3 Flashcards

1
Q

General Model of SNS:

A
  1. Motor output to the sympathetic nervous system descends from the brain OR input from afferents (from the body) synapses on neurons in the intermediolateral cell column (gray matter) - Located from T1 – L3
  2. SNS neurons send efferent axons through the white rami communicantes to a paravertebral ganglion
  3. Within the paravertebral ganglion, the axon can:
    - Option 1: Synapse within the paravertebral ganglion at that spinal level
    - Option 2: Continue to another paravertebral ganglion at a different spinal level and synapse there
    - Option 3: Pass through the paravertebral ganglion and continue to a prevertebral ganglion (through a splanchnic nerve) and synapse there
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2
Q

Solid lines = efferents from spinal cord to _________

A

1st ganglion
- pre-gangionic fibre

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3
Q

Dotted lines = efferents from gangion to ___

A

target organ
- post-ganglionic fibre

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4
Q

Where is the intermediolateral horn/column found?

A

Found in lamina VII of the thoracic and upper lumbar spinal cord

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5
Q

T/F: The descending pathways that influence neurons in intermediolateral horn/column are diffuse and hard to distinguish

A

True

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6
Q

Reflex pathways from afferents also impact the activity of neurons in which column?

A

intermediolateral horn/column

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7
Q

Option 1: Neuron in the intermediolateral horn (pre-ganglionic neuron) –> synapses on a neuron in the paravertebral ganglion at that __ spinal level

A

same

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8
Q

Option 1: Axon travels through the __ __ __, synapses on the post-ganglionic neuron

A

white rami communicantes

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9
Q

T/F: White rami communicantes are myelinated

A

True

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10
Q

Option 1: The postganglionic neuron sends efferents out to __ __

A

visceral organs

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11
Q

T/F: Gray rami communicantes are myelinated

A

False, unmyelinated

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12
Q

Option 1: Gray rami communicantes (unmyelinated fibres) join the __ __

A

spinal nerve

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13
Q

What are sympathetic inputs of option 1 of the SNS?

A
  • skin, blood vessels, heart, and lungs at that spinal level
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14
Q

Option 2: Where do the cervical ganglia recieve fibers from?

A

Upper thoracic intermediolateral horn:
- Superior cervical ganglion – around the level of C1 – C4
- Middle cervical ganglion C5-C6
- Inferior cervical ganglion C7-C8

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14
Q

Option 2: Neuron in the intermediolateral horn (pre-ganglionic neuron) –> synapses on a neuron in a paravertebral ganglion at a __ spinal level

A

different

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15
Q

Option 2: The inferior cervical ganglion fuses with fibres from the first thoracic ganglion to form the __ __

A

stellate ganglion

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16
Q

Option 2: Superior cervical ganglion – SNS input to the __ __

A

cranial nerves

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17
Q

Option 2: nerves travel along blood vessels and often join the parasympathetic fibres of __ __

A

cranial nerves

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18
Q

Option 2: Which cranial nerves does the superior cervical ganglion house?

A

CNs III, VIII, IX, X

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19
Q

Option 2: Middle + stellate – SNS input to:

A
  • heart
  • trachea, bronchi, bronchioles
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20
Q

The __ and __ receive inputs from “Option 1” and “Option 2” gray ramii, forming web-like cardiac and pulmonary plexuses that innervate these structures

A

heart; lungs

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21
Q

Option 2: Long ciliary nerves –> SNS input to pupil causing? Accompanies by?

A
  • pupillary dilation
  • accompany short ciliary nerves (CN III)
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22
Q

Option 2: T/F: SNS input tends to make tears, saliva less “watery”, more “mucus-y”

A

True

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23
Q

Option 2: The SNS inputs tend to accompany the cranial nerves at some point along their course, which cranial nerves?

A

CN VII, IX

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24
Q

Option 3: Neuron in the intermediolateral horn –> passes through the paravertebral ganglion (no synapse) –> synapses on a ___ __

A

pre-vertebral ganglion

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25
Q

Option 3: The __ __ form nerves on the way to the prevertebral ganglion

A

white ramii

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26
Q

Option 3: greater splanchnic nerve –> __ __ (T5 – T9)

A

celiac ganglion

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27
Q

Option 3: lesser splanchnic nerve –> __ __ __, __ __ (T10 – T11)

A

superior mesenteric ganglia, aorticorenal ganglia

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28
Q

least splanchnic nerve –> __ __ (T12)

A

renal plexus/ganglia

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29
Q

lumbar & sacral splanchnic nerves –> __ __ __, plexuses to pelvic and lower abdominal organs (L1 – L2)

A

inferior mesenteric ganglia

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30
Q

Option 3: What is the celiac ganglion responsible for?

A

pancreas, liver

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31
Q

Option 3: What is the aorticorenal ganglia responsible for?

A
  • kidney
  • gonad
  • suprarenal gland
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32
Q

Option 3: What is the superior mesenteric ganglion responsible for?

A
  • ascending colon
  • transverse colon
  • small intestine
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33
Q

Option 3: What is the inferior mesenteric ganglion responsible for?

A
  • descending colon
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34
Q

Compare and contrast SNS & PNS

A

Sympathetic nervous system
- short pre-ganglionic fibres, longer post-ganglionic fibres
- Neuronal cell bodies in the intermediolateral horn of T1 – L3
- Ganglia can be paravertebral or prevertebral
- Pre-ganglionic fibres can be white rami communicantes from the spinal cord or splanchnic nerves

Parasympathetic nervous system
- Long pre-ganglionic fibres, short post-ganglionic fibres
- Neuronal cell bodies in the brainstem (cranial nerve nuclei) or sacral spinal levels
- No prevertebral or postvertebral ganglia

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35
Q

T/F: Parasympathetic nervous system is cranial nerve and sympathetic nervous system is spinal nerves (but can combine with cranial nerves)

A

True

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36
Q

Edinger-Westphal nucleus (midbrain) –> ciliary ganglion –> causing pupillary constriction

A

CN III

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37
Q

Superior salvitory nucleus (pons) –> sphenopalatine –> lacrimal gland, nasal mucous secretions

38
Q

superior salivatory nucleus (pons) –> submandibular ganglion –> sublingual, submaxillary salivary glands

39
Q

inferior salivatory nucleus (medulla) –> otic ganglion –> parotid salivary glands

40
Q

Salivary & lacrimal secretion is mainly under control of which nervous system?

A

parasympathetic nervous system control

41
Q

T/F: PNS causes more saliva, more watery, more digestive enzymes

42
Q

T/F: SNS causes less fluid, more “sticky”

43
Q

What is the cranial nerve responsible for most of parasympathetic nervous output?

44
Q

What nucleus is associated with the vagus nerve?

A

dorsal motor nucleus of the vagus

45
Q

What is the pathway of the vagus nerve?

A
  • Longest course of any cranial nerve – leaves through jugular foramen and descends alongside the carotid arteries
  • Forms anterior and posterior trunks at the stomach and divides to supply plexuses in the abdominal cavity, all the way to the left (distal) colon
46
Q

Where are the bodies of the parasympathetic sacral efferents found?

47
Q

What do the parasympathetic sacral efferents travel with?

A

pelvic splanchnic nerves

48
Q

What does the parasympathetic sacral efferent supply?

A
  • rectum
  • bladder
  • male & female reproductive organs
49
Q

Fill in the blocked out spots

A

intermediolateral column, T1-L3

pre vertebral & paravertebral

brainstem nuclei & sacral segments

small ganglia in walls of viscera

50
Q

What is the main neuro-transmitter & main receptor of SNS preganglionic?

A
  • acetylcholine
  • nicotinic
51
Q

What is the main neuro-transmitter & main receptor of SNS postganglionic?

A
  • norepinpehrine (+ epinphrine in adrenal medulla)
  • adrenergic, alpha + beta
52
Q

What is the main neurotransmitter & main receptor of PaNS preganglionic?

A
  • acetylcholine
  • nicotinic
53
Q

What is the main neurotransmitter & main receptor of PaNS postganglionic?

A
  • acetylcholine
  • muscarinic (acetylcholine)
54
Q

What are exceptions to SNS postganglionic neurotransmission?

A
  • Acetylcholine in skin
  • Adrenal glands don’t have post-ganglionic innervation… they “are” the ganglion
55
Q

When is acetylcholine used in SNS postganglionic neurotransmission?

A
  • sweat glands (muscarinic)
56
Q

Where does the parasympathetic nervous system have impact on blood vessels?

A
  • the GI system
  • the reproductive system
57
Q

Where is acetylcholine synthesized & stored?

A

Acetylcholine is synthesized in presynaptic nerve terminals and then stored in vesicles

  • Reaction:
    Acetyl-CoA + Choline —————-> Acetylcholine
    Enzyme: choline acetyltransferase
58
Q

After acetylcholine is secreted into the synapse it is degraded by what?

A

acetylcholinesterase

59
Q

What is acetylcholine degraded to?

A

acetate and choline (choline is taken back up into the presynaptic terminal)

60
Q

Where is acetylcholinesterase distributed?

A

Acetylcholinesterase is widely distributed in connective tissue throughout the body and in the synapse of cholinergic terminals

61
Q

How is norepinephrine synthesized?

A

Outside the vesicle:
- Tyrosine ———————> Dopa (hydroxylation)
- Dopa ————————-> Dopamine (decarboxylation)

Then, dopamine is transported into the synaptic vesicle:
- Dopamine ——————-> Norepinephrine (hydroxylation)

In the adrenal medulla, most norepinephrine is converted into epinephrine through methylation (in the vesicle)
- Norepinephrine ————> Epinephrine (methylation)

62
Q

hormones made by adrenal glands

A

caetcholamines

63
Q

__-__% of secreted norepinephrine is taken up again into the presynaptic terminal

64
Q

How is epinephrine taken back up?

A

secreted into the bloodstream by the adrenal medulla (endocrine)

65
Q

__ can be broken down by monoamine oxidase near the synapse and catechol-O-methyl-transferase (COMT)

A

Norepinephrine

68
Q

Both the parasympathetic (__) and sympathetic (__) outputs are important for pupillay size

However, focusing the lens is mostly under control of the __ system

A

constriction; dilation; parasympathetic

69
Q

Nasal, lacrimal, salivary, gastrointestinal glands:
Strongly stimulated by __ activity – lots of watery secretions that are rich in enzymes (when enzymes apply)

Glandular secretion can also be stimulated by the __ – less watery, therefore usually lower rate of secretion

The glands of the intestines are less controlled by the ___, more by the food in the lumen of the gut

A

parasympathetic; sympathetic; autonomic NS

70
Q

Sweat glands: stimulated by the __ – however, the neurotransmitter secreted is __

A

sympathetic nervous system; acetylcholine

71
Q

Blood vessels:
__ nervous system – vasoconstriction in most vascular beds – mediated by alpha-1 receptors - Vasodilation in others mediated by __ in skeletal muscles, heart, liver

__ nervous system – very limited effect on any blood vessels outside the GI tract and reproductive organs

A

Sympathetic; beta-2 receptors; Parasympathetic

72
Q

Heart:
__ nervous system – beta-1 receptors increase contractility (basically, force of contraction) and heart rate –> increased cardiac output

__ – muscarinic receptors decrease heart rate but have a small (negative) influence on contractility

A

Sympathetic; Parasympathetic

73
Q

Glucose metabolism:
No role for the __ nervous system

Gluconeogenesis, glycogenolysis, hyperglycemia with __ nervous system stimulation

A

parasympathetic; sympathetic

74
Q

The parasympathetic nervous system usually causes __, __ responses

A

specific localized

75
Q

The sympathetic nervous system can participate in specific, localized responses as well – the usual day-to-day function of the SNS + overwhelmingly activated (mass discharge) to accomplish the “__ _ __” response

A

fight or flight

76
Q

Major reflexes include:
Baroreceptor reflex
- __ – baroreceptors from CNs IX and X
- __ – parasympathetic and sympathetic  CN X, thoracic plexus

GI reflexes mediated by sensing food (whether sight/taste/smell or presence of food/secretions in the lumen)
- __ – visceral receptors from CN X
- __ – CN X

Micturition (urination) reflex
- afferents & efferents at the level of the __ __ __

A

afferent; efferent

afferent; efferent

sacral spinal cord

77
Q

__ __ __ in the medulla receives input from the afferents, sends output to a wide variety of other brain areas

A

Nucleus tractus solitarius

78
Q

Prevention of storage in the NT vesicle
Reserpine – blocks VMAT –> depletion of catecholamines, increase or decrease in catecholamine transmission?

79
Q

Non-vesicle-mediated “leakage” of neurotransmitter from the presynaptic terminal
Amphetamine, tyramine, increase or decrease in catecholamine transmission?

80
Q

Inhibition of reuptake at the presynaptic terminal
Cocaine, selective norepinephrine reuptake inhibitors (i.e. Effexor)
Increase or decrease in catecholamine transmission?

81
Q

Inhibition of NT degradation
Mono-amine oxidase inhibitors (tranylcypromine)
Increase or decrease in catecholamine transmission?

82
Q

Inhibition of NT release due to auto-receptor activation
Clonidine thought to be a major example
Increase or decrease in catecholamine transmission?

83
Q

a substance that activates a receptor when it binds to it

84
Q

a substance that binds to a receptor but doesn’t activate it fully

A

partial agonist

85
Q

a substance that inactivates a receptor or enzyme when it binds to it

A

antagonist

86
Q

T/F: Antagonist can be reversible & irreversible

87
Q

Alpha and beta receptors have different __ for different agonists and antagonists

A

affinities

88
Q

beta receptors have a high affinity for __, but alpha receptors have a negligible affinity. __ is therefore a selective beta-agonist

A

isoproterenol

89
Q

Beta-1 receptors have a high affinity for __, but beta-2 receptors don’t. __ is therefore a selective beta-1 antagonist

A

metoprolol

90
Q

Phenylephrine
- Selective agonist for __ receptors
- Main indication is as an over-the-counter __ - Causes vasoconstriction and decreased secretions from the nasal mucosa
- Can also be used IV (emergently) to increase __ __

A
  • alpha-1
  • decongestant
  • blood pressure
91
Q

Clonidine
- Selective __ agonist - Acts on presynaptic terminals to reduce __ transmission in the central nervous system
- Main indication is as an __ – reduction of sympathetic nervous system activity

A
  • alpha-2
  • adrenergic
  • antihypertensive
92
Q

Isoproteronol – activates __ and __ receptors
Dobutamine – activates __ receptors with less __ receptor effect

Both increase cardiac output… but dobutamine will increase blood pressure the most
Why would this be?

A

beta-1; beta-2

beta-1; beta-2

Increase HR –> increases contractility –> increases SV

93
Q

Albuterol, salbutamol are inhaled selective __ agonists

Activate __ receptors in the bronchioles

A

beta-2; beta-2