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Flashcards in Autonomic Nervous System Deck (63):
1

What are the 3 major divisions of the autonomic nervous system?

- Sympathetic
- Parasympathetic
- Enteric

2

Where is the sympathetic nervous system located?

- Thoracic spinal cord

3

Where is the parasympathetic nervous system located?

- Cranial nerves
- Sacral spinal cord

4

Where is the enteric nervous system located?

- In the gut

5

What type of system is the enteric nervous system?

- Efferent effector

6

What 2 structures control the enteric nervous system?

- Hypothalamus
- Solitary nucleus in brain stem

7

What are the 4 methods by which preganglionic fibers of the sympathetic nervous system project?

- Enter chain ganglion, and synapse on post ganglionic neurons
- Enter chain, and ascend to another level before synapsing
- Enter chain and descend to another level before synapsing
- Go through chain, and join splanchnic nerves to synapse on prevertebral ganglia

8

Where do the preganglionic fibers of the sympathetic nervous system originate from?

- T1 - L1 from beta cells in lateral horn (intermediolateralis - lamina 7)

9

What do preganglionic fibers of the sympathetic nervous system do before synapsing on post ganglionic neurons?

- Diverge

10

Do sympathetic or parasympathetic neurons synapse closer to the spinal cord?

Sympathetic

11

What is the ratio of preganglionic to postganglionic fibers in the sympathetic nervous system?

1:10

12

What fiber type comprosises less than 20 % of the total visceral fibers in the sympathetic nervous system?

- General Visceral Afferent

13

What neurotransmitter is released by preganglionic and postganglionic fibers in the sympathetic nervous system?

Pre: ACh
Post: NE

14

Are pre or postgangionic fibers heavily myelinated in the sympathetic nervous system?

- Postganglionic

15

Are pre or postganglionic fibers lightly myelinated in the sympathetic nervous system?

- Preganglionic

16

What type of stimuli is brough by stimulation of GVA fibers int he sympathetic nervous system?

- Noxious

17

What type of cells are the pre-ganglionic fibers of the sympathetic nervous system?

- Beta

18

How do the beta cells of the sympathetic nervous system exit the spinal cord?

- Leave ventral horn through ventral route, and enter chain ganglion to synapse

19

What type of sympathetic fiber does not synapse within the chain?

Visceral fibers

20

What cranial nerves make up a portion of the parasympathetic nervous system?

3, 7, 9, 10

21

Which sacral segments make up a portion of the parasympathetic nervous system?

S2 - S4

22

Where are the post ganglionic neurons of the parasympathetic nervous system located?

- In the structures that they innervate

23

How are general visceral afferent fibers different in the parasympathetic nervous system compared to the sympathetic?

- More abdundant and innocuous

24

What neurotransmitters are released by the preganglionic and postganglionic fibers of the parasympathetic nervous system?

Pre: ACh
Poster: ACh

25

What is the ratio of pre-ganglionic to post-ganglionic fibers in the parasympathetic nervous system?

1:3

26

What type of nerve fiber is not found below L3 or above T1?

- General visceral efferents

27

What 3 structures are innervated by the enteric nervous system?

- GI tract
- Pancreas
- Gall bladder

28

Does the enteric nervous system function autonomously?

Yes, but it can be regulated by the sympathetic and parasympathetic nervous systems

29

What is a plexus?

- Meshwork of ganglia and interconnecting nerve fibers located between the various layers of muscle and endothelium

30

Where is the myenteric plexus found?

Between external longitudinal and circular smooth muscle layers

31

Where is the submucosal plexus found?

- Within the connective tissue of the submocusa between the circular muscles and mucosa

32

What is another name for vasodepressor syncope?

Neurogenic shock

33

What is neurogenic shock?

- Vasodilation of muscles diverts blood to muscles, causing a lack of blood flow to the brain
- Caused by strong emotions that drive sympathetic nervous system
- Syncope occurs

34

What are the 3 general types of innervation to the bladder?

- Parasympathetic
- Sympathetic
- Somatic

35

What 4 portions of the cortex have an influence on bladder innervation?

- Anterior cingulate cortex (ACC)
- Insula
- Pre-frontal cortex
- Hypothalamus

36

What tract sends information regarding bladder innervation to the cortex and periaquidcutal gray?

Lateral spinothalamic tract

37

What is the function of the periaqueductal gray?

- Stimulates activation of center 2 in the Pons

38

What is the function of center 2 in the Pons?

Stimulates the sympathetic nervous system, which:
- Relaxes the detrussor muscle through inhibition of the parasympathetic, and inhibition directly to the muscle
- Stimulates the internal urethral sphincter

Also inhibits center 1

39

What is the function of center 1 in the Pons?

Stimulates the parasympathetic nervous system, which:
- Stimulates contraction of the destrussor muscle

40

What spinal cord segments work with center 1?

S2 - S4

41

What spinal cord segments work with center 2?

T1 - L1

42

What nuclei work with center 2?

- Onuf nuclei

43

What is the function of the somatic nervous system in the bladder?

- Stimulates external uretheral sphincter

44

What is the term for reflexive bladder pathology?

- Uninhibited reflex neurogenic bladder

45

What is uninhibited reflex neurogenic bladder?

- Voluntary control of filling and emptying of bladder is lost
- No concious perception of bladder filling or emptying
- Bladder fills and empties reflexively

46

At what level do bladder reflexes occur?

Pontine level

47

What type of lesion will cause uninhibited reflex neurogenic bladder?

- Bilateral frontal lobe lesion

48

How can uninhibited reflex neurogenic bladder be controlled?

With diet

49

Is uninhibited reflex neurogenic bladder an Upper or Lower Motor Neuron lesion?

Upper

50

What are the symptoms of Automatic Bladder?

- Micturition control is lost
- Bladder empties incompletely

51

Why does the bladder empty incompletely in Automatic Bladder?

- Reflex pathways that trigger pontine micturition is gone
- Each time the bladder is stretched, it empties (not when completely stretched)

52

What is the location of a lesion that will cause automatic bladder?

- Bilateral spinal cord lesion above sacral levels

53

What systemic changes can occur in Automatic Bladder?

- Blood pressure
- heart changes

54

What are major symptoms of Non-Reflexive Bladder?

- Bladder fills to capacity and overflows --> dribbling
- Bladder wall is flaccid

55

What is the cause of non-reflexive bladder?

- Sacral reflex arc lesioned

56

Where is the location of the lesion in non-reflexive bladder?

- Bilateral lesion to sacral cord or pelvic nerves

57

What renal complication may arise from non-reflexive bladder?

- Infection

58

What center controls the defecation reflex?

- Hypothalamic autonomic center

59

What 2 structures make up the hypothalamic autonomic centre?

- Mesencephalon pons
- Dorsal motor nucleus

60

What 2 parasympathetic nerves stimulate defecation?

- Pudendal nerve
- Vagus nerve

61

What sympathetic nerve inhibits defecation?

- Hypogastric nerves

62

What spinal segments facilitate defecation?

S2 - S4

63

What spinal nerve roots inhibit defecation?

L1 - L3