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Flashcards in Intro to ANS Deck (65):
1

ANS

portion of the central and peripheral NS that is responsible for unconscious control of the visceral function

2

Parasympathetic

CONSTANT control of visceral function

i.e. decreased heart rate, shunting of blood toward the gut away from the skeletal muscle

3

cranial part of the parasympathetic division

cranial nerves
III
VII
IX
X

4

sacral part of parasympathetic division

lateral horn (intermediolateral cell column)

S2
S3
S4

5

sympathetic division

responsible for control of visceral reaction response to IMMEDIATE STRESS (fight or flight)

6

thoracolumbar portion of sympathetic division

IMLCC lateral horn of spinal cord levels T1-L2

7

collection of neurons within the CNS?

nucleus

8

NOTE***
visceral efferent fibers of the ANS are accompanied by visceral afferent fibers

visceral afferents PARALLEL the course of the sympathetic division, generally carrying visceral pain

visceral afferents (mostly vagal) can be FOUND WITHIN branches of cranial nerves VII, IX and X . These are responsible for the modailty of distention (feeling full)

9

where are the presynaptic neuron cells bodies of the sympathetic nervous system found?

in the CNS--> intermediolateral cell column

the intermediolateral cell column is found from T1-L2

10

where do the cell bodies of postsynaptic neuron of the sympathetic NS reside?

2 types

paravertebral ganglia

AND

prevertebral ganglia

11

paravertebral ganglia

sympathetic trunk/chain ganliga

extend the length of the spinal column

attached to spinal nerve trunks (rami) which conduct specific nerve fibers (white and gray ramus communicans)

12

white ramus communicans

conduct MYELIN preganglionic sympathetic fibers from a spinal nerve to a paravertebral ganglion

13

Gray ramus communicans

conduct unmyelinated post-ganglionic sympathetic fibers from a paravertebral ganglion to a spinal nerve

14

pre-vertebral ganglia (collateral)

located ANTERIOR to the vertebral column (anterior to the aorta)

includes:
celiac
aorticorenal
superior and inferior mesenteric ganglia

15

preganglionic fiber of ANS

efferent fiber from the preganglionic neuron (cell bodies located within CNS)

16

postganglionic fiber of ANS

fiber from the second neuron (cell bodies located within peripheral ganglion)

17

for the parasympathetic nervous system where does the postganglionic fiber reside typically?

within the walls of organs that it innervates

EXCEPT in the head specifically where parasympathetic ganglia exist near organs (salivary glands and eyes)

18

what is the vagus nerve and what does it innervate

CNX

innervates thoracic and abdominal viscera (most of the GI tract)

19

sympathetic division of ANS innervates

all visceral organs AND visceral organs of the periphery

pass out INTO SPINAL NERVES

20

upper limb

T2-T7

21

lower limb

T10-L2/3

22

body wall

T7-L1

23

eyes

T1-T2

24

Head, salivary glands

T1-3,4 (head AND neck)

25

heart

T1-5

26

lungs

T2-6

27

Esophagus

T2-T8

28

stomach, liver, gallbladder, pancreas

T6-9

29

Small intestine

T8-T12

30

kidney

T10-L1

31

suprarenal gland

T5/6-L1 or L2

32

the sympathetic chain is attached to....

every single spinal nerve

33

why is the gray ramus ONLY postganglionic

there are no other ganglia peripherally other than the sympathetic chain
so everything that leaves by the gray ramus must be postganglionic

34

3 different pathways of preganglionic sympathetic fibers after passing through white rami communicants to sympathetic chain ganglia...

1- Synapase on a postganglionic neuron at the same LEVEL OF ENTRY (so T1-L2)

2- ascend or descend a few segments
-ascend --> head, neck and upper limb
-descend --> lower limb

3- pass through the sympathetic chain and ganglion without synapsing to pass via splanchnic nerve to a prevertebral ganglion

35

sympathetic chain ...

parallells ALL SPINAL NERVES

36

sympathetic inneration??

sweat glands and erector pilae muscles

37

splanchnic nerve?

a sympathetic PREGANGLIONIC fiber that does not synapse in a paravertebral ganglion, but rather synapses distally in a PREVERTEBRAL ganglion closer to the organs which they innervate

takes information to the gut

38

there are no preganglionic sympathetic fibers above T1 or below L2

so the only way you get preganglionic information into area that is opposite spinal nerves where there is no intermediolateral cell column is via sympathetic chain

39

what is found larger quantities?postsynaptic sympathetic fibers or presynaptic

POSTSYNAPTIC

each presympathetic fiber synapses with 30 or more postsympathetic fibers

40

function of postsynaptic sympathetic fibers

stimulate contraction of blood vessels and arrector muscles associated with hairs
and cause sweating

41

sympathetic innervation to the heart and lungs
cardiopulmonary splanchnic nerve

postganglionic
sympathetic
T1-5

the postganglionic cell body for these is and EXCEPTION!!! b/c it actually synapses in the sympathetic chain and not out in prevertebral ganglia

42

vagus

presynaptic parasympathetic nerve fibers exit via this nerve and synapse in plexuses on the surface of organs or arteries (unnamed ganglionics)

43

pelvic splanchnics

these arise at spinal cord levels S2-S4

part of the sacral outflow of parasympathetic system

Exception to the rule that parasympathetic fibers are characteristically not found in spinal nerves!!!

PS=PS

preganglionic

44

prevertebral
pre aortic
collateral

GANGLIA

sit in front of aorta

this is where splanchnic nerves come to synapse

45

greater splanchnic nerve

T5-T9 (thorax)

goes through diaphragm--> synapse on celiac ganglion

liver, stomach, spleen, pancreas, duodenum

sympathetic
preganglionic

46

lesser splanchnic nerve

T10-11 goes through diaphragm

kidney and gonad

sympathetic

47

least splanchnic nerve

T12

kidney

sympathetic

48

lumbar splanchnic nerve

L1-L3

sympathetic

49

what are autonomic plexuses?

sympathetic and parasympathetic fibers travel together as plexuses on the surface of arterial blood vessels

only the postganglionic parasympathetic fiber does not exist within these plexuses as it can only be found within the walls of the organs they are destined to innervate

50

although parasympathetic fibers may travel on the surface of arteries....

THEY DO NOT INNERVATE THEM

51

in which division of the ANS is the ratio of postganglionic to preganglionic fibers much greater?

the sympathetic division and this is because of the more "global" effect of the sympathetic NS versus the more "local" effect of the parasympathetic NS

52

what is the neurotransmitter for the synapse of the preganglionic fiber with the postganglionic neuron in para and sympathetic NS?

Ach

53

what is the neurotransmitter for the synapse of postganglionic fibers on the effector organs for parasympathetic vs sympathetic

parasympathetic --> Ach


sympathetic --> norepinephrine (NE)

54

two types of visceral pain

acute sharp

dull or nauseous

55

what causes dull nauseous pain

distention of a hollow organ

parasympathetic nervous system

not very well localized due to their cranio-sacral innervation

56

what causes acute or sharp pain?

registered by visceral afferent fibers which return to the spinal cord along routes which parallel the sympathetic system

57

why is acute pain well localized?

since preganglionic sympathetic fibers arise from specific segments of the spinal cord and travel within all spinal nerves, pain fibers which parallel them enter the spinal cord at the exact same spinal levels as the origin of sympathetic EFFERENT fibers

58

viscera and dermatomes?

viscera are segmentally innervated by branches of spinal nerves that correlate to the dermatomes

AND Afferent fibers for pain travel with the sympathetic visceral motor system. THEREFORE dermatomes which are implicated in referred pain syndromes are limited to levels T1-L2

59

what happens when disease or infection occur internally over a protracted period of time?

stimulate ascending tract neurons to the point that their stimulation is perceived

the brain incorrectly thinks this pain is coming from the surface of the body at the same spinal level as the incoming visceral afferents
THIS IS THE BASIS OF REFERRED PAIN

60

what can visceral afferent fibers entering the spinal cord synapse on? and what will be the outcome of this synapse


basis for viscerosomatic reflex

can synapse on interneurons that synapse on cells of the lateral and ventral horns

LOTS OF NEUROTRANSMITTER bathing these nerves so they are excitable and fire automatically

these interneurons can then stimulate two things:
1. preganglionic sympathetic nerve fibers causing vascular smooth muscle contraction

2. ventral motor horn cell stimulation causing contraction of paraspinal musculature

61

viscerosomatic reflex

visceral afferent stimulation resulting in somatic responses

can include change in the character of the connective tissue due to reduced vascular flow (increased sympathetic tone)

or can include tightness due to increased somatic muscular tone and referred pain

62

important note about visceral afferents and splanchnics...

visceral afferents that parallel sympathetic splanchnic nerves return to the identical spinal cord levels of visceral efferent innervation

63

angina pectoris

T1-4,5

64

facilitated segment

a segment of spinal cord that has facilitated somatic changes due to visceral input


areas of SD those that display the effects of vescerosoatic reflexes can lead to the identification and localization of visceral disease

65

specific osteopathic manipulation applied to areas of somatic dysfunction can do what?

through stimulation of somatic afferent fibers and spinal interneurons can help to tone down the effects of visceral afferents stimulated by underlying disease processes