24.3 Autonomic nervous system Flashcards Preview

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Flashcards in 24.3 Autonomic nervous system Deck (67):
1

What are visceral change the ANS can alter rapidly and intensly?

1. HR can double in 3-5 seconds
2. double arterial pressure
3. initiate sweating

2

What is the best way to describe the pathways of the ANS?

2 series of neurons. preganglionic and postganglionic neurons

3

Describe the features of a preganglionic neuron.

1. CNS contains the cell bodies
2. myelinated axons
3. Ach is the neurotransmitter

4

Whate are unique features of the postganglionic neurons?

1. cell bodies locate in peripheral ganglia
2. non-myelinatd
3.parasympathetics=Ach
sympathetics= norepinephrine

5

Where are large numbers of mitochondria generally found in the ANS pathways to organs?

in terminal fibers with enlarged varicosities

6

Where do preganglionic neurons of the sympathetic system lie?

1. T1-L2 intermediolateral horn
2 synapse in paravertebral chain

7

What fibers form 8% of fibers in teh average nerve?

postganglionic sympathetic fibers

8

What kind of fibers are postganglionic sympathetic fibers?

type C fibers (unmyelinated) that control blood vessel, sweat glands and piloerector muscles

9

What nerve fibers pass through the gray rami?

postganglionic sympathetic fibers

10

What are the 12 thoracic ganglia pairs normally referred to?

stellate ganglion. with first pair fused with inferior cervical ganglion

11

What are the components of the cervical ganglia?

1. superior
2. middle
3. inferior

12

What nerves supply the preganglionic sympathetic supply to the thoracic viscera?

T1-T5

13

What nerves supply the postganglionic sympathetics to the thoracic viscera?

1. superior, middle, inferior cervical ganglion
2. T1-T5 paravertebral ganglia

14

What is the function of the cardiopulmonary splanchnic nerves that travel all by themselves?

1. dilate coronary artery
2. increase heart rate
3. bronchodilation

15

What comprise splanchnic nerves?

preganglionic fibers and visceral sensory fibers

16

What do splanchnic nerves supply?

abdominal viscera

17

Where do splanchnic nerves synapse?

prevertebral ganglia

18

What nerves form the greater splanchnic nerves?

1. T5-T9
2. synapse in the celiac region

19

What nerves form the middle splanchnic nerves?

T10-T11, synapse in superior mesenteric ganglion

20

What nerves form the least splanchnic nerves?

T12, synapse in the aorticorenal ganglion

21

The adrenal medulla releases 80% epinephrine and 20% norepinephrine via the______________system.

sympathetic

22

Effects of circulating norepinephrine?

1. blood vessel constriction
2. increase HR
3. inhibit GI
4. dilate pupils

23

What are the secretory cells of teh adrenal medulla?

innervated by postganglionic neurons with rudimentary fibers that secrete epinephrine and norepinephrine

24

Which hormone is more effective in elevating arterial pressure?

norepinephrine

25

Which hormone increases cardiac output most effectively?

epinephrine

26

Which hormone affects metabolism most effectively by increasing rate 5-10 times?

epinephrine more effective than norepinephrine

27

Where is 75 % of all parasympathetic fibers contained?

1) vagus nerve CNX

28

Where are postganglionic parasympathetic fibers located?

in the wall of the organ and use Ach as NT

29

What 4 cranial nerves contain parasympathetics?

1. III
2. VII
3. IX
4. X

30

What are the funcitons of the oculomotor nerve?

1.supplies extrinsic eye muscles and levator palpebra superioris

31

What is the path of oculomotor nerve preganglionic parasympathetic nerve?

1. edinger-westphal nucleus to ciliary ganglion

32

WHat is the path of oculomotor nerve postganglionic parasympathetics?

ciliary ganglion to sphincter pupillae muscle

33

What are the primary funcitons of the Facial Nerve?

1. innervate muscles of facial expression
2. provide taste to the anterior 2/3 of tongue

34

What are the parasympathetic functions of the Facial Nerve?

1.preganglionic: superior salivary and lacrimal nuclei to the submandibular/sublingual ganglia
2. postganglionic: to lacrimal gland, submandibular/sublingual gland, mucous glands of mouth and nose

35

What are functions of the glossopharyneal nerve?

1. general sensation and sensation from posterio 1/3 of tongue

36

What are the parasympathetic functions of the glossopharyngeal nerve?

1. preganglionic: from inferior salivary nucleus to otic ganglion
2. postganglionic: to parotid gland

37

What are the functions of teh vagus nerve?

1. motor supply to 4th and 5th pharyngeal arches. swallowing and speaking as well.

38

What is the major parasympathetic supply to thoracic and abdominal organs?

vagus nerve

39

WHat is the pathways of the parasympathetics for the vagus nerve?

1. pre: from dorsal motor nucleus
2. post: myenteric plexus of wall of gut tube to left colic flexure

40

What is teh course of teh vagus nerve through the body?

1. parallels and innervates esophagus
2. posterior to root of lung on each side
3. follows esophagus through esophageal hiatus
4. is now gastric nerve
5. supplies viscera in thoracic cavity

41

What are the branches of the vagus nerve?

1. cardiac=> cardiac plexus
2. pulmonary=> pulmonary plexus
3. esophageal=> esophageal plexus

42

Which nerve wraps around teh arch of the aorta to the left of the ligamentum arteriosum?

left recurrent laryngeal nerve form the left vagus branch

43

Which nerve arise in the neck and not the thorax? Vagus nerve branch

1. right recurrent laryngeal nerve from the right vagus nerve

44

What enzyme helps form acetylcholine?

choline acetyl-transferase

45

What enzyme helps degrade acetylcholine?

acetylcholinesterase

46

What is the process to form norepinephrine?

1. hydroxylate tyrosine to dopa
2. decarboxylate dopa to dopamine
3. transport dopamine to vesicles
4. hydroxylate dopamine to norepinephrine
5. 80% of norepinephrine is methylated to form epinephrine

47

How can norepinephrine be removed?

1. monamine oxidase
2. catechol-O-methly transferase
3. reuptake
4. diffusion

48

Where are muscarinic acetylcholine receptors found?

1. on all effector cells stimulated by postganglionic cholinergic neurons

49

Where are nicotinic acetylcholine receptors found?

1. autonomic ganglia at synapse between pre-/postganglionic neurons
2. on neuromuscular junction in skeletal muscles

50

Stimulation of beta 1 adrenergic receptors cause what response?

1. cardioacceleration
2. increase myocardial strength
3. lipolysis

51

Stimulation of beta 2 adrenergic receptos cause what response?

1. vasodilation, intestinal/uterine relax
2.bronchodilation, calorigenesis
3. glycogenolysis

52

What does stimulation of beta 3 adrenergic receptors cause?

1. thermogenesis

53

What are the sympathomimetic drugs?

1. norepi/epinephrine
2. methoxamine
3. phenylephrine
4. isoproterenol
5.albuterol

54

Which drugs cause release of norepinephrine?

1. ephedrine
2. tyramine
3. amphetamine

55

What does reserpine do?

1. block adrenergic activity
2. block norepinephrine synthesis/storage

56

What does guanethidine do?

1.block adrenergic activity
2. prevent release of norepinephrine

57

What does phenoxybenzamine/phentolamine do?

1. block adrenergic activity
2. blocks sympathetic alpha receptors

58

What does propranolol do?

1. blocks adrenergic activity
2. blocks sympathetic beta 1 and beta 2 receptors

59

What does metoprolol do?

1. blocks adrenergic activity
2. blocks sympathetic beta 1 receptors

60

What does hexamethonium do?

1. blocks adrenergic activity
2. stops transmission through autonomic ganglia

61

What are parasympathomimetic drugs and what effect do they have?

1. pilocarpine and methacoline
2. act on muscarinic receptors and are not readily removd by acetylcholinesterases

62

What drugs inhibit the activity of acetylcholinesterase?

1. neostigmine
2. pyridostigmine
3. ambenonium

63

What drugs block the cholinergic activity?

1. atropine
2. homatropine
3. scopolamine

64

Which system is responsible for causing pupil dilation?

1. sympathetic

65

Which system controls pupil constriction and lens focusing?

1. parasympathetic

66

Glands controlled by the sympathetic system elicits what responses?

1. secretion of large amount of sweat. via cholinergic fibers.
2. technically are parasympathetic fibers distributed via sympathetics

67

Glands controlled by the parasympathetic system are able to elicit what kind of response?

1.stimulate lacrimal, nasal, salivary, GI glands of upper tract
* lower GI glands stimulated via enteric system