Musculoskeletal - 521 - (1-3) Dr. Fernandez Test Flashcards Preview

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Flashcards in Musculoskeletal - 521 - (1-3) Dr. Fernandez Test Deck (173)
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1
Q

What are the two sensory divisions of the Nervous System?

A

Visceral and Somatic

2
Q

The autonomic nervous system is ALWAYS

A

Motor

3
Q

The somatic motor division of the PNS innervates…

A

Skeletal Muscle

4
Q

What percentage of interneurons comprise the human nervous system?

A

90%

5
Q

How long can a neuron live?

A

Whole life

6
Q

What are some exceptions to neurons being amitotic?

A

Olfactory neurons - some areas of the brain.

7
Q

What are Nissl bodies?

A

They are dark areas associated with Ribosomes and thus a lot of protein production

8
Q

Is a Schwann cell a glial cell?

A

Yes - specialized type

9
Q

What histologically indicated an axon hillock?

A

No Nissl bodies.

10
Q

What is another name for Nissl Bodies?

A

Chromatophilic substance

11
Q

Are dendrites myelinated?

A

No

12
Q

Can an axon be branched?

A

Yes

13
Q

What is another name for the axon hillock?

A

Initial Segment

14
Q

Which is smoother, the axon or the dendrites?

A

Axon

15
Q

What is the most common type of neuron morphology?

A

Multipolar

16
Q

Where are Bipolar neurons found?

A

Olfactory and Retina

17
Q

Where are unipolar neurons found?

A

Dorsal root ganglia

18
Q

What are the two main processes that form off a unipolar neuron?

A
Central process (goes to spinal cord) and 
peripheral process
19
Q

A neuron that has only dendrites, in which the soma acts as an axon, is called…

A

Anaxonic

20
Q

What percentage do glial cells make up in the CNS?

A

90% (50% by volume)

21
Q

Name 4 kinds of CNS glia and 1 PNS glia.

A

Astrocyte, oligodendrocyte, microglia, ependymal

Schwann Cells

22
Q

What is the apparatus that separates neurons from capillaries and what cell does it come from?

A

Perivascular feet.

Astrocyte (remember - a glial cell)

23
Q

What cell covers axons in the CNS?

A

Oligodendrocytes

24
Q

What cells are simple columnar ciliated?

A

Ependymal cells

25
Q

Which glial cell is responsible for CNS immune activity?

A

Microglia

26
Q

Do oligodendrocytes myelinate axons?

A

Negative ghost rider. They cover axons in the CNS

27
Q

How many nerve fibers can an oligodendrocyte wrap?

How many can a Schwann cell wrap?

A

Many

One

28
Q

Can an oligodendrocyte form a myelin sheath?

A

Yes - they can wrap multiple times

29
Q

When developmentally does myelination stop?

A

adulthood

30
Q

What is the lipid makeup of myelin?

A

80%

31
Q

Are all axons myelinated?

A

No. But all are wrapped

32
Q

What is the gap between Schwann cells called?

A

Node of Ranvier

33
Q

If an axon is wrapped once it is…

If an axon is wrapped many times it is…

A

Unmyelinated

myelinated

34
Q

Can myelination occur in the adult brain?

A

You better freakin hope so.
The brain does this continually to form new skills (especially motor) and acquire new memories
New myelination is KEY for learning and pathway reinforcement

35
Q

Explain the difference between electrical potential and current.

A

potential - difference in charge

current - movement of said charge

36
Q

What is the Na/K pump ratio?

A

3 Na OUT for 2 K IN

37
Q

Why does nerve tissue have such a high use of ATP?

A

Na/K pumps run continuously and require one ATP per cycle

38
Q

K leak channels accomplish what?

A

More negative charge outside cell

39
Q

Na leak channel accomplish what?

A

Prevent hyperpolarization - not many of these

40
Q

Why does the Axon Hillock have such high density of voltage gated channels?

A

Trigger zone for initiating action potential

500 per square micron

41
Q

What additional voltage gated channel is present at the terminal bouton?

A

Ca++

42
Q

What can initiate a local potential?

A

ligands (hormones or neurotransmitters)

light, temperature, mechanical disturbance

43
Q

Local potentials are (3 things)…

A

Graded, Decremental, and Reversible

44
Q

What are 2 types of postsynaptic potentials?

A

Excitatory (Na+ flows into cell)

Inhibitory (K+ leaves cell - hyperpolarization)

45
Q

Do neurotransmitters have to be exclusively excitatory or inhibitory?

A

No. Depends on receptors.

ACh excitatory in muscle cells and inhibitory in Cardiac tissue.

46
Q

Excitatory postsynaptic potentials make the membrane more…

A

positive

47
Q

Inhibitory postsynaptic potentials make the membrane more…

A

negative (hyperpolarized)

48
Q

What two things can directly cause hyperpolarization in an IPSP

A

Either Cl- flows in or K+ flows out

49
Q

What is the difference between temporal and spatial summation?

A

Temporal - signal comes from single source (many times)

Spatial - many sources of local potentials cause action potential

50
Q

A rapid spreading wave of depolarization and repolarization is called a….

A

Action Potential

51
Q

EPSP’s take the membrane______ to threshold

IPSP’s take the membrane ______ to threshold

A

Closer to

Further From

52
Q

Where is an important site of depolarization in the cell (after dendritic stimulis)?

A

Axon Hillock

53
Q

What is the peak charge of depolariztion?

A

+35 mV

54
Q

What ion depolarizes?

What ion repolarizes?

A

Na in

K out

55
Q

What does the slow action of K+ channels cause?

A

Hyperpolarization

56
Q

Is a nerve signal decrimental?

A

No - it’s like a fuse.

57
Q

What is the Refractory Period?

A

Short time after action potential fires when it is resistant to stimulation

58
Q

What is the Absolute refractory period

A

firing of potential

59
Q

What is the Relative refractory period

A

Hyperpolarized stage

60
Q

What two processes in the membrane are always on?

A
Na/K pump
leakage channels (Na in / K out)
61
Q

All healthy axons are covered by…

A

glial cells

62
Q

The larger the diameter of the axon…

A

The faster the signal

63
Q

What type of conduction occurs in myelinated axons?

A

Saltatory

64
Q

How fast do signals travel in unmyelinated axons?

A

1-4 mph

65
Q

How fast do signals travel in myelinated axons?

A

268 mph

66
Q

What causes saltatory action in myelinated axons?

A

Current flow pushes Na to next node, which opens channels, etc.

67
Q

The current flow along the inside of an axon in the area of a Schwann cell is…

A

Decremental

68
Q

What is the disease in which myelin sheaths deteriorate, thought to be an immune disorder triggered by a virus?

A

Multiple Sclerosis

69
Q

How many neurotransmitters are there?

A

Over 100 known

70
Q

name 3 types of synapses:

A

axodendritic, axosomatic, axoaxonic

71
Q

How many synapses are on a Purkinje cell?

A

100,000

72
Q

Describe neurotransmitter direct/indirect effects.

A

Neurotransmitter can either bind directly to ion channel and change its shape (Direct)
or, indirect via second messengers

73
Q

Terminal boutons have what additional voltage gated channels in their membrane?

A

Ca++

74
Q

What does Ca++ generally do in the terminal bouton?

A

Activates protein kinases > phosphorylates proteins > exocytose vesicles
i.e. Ca > Calmodulin > kinase activated > phosphorylates synapsin (which triggers exocytosis of neurotransmitter)

75
Q

How can repetitive firing change a synapse?

A

Increase number of receptors, increase membrane surface.

76
Q

What are the 4 major categories of neurotransmitter?

A

ACh
Amino Acids
Biogenic Amines (AA’s with COOH removed)
Neuropeptides

77
Q

What are two types of Biogenic Amines?

A

Catecholamines (epinepherine, dopamine)

Indolamines (serotonin, histamine)

78
Q

Chains of 2-40 AA’s that have long lasting effects are called what?

A

Neuropoptides

79
Q

What are some examples of neuropeptides?

A

opioids, somatostatin, substance P

80
Q

What is a typical second messenger?

A

cAMP

81
Q

Norepinepherine acts through what second messenger and is considered what type of synapse?

A

cAMP

Excitatory Adrenergic

82
Q

What happens to most neurotransmitter after release?

A

Reuptake by the presynaptic neuron ending (bulb/bouton)

83
Q

Describe an Inhibitory synapse?

A

GABA binds post-synapse and triggers Cl- channels.

This hyperpolarizes the cell

84
Q

Which wast product induces sleepiness in the brain and is temporarily counteracted by caffeine?

A

Adenosine

caffeine binds but does not activate adenosine receptors

85
Q

Where does the spinal cord begin and end?

A

Foramen Magnum to L1

86
Q

Why does the spinal cord only go to L1?

A

Vertebral column grows faster than spinal cord.

87
Q

What begins inferior to L1

A

Medullary cone

88
Q

What is the structure from L2 to S5 called?

A

Cauda Equina

89
Q

How many spinal nerves are there?

A

31 pairs

90
Q

Where are spinal taps (and spinal anasthesia) usually done and why?

A

L3- L4. There is more leeway in the cauda equina, and the nerve fibers here are less likely to be pierced

91
Q

What are spinal nerves that branch and merge called?

A

Plexus

92
Q

What are the 3 Mater (Meninges) of the Spinal cord and brain?

A

Dura
Arachnoid
Pia

93
Q

Where is an epidural given?

A

right outside the dura mater in fat/vasculature and anethetic diffuses from there

94
Q

What is between the dura mater and the csf?

A

Arachnoid.

simple squamous w/ loose CT mesh

95
Q

Where is the pia mater found?

A

On the surface of the spinal cord

96
Q

Are the meninges sensitive to pain?

A

Extremely

while brain is not

97
Q

CSF is found in the…

A

Subarachnoid space

98
Q

What does the fat in the epidural space resemble?

A

Hypodermis

99
Q

From superficial to deep, what are the layers of the meninges?

A

Dura - outside
Arachnoid - middle
then the CSF
Pia - layer around the spinal cord

100
Q

What layer of the meninges is stretched/can be seen in spina bifida?

A

Dura mater

101
Q

What matter is interior in the spinal cord and exterior in the brain?

A

Gray matter

102
Q

Name the 3 horns of gray matter in the spinal cord?

A

Dorsal, ventral, lateral

103
Q

The Dorsal Root is completely

A

Afferent/Sensory

104
Q

The Ventral Root is completely

A

Efferent/Motor

105
Q

Where do autonomic motor neurons arise from?

A

Lateral horn

106
Q

How many pairs of Spinal nerves are there and what is the regional breakdown?

A
31 pairs
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
107
Q

What is the basal lamina and loose CT around Schwann cells called?

A

Endoneurium

108
Q

What surrounds spinal nerve “fascicles”

A

Perineurium

109
Q

What surrounds the entire spinal nerve?

A

Epineurium

110
Q

Where are unipolar neurons found?

A

Dorsal Root ganglion

111
Q

Where are PNS motor nerve cell bodies found?

A

Ventral or lateral horns of the spinal cord.

112
Q

Where are the only places where there is one way traffic?

A

Roots

113
Q

What 2 main branches do each spinal nerve have?

A

Dorsal ramus

Ventral ramus

114
Q

What are the 3 classifications of nerve fibers and which one is unmyelinated?

A

A, B, and

C (unmyelinated)

115
Q

What are the 4 divisions of A fibers and what do they do?

A

A- alpha (skeletal, proprioception)
A - beta (skin sensory)
A - gamma (motor efferent)
A - delta (sensory, dentin/pulp, fast pain, temp)

116
Q

What fibers are autonomic preganglionic sympathetic?

A

B fibers

117
Q

What fibers elicit dull slow pain?

A

C fibers

118
Q

What general pattern does anesthetic follow in blocking of nerve fibers?

A

Thin ones blocked first

so A-alpha is the last one blocked

119
Q

Why would a patient still feel pressure?

A

That sense is in the large A-alpha type fibers.

120
Q

What is the sensation of pain called?

A

Nociception

121
Q

What substances stimulate nociception upon injury?

A

serotonin, protaglandins, histamine, K+, and ATP, and bradykinin

122
Q

Are there any nociceptors in the brain?

A

No

123
Q

From whence comes visceral pain?

A

organs

124
Q

What defines an analgesic?

A

Maintain consciousness

125
Q

What is a general term for dysfunction in the PNS?

A

Neuropathy

126
Q

How do local anasthetics work?

A

They inhibit the influx of Na+ ions across a membrane

127
Q

What are the 3 components to a local anesthetic?

A

aromatic ring
ester or amide
amine

128
Q

Ester based anesthetic example:

A

cocaine, chloroprocaine

129
Q

Amide based anesthetic example:

A

lidocaine

130
Q

Describe the general mechanism for a local anesthetic.

A

Base forms a salt to pass through epineurium and recombines in the cytoplasm to block Na+ channels

131
Q

What is the fewest number of synapses a reflex can have?

A

one

132
Q

Example of a monosynaptic reflex:

A

stretch receptor

133
Q

Example of polysynaptic reflex:

A

withdraw reflex

134
Q

When you almost fall asleep and jerk your head, what type of reflex is that?

A

monosynaptic

135
Q

What type of receptor initiates the stretch reflex?

A

Muscle spindles inervated with type a-alpha sensory neurons

136
Q

What type of inhibition is part of the stretch reflex?

A

reciprocal (so one signal comes in - two go out)

137
Q

What intermediate step is present in the patellar reflex arc?

A

Interneuron initiates inhibitory response (relaxing opposing muscle)

138
Q

What prevents muscles from contracting excessively?

A

The Golgi tendon reflex

139
Q

What additional feature is there to a crossed extensor reflex?

A

Interneuron needs to cross spinal cord to initiate additional contraction contralateral to balance

140
Q

What two muscle fibers (type/location) are in the flexor withdrawal/crossed extensor reflex?

A

Type A-delta ipsilateral

Type A-delta contralateral

141
Q

The autonomic nervous system is entirely…

A

Motor

142
Q

Where is the cell body in a presynaptic neuron of the autonomic nervous system?

A

CNS

143
Q

Where is the cell body in a postsnynaptic neuron of the autonomic nervous system?

A

Ganglion

144
Q

Are postganglionic nerve fibers myelinated?

A

no

145
Q

What characteristics to post-ganglionic axons have in the sympathetic division of the ANS?

A

Long, unmyelinated, branched

146
Q

Where do preganglionic neurons of the Sympathetic division of the ANS originate in the spinal cord?

A

T1-L2

147
Q

Where do preganglionic neurons of the Parasympathetic division of the ANS originate in the spinal cord?

A

Either brainstem or S2-S4

148
Q

Parasympathetic preganglionic axons are:

A

Long and myelinated

149
Q

Parasympathetic postganglionic axons are:

A

Short and unmyelinated

150
Q

What are the four cranial nerves involved in parasympathetic division?

A

III, VII, IX, and X

151
Q

The somas of preganglionic sympathetic neurons are in the:

A

Lateral Horn of the gray matter in T1-L2

152
Q

How to remember Sympathetic pre and post ganglionic fiber lengths?

A

Think chain ganglia. Right next to spinal cord so unmyelinated post fiber is long

153
Q

What are ganglia outside the Chain ganglia for Sympathetic division?

A

Collateral (aka prevertebral)

154
Q

What two Rami connect the spinal nerve to the sympathetic chain ganglia?

A

White and Gray Rami

155
Q

Where do Splanchnic nerves go?

A

Carry preganglionic sympathetic fibers to collateral (prevertebral) ganglia.

156
Q

What fiber type are postgangionic?

A

C fibers (unmyelinated)

157
Q

Where are 3 places sympathetic collateral ganglia innervate?

A

celiac, superior/inferior mesenteric)

158
Q

Adrenal Medulla cells can be considered…

A

postganglionic sympathetic neurons

159
Q

What class of molecule is epinepherine/norepinepherine?

A

catecholamines

160
Q

T/F

The ganglionic fiber innervating the adrenal medulla has no synapse prior.

A

True

161
Q

Where are parasympathetic ganglia generally located?

A

Close to or within the target organ.

162
Q

What nervous system controls the digestive tract?

A

Enteric.

163
Q

What neurotransmitter does the parasympathetic nervous system use?

A

ACh - the entire system is cholinergic - both pre and post ganglionic neurons

164
Q

What neurotransmitters does the sympathetic nervous system use?

A

Both cholinergic and andrenergic

165
Q

What do most post sympathetic neurons release as neurotransmitter?

A

norepinepherine (andrenergic)

166
Q

What sympathetic postganglionic neurons are cholinergic?

A

Sweat glands, blood vessels,

167
Q

The sympathetic adrenal innervation releases what transmitter at the medullary synapse?

A

ACh

168
Q

What two cholinergic receptors are there in the ANS?

A

Nicotinc - always stimulatory

Muscarinic - stimulatory/inhibitory

169
Q

What two andrenergic receptors are there in the ANS?

A

Alpha - mostly stimulatory

Beta - excitatory / inhibitory (depends on subtype)

170
Q

Beta-1 adrenergic receptor does what to the heart?

A

Stimulates

hence beta blockers

171
Q

Beta-2 andrenergic receptor does what?

A

Relaxes bronchial smooth muscle

172
Q

What are some examples of singular (sympathetic) innervation?

A

Erector pili, adrenal medulla, some sweat glands

173
Q

What is sympathetic tone?

A

firing frequency results in single-innervated sympathetic system.

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