Exam 4, Chapter 12: The Spinal Cord Flashcards

1
Q

dorsal root ganglia are?

A

Sensory neurons

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2
Q

Surrounding the Neural tube,

Interneurons (assosiciation neurons), which receive sensory input from sensory neurons come from?

A

dorsal cells

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3
Q

Surrounding the Neural tube,

Motor neurons from?

A

ventral cells!

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4
Q

enclosed within the vertebral column from the foramen magnum to L1 / L2

A

Spinal Cord Gross Anatomy

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5
Q

afferent fibers (sensory)

A

Spinal Cord Gross Anatomy

Ascending fibers

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6
Q

efferent fibers (motor)

A

Spinal Cord Gross Anatomy

Descending fibers

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7
Q

protected by bone, meninges, and CSF

A

Spinal Cord Gross Anatomy

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8
Q

space between the vertebrae and the dural sheath (dura mater) which isfilled with fat and a network of veins

A

Spinal Cord Gross Anatomy

Epidural Space

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9
Q

Epidural anesthesia is delivered into this space via flexible cannula

A

Spinal Cord Gross Anatomy

Epidural space

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10
Q

terminal portion of the spinal cord

A

Spinal Cord Gross Anatomy

Conus medullaris

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11
Q

End of cord narrows to a cone shape between L1 and L2

A

Spinal Cord Gross Anatomy

Conus Medullaris

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12
Q

fibrous extension of the pia mater; anchors the spinal cord to the coccyx

A

Spinal Cord Gross Anatomy

Filum terminale

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13
Q

delicate shelves of pia mater; attach the spinal cord to the vertebrae

A

Spinal Cord Gross Anatomy

Denticulate ligaments

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14
Q

31 pairs attach to the cord by paired roots

A

Spinal Cord Gross Anatomy

Spinal nerves

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15
Q
8 cervical pair; 
12 thoracic pair; 
5 lumbar pair; 
5 sacral pair; 
1 coccygeal
A

Spinal Cord Gross Anatomy

Spinal Nerves

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16
Q

sites where nerves serving the upper and lower limbs emerge, so large ventral horns and multiple nerve roots leaving the cord in these regions

A

Spinal Cord Gross Anatomy

Cervical and Lumbar Enlargements

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17
Q

collection of nerve roots at the inferior end (below L2)

A
Spinal Cord Gross Anatomy
Cauda equina (horse tail)
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18
Q
  • Dura mater (single layer only; no periosteal attachment)
  • Arachnoid mater with CSF in subarachnoid space
  • Pia mater
A

Spinal Cord Gross Anatomy

Meninges

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19
Q

also circulates in the central canal which continues superiorly into the medulla oblongata

A

Spinal Cord Gross Anatomy

CSF

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20
Q

separates ventral funiculi (white matter tract regions)

A

Cross-Sectional Anatomy of Spinal Cord

Ventral median fissure

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21
Q

divides dorsal funiculi (white matter tract regions)

A

Cross-Sectional Anatomy of Spinal Cord

Dorsal median sulcus

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22
Q

consists of soma, unmyelinated processes and neuroglia

A

Cross-Sectional Anatomy of Spinal Cord
Gray Matter Columns
Gray Matter

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23
Q

connects R / L masses of gray matter; encloses central canal

A

Cross-Sectional Anatomy of Spinal Cord
Gray Matter Columns
Gray Commissure

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24
Q

Interneurons (Therefore, a sensory synapse will occur here)

A

Cross-Sectional Anatomy of Spinal Cord
Gray Matter Columns
Dorsal Horns

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25
Q

Somatic (voluntary) motor neurons & some interneurons

A

Cross-Sectional Anatomy of Spinal Cord
Gray Matter Columns
Ventral Horns

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26
Q

Contain sympathetic motor fibers; this column is present in T1-L2 only

A

Cross-Sectional Anatomy of Spinal Cord
Gray Matter Columns
Lateral Horns

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27
Q

dorsal root ganglion (sensory nerve cell bodies) lead to dorsal roots which
expand into rootlets before entering the spinal cord

A

Cross-Sectional Anatomy of Spinal Cord
Spinal Roots
Dorsal half

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28
Q

May synapse at a dorsal horn interneuron or continue via axons in the white matter
columns towards the brain

A

Cross-Sectional Anatomy of Spinal Cord
Spinal Roots
Dorsal Half

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29
Q

motor rootlets join to form motor roots

A

Cross-Sectional Anatomy of Spinal Cord
Spinal Roots
Ventral half

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30
Q

fuse laterally to form short spinal nerves

A

Cross-Sectional Anatomy of Spinal Cord
Spinal Roots
Dorsal and ventral roots

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31
Q

Body representation in four zones (maintain spatial relationships)

A

Cross-Sectional Anatomy of Spinal Cord
Spinal Roots
Gray matter Somatotopy

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32
Q

visceral sensory (VS), visceral motor (VM)

A

Cross-Sectional Anatomy of Spinal Cord
Visceral representation on the internal aspect
Gray matter Somatotopy

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33
Q

Somatic representation on the external aspect

A

Cross-Sectional Anatomy of Spinal Cord
Gray matter Somatotopy
somatic sensory (SS), somatic motor (SM)

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34
Q

ascending, descending, and transversely

A

Cross-Sectional Anatomy of Spinal Cord
White Matter Columns
Three Directions of Fiber movement

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35
Q

dorsal, ventral, lateral (T1-L2 only)

A

Cross-Sectional Anatomy of Spinal Cord
White Matter Columns
are Divided into three columns (funiculi)

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36
Q

Each white matter column contains several fiber tracts

  • Fiber tract names reveal their origin and destination
  • Fiber tracts are composed of bundled axons with similar sensory functions
A

Cross-Sectional Anatomy of Spinal Cord

White Matter Columns

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37
Q

All pathways decussate at some point

  • Most consist of two or three neurons (relays)
  • Most maintain somatotopy (organizational mapping)
  • Pathways are paired (one on each side of the spinal cord or brain)
A

Neuron Pathways: Sensory (Afferent-Ascending)

General Features

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38
Q

(of two or more things) cross or intersect each other to form an X.

A

Neuron Pathways: Sensory (Afferent-Ascending)

decussate

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39
Q

The central processes of “first-order neurons” branch diffusely as they enter the spinal cord
and medulla
-conduct impulsees and proprioceptors
-most synapse with 2nd-order neurons (interneuron) in the spinal cord or medullary nuclei

A

Neuron Pathways: Sensory (Afferent-Ascending)

Ascending Pathway Organization

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40
Q

conduct impulses from cutaneous receptors (discriminative touch, pressure, vibration , temperature, pain)

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Conduct impulses
First Order Neuron

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41
Q

(feedback on position of joints & relative movement of joints)
-other branches take part in “spinal cord reflexes”

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Proprioceptors

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42
Q

most branches synapse with these, aka “interneuron” in the spinal cord or medullary nuclei
(nuclei in medulla oblongata)

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Second-order neurons

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43
Q

“red nucleus”

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Medulla oblongata nuclei

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44
Q

Location of third order-(inter)neuron

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Axons extend to thalamus

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45
Q

Extension of Third Order Neuron Axons

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Primary Somatosensory Cortex

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46
Q

Subconscious Second Order Axons where?

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Cerebellum
no additional synapses

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47
Q

Three Ascending Pathways?
Which send impulses to contralateral somatosensory cortex via thalamus?
Which sends ipsilateral impulses to cerebellum and do not contribute to sensory perception?

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
1. Dorsal Column- Medial Lemniscal Pathway
2. Spinothalamic Pathway
3. Spinocerebellar Pathway

a. 1 and 2
b. 3

48
Q

Three Ascending Pathways
-These pathways are responsible for discriminative touch and pressure, vibration
and conscious proprioception
-Many receptors in a small area (dense receptive field), so easy to localize the
source of sensation precisely

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Dorsal Column-Medial Lemniscal Pathway (Dorsal Tract Location)

49
Q

Three Ascending Pathways
-First-order fibers travel into & ascend the spinal cord along the dorsal white
columns, synapsing at the corresponding nuclei in the medulla oblongata.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Dorsal Column-Medial Lemniscal Pathway (Dorsal Tract Location)

50
Q

Three Ascending Pathways

-The second-order fibers decussate in the medulla and synapse in the thalamus.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Dorsal Column-Medial Lemniscal Pathway (Dorsal Tract Location)

51
Q

Three Ascending Pathways

-Third-order fibers terminate in the somatosensory cortex.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Dorsal Column-Medial Lemniscal Pathway (Dorsal Tract Location)

52
Q

Three Ascending Pathways

-These pathways are responsible for temperature, pain, coarse touch and pressure

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinothalamic Pathway
(Ventral and Lateral tract locations)

53
Q

Three Ascending Pathways

-Fewer receptors, so aware of the sensation, but not as precisely localized

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinothalamic Pathway
(Ventral and Lateral tract locations)

54
Q

Three Ascending Pathways

-First-order fibers synapse in the dorsal horn of the spinal cord.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinothalamic Pathway
(Ventral and Lateral tract locations)

55
Q

Three Ascending Pathways
-Second-order fibers decussate at the same spinal cord level, ascend the
spinothalamic fiber tracts and synapse in the thalamus.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinothalamic Pathway
(Ventral and Lateral tract locations)

56
Q

Three Ascending Pathways

-Third-order fibers terminate in the somatosensory cortex.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinothalamic Pathway
(Ventral and Lateral tract locations)

57
Q

Third Ascending Pathway

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinocerebellar Pathway

58
Q

Three Ascending Pathways

-These pathways are responsible for subconscious proprioception.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinocerebellar Pathway

59
Q

Three Ascending Pathways

-The tracts terminate in the cerebellum and therefore do not contribute to sensory perception.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinocerebellar Pathway

60
Q

Three Ascending Pathways

-First-order neurons synapse in the dorsal horn of the spinal cord.

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinocerebellar Pathway

61
Q

Three Ascending Pathways

-Second-order fibers terminate in the “ipsilateral cerebellum.”

A

Neuron Pathways: Sensory (Afferent-Ascending)
Ascending Pathway Organization
Spinocerebellar Pathway

62
Q

Descending Pathways
-Descending tracts deliver impulses from the brain to the spinal cord, and are divided into
two groups

A

Neuronal Pathways: Motor (Efferent/Descending)

General Feature

63
Q

Descending Pathways
-(from the motor cortex) , decussate at MEDULLA. descend from the motor
cortex regions and do not synapse until reaching the correct spinal cord level

A

Neuronal Pathways: Motor (Efferent/Descending)
General Features
=Direct pathways = pyramidal tracts

64
Q

Descending Pathways
-(all others from the cerebellum, basal
ganglia, etc.) descend from sub-cortical motor nuclei and are multi-synaptic, complex
and often influenced via reflex activity

A

Neuronal Pathways: Motor (Efferent/Descending)
General Features
=Indirect Pathway=extrapyramidal tracts

65
Q

Descending Pathways

-Motor pathways involve two motor neurons (upper and lower)

A

Neuronal Pathways: Motor (Efferent/Descending)

General Features

66
Q

Descending Pathways

-pyramidal cells of the motor cortex and the neurons of the subcortical motor nuclei

A

Neuronal Pathways: Motor (Efferent/Descending)

Upper Motor Neuron (UMN)

67
Q

Descending Pathways

-ventral horn motor neurons which directly innervate the skeletal muscles

A

Neuronal Pathways: Motor (Efferent/Descending)

Lower Motor Neuron (LMN)

68
Q

Descending Pathways

-The direct pathway regulates fast and fine (skilled) movements

A

Neuronal Pathways: Motor (Efferent/Descending)

Direct (Pyramidal System)

69
Q

Descending Pathways

  • UMN - Most fibers originate in the pyramidal neurons in the primary motor cortex and related motor cortices
  • Lateral tracts decussate at medulla pyramids
  • Ventral tracts decussat at spinal cord level
A

Neuronal Pathways: Motor (Efferent/Descending)
Direct (Pyramidal System)
Pathway Specific

70
Q

Descending Pathways

  • Impulses descend the corticospinal tracts (lateral and ventral)
  • lateral decussate at medulla pyramid
  • ventral tracts decussate at spinal cord level
A

Neuronal Pathways: Motor (Efferent/Descending)
Direct (Pyramidal System)
Pathway Specific

71
Q

Descending Pathways
-impulses synapse in the
ventral horn (with an interneuron or directly to a LMN); innervate skeletal muscles

A

Neuronal Pathways: Motor (Efferent/Descending)
Direct (Pyramidal System)
Pathway Specific

72
Q

Descending Pathways

-Lateral tracts (>80%) decussate at the medullary pyramids

A

Neuronal Pathways: Motor (Efferent/Descending)
Direct (Pyramidal System)
Pathway Specific

73
Q

Descending Pathways

-parts innervate cranial nerve nuclei

A

Neuronal Pathways: Motor (Efferent/Descending)
Direct (Pyramidal System)
Pathway Specific

74
Q

Descending Pathways

These motor pathways modulate pyramidal input, primarily affecting

  • Axial muscles that maintain balance and posture (=postural tone)
  • Muscles controlling coarse movements of the proximal limb joints
  • Control of complex, multi-joint movements
  • Head, neck and eye movement coordination
A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
General Features

75
Q

Descending Pathways
-UMN Fibers originate in the basal ganglia, substantia nigra, cerebellum, various brain stem
vestibular nuclei & some in the sensory cortex

A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
Pathway Specific

76
Q
Descending Pathways
Tracts primarily descend through the reticular formation (pons & medulla) UMN to LMN through
Include:
-Reticulospinal tract
-Vestibulospinal
-Rubrospinal
-Tectospinal tracts
A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
Pathway Specific

77
Q

Descending Pathways

  • Reticular formation origin
  • maintain balance via Posture
A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
Pathway Specific
Reticulospinal Tracts

78
Q

Descending Pathways

  • Vestibular nuclei origin
  • maintain balance via posture
A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
Pathway Specific
Vestibulospinal tracts

79
Q

Descending Pathways

  • Red nucleus origin
  • control of Flexor Muscles
A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
Pathway Specific
Rubrospinal tracts

80
Q

Descending Pathways

  • Superior colliculi origin
  • mediates head & neck following eye movements
A

Neuronal Pathways: Motor (Efferent/Descending)
Indirect (Extrapyramidal) System
Pathway Specific
Tectospinal tracts

81
Q

Clinical Correlates

Loss of motor function

A

Paralysis

82
Q

-severe damage to the ventral root or ventral horn cells

A

Flaccid Paralysis

83
Q

-Lower motor neurons are damaged and impulses do not reach muscles

A

Flaccid Paralysis

84
Q

-There is no voluntary or involuntary control of muscles

A

Flaccid Paralysis

85
Q

-only upper motor neurons are damaged

A

Spastic Paralysis

86
Q

-Spinal neurons remain intact and muscles are stimulated irregularly by reflex activity

A

Spastic Paralysis

87
Q

-There is no voluntary control of muscles

A

Spastic Paralysis

88
Q

-contralateral side of body affected

opposite side affected

A

Spastic Paralysis

hemiplegia

89
Q

Clinical Correlate
-A complete transection of the spinal cord at any level results in total motor and sensory loss
in regions inferior to the cut

A

Spinal Cord Injury (SCI) and Transection

90
Q

Clinical Correlate

-transection between T1 and L1 (affects trunk & lower extremities)

A

Spinal Cord Injury (SCI) and Transection

Paraplegia

91
Q

Clinical Correlate

-transection in the cervical region (affects trunk & all extremities)

A

Spinal Cord Injury (SCI) and Transection

Quadriplegia

92
Q

Clinical Correlate

-Damage to the ___ causes sensory loss inferior to the level of damage

A

Spinal Cord Injury (SCI) and Transection

dorsal columns

93
Q

Clinical Correlate
-Damage to the ____ would cause a combination of motor & sensory
loss inferior to the level of damage

A

Spinal Cord Injury (SCI) and Transection

ventral or lateral columns

94
Q

Clinical Correlates
classifications : ASIA A, B, C, D, E
A Worst
E Normal function

A

Spinal Cord Injury (SCI) and Transection

American spinal Injury Assocation classifications

95
Q

Clinical Correlates

Destruction of the ___ by the poliovirus

A

Poliomyelitis

Ventral horn motor neurons

96
Q
Clinical Correlates
Early symptoms:
-fever, 
-headache, 
-muscle pain and weakness, 
-loss of somatic reflexes
A

Poliomyelitis

97
Q

Clinical Correlates
Advanced symptoms –
-paralysis & muscle atrophy;
-recent surge in post-polio syndrome

A

Poliomyelitis

98
Q

Clinical Correlates

Vaccines are readily available and can prevent infection

A

Poliomyelitis

99
Q

Clinical Correlates

  • a.k.a. Lou Gehrig’s disease;
  • modern face of ALS = Stephen Hawking
A

Amyotrophic Lateral Sclerosis (ALS)

100
Q

Clinical Correlates

-Progressive destruction of ventral horn motor neurons and fibers of the pyramidal tract

A

Amyotrophic Lateral Sclerosis (ALS)

101
Q

Clinical Correlates

-Symptoms – progressive loss of the ability to speak, swallow and breathe

A

Amyotrophic Lateral Sclerosis (ALS)

102
Q

Clinical Correlates

-Linked to malfunctioning genes for glutamate transporter (= excess excitotoxic glutamate)

A

Amyotrophic Lateral Sclerosis (ALS)

103
Q

Clinical Correlates

  • Death typically occurs within five years;
  • Drug which inhibits glutamate signaling promising
A

Amyotrophic Lateral Sclerosis (ALS)

104
Q

Clincal Correlate

  • Incomplete closure of neural tube (caudal vertebral arches);
  • no laminae or spinous process
A

Spina Bifida

105
Q

Clincal Correlate

Varying degrees of severity

A

Spina Bifida

106
Q

Clincal Correlate

-Mild form: ; hair patch / birth mark /dimple only

A

Spina Bifida

-Spina bifida occulta (20% of population)

107
Q

Clincal Correlate

-Most severe form: (out-pocketing of meninges, CSF & spinal cord)

A

Spina Bifida

Myelomeningocele

108
Q

Clincal Correlate

Prenatal ___ essential for complete neural tube closure

A

Spina Bifida

folic acid

109
Q

CNS is established during the ___ month of development

A

first

110
Q

Gender-specific areas appear in response to ___ (or lack thereof, if a Y chromosome)

A

testosterone

111
Q

Maternal exposure to
-Radiation, drugs (e.g., alcohol and opiates), or infection can harm the fetus’ developing CNS
-Smoking decreases oxygen in the blood, which leads to neuron death & fetal brain damage
-

A

duh

112
Q

The ___ s is one of the last areas of the CNS to develop

A

hypothalamu

113
Q

___ develops slowly over the first 11 weeks

A

Visual cortex

114
Q

Growth and maturation of the nervous system occurs throughout childhood and reflects
___

A

progressive myelination

115
Q

Normal aging brings some cognitive declines, but these are not significant in healthy individuals until they reach their 80s

A

fact

116
Q

Excessive use of alcohol causes signs of senility unrelated to the aging process

A

truth