ganglia innervate:

Answer 32

heart, lungs, skin (all glands)

Question 33

hypogastric plexus innervates:

Answer 33

pelvis visceral effectors

Question 34

preganglionic axons that pass thru the symapthetic trunk without synapsing in it are called? what options are these part of?

Answer 34

splanchnic nerves part of options 3 and 4 extend to prevertebral ganglia or chromaffin cells

Question 35

suprarenal medulla houses

Answer 35

chromaffin cells

Question 36

chromaffin cells function

Answer 36

secrete hormones into the bloodstream (NE and E)