1.4- Anatomy of Cerebellum, Brain Stem, & SC Flashcards
0
Q
What controls balance, posture maintenance, and complex muscular movements?
A
Cerebellum
1
Q
What is responsible for integration, coordination, and execution of multijoint movements?
A
Cerebellum
2
Q
What is located between cerebrum and SC?
A
Brain stem
3
Q
What is the function of the brainstem?
A
To relay
4
Q
Where is the brain stem located?
A
Between cerebrum and SC
5
Q
What is the midbrain?
A
A relay station between cerebrum and SC
6
Q
What is important in reflex including righting of the head and auditory reflexes?
A
Midbrain
7
Q
What is made of fibers running between cerebellum and rest of CNS?
A
Pons
8
Q
What is important for balance, equilibrium, coordinating movement?
A
Pons
9
Q
Why is the Pons important?
A
for balance, equilibrium, coordinating movement
10
Q
Why is the Medulla Oblongata important?
A
It is the control center for heart and breathing rate.
11
Q
Where does the decussation (crossing) of motor and sensory neurons occur?
A
Medulla Oblongata
12
Q
What contains the Reticular Activating System?
A
Medulla Oblongata
14
Q
What is the Reticular Activating System?
A
adjusts level of arousal and sleep-wake cycles
15
Q
What is the Foramen Magnum?
A
large opening at the base of the skull that serves as a boundary between brainstem and SC
16
Q
What is the Spinal Column?
A
bony structure that protects SC
17
Q
How far down does the spinal cord extend?
A
the first lumbar vertebrae
18
Q
Nerve roots from the SC at the thoracic and lumbar level must descend _____ before exiting.
A
2 levels
19
Q
How many enlargements in the spinal cord?
A
2- first enlargement (cervical enlargement) and second enlargement (lumbar enlargement)
20
Q
Where is the first enlargement located?
A
third cervical vertebrae through second thoracic segment
21
Q
Why is the first enlargement wider?
A
because of the many sensory and motor neurons coming from the UE’s
22
Q
Where is the narrow area of the spinal cord?
A
thoracic area
23
Q
Why is the thoracic area of the spinal cord narrow?
A
because relatively few motor and sensory neurons from this area
24
Q
Where is the second enlargement of the spinal cord located?
A
first lumbar through third sacral
25
Why is the lumbar area of the spinal cord enlarged?
because of number of sensory and motor connections from LE's
26
Generally the SC is _____ at top than bottom because nerves join the SC as it ______
larger at top
ascends
27
At approx. L1 the SC becomes a cone shaped structure called the _____________
Conus Medullaris
28
Where does the SC become the Conus Medullaris?
L1
29
What makes the Conus Medullaris?
sacral spinal segments
30
Below the Conus Medullaris the SC ends in a mass of spinal nerve roots called the _____________
Cauda Equina
31
What is the Cauda Equina?
a mass of spinal nerve roots after the Conus Medullaris
32
In the brain, the Dura has 2 layers. It the SC, the dura has 1 layer. The layer is ____________.
Visceral layer (no periosteal layer in the SC)
33
Dura does not adhere to bone- it forms a ____.
sac
34
Why does the Dura not adhere to bone and instead form a sac?
because the spinal column is flexible and it would tear with movement if attached
35
True or False: The Arachnoid is the same in the SC as it is in the brain.
True. I is pushed against Dura due to SCF pressure but not physically attached.
36
The Pia is connected to ____________.
the SC itself
37
What term describes the flaps in the pia that attach through the arachnoid to the Dura, anchors the SC?
Denticulate ligaments
38
What are Denticulate Ligaments?
flaps in the pia that attach through the arachnoid to the dura, anchors the SC
39
Pia continues around the cauda equine down to the coccyx where it forms a strand and attaches to anchor the SC- called the ____________
Filum Terminale
40
Where does the dural sac eventually join the filum terminale and attach to the coccyx?
External Filum Terminale or the Coccygeal Ligament
41
In the SC, white matter is ______ while the gray matter is __________.
white matter is outside while the gray matter is inside
42
In the SC, gray matter is divided into __________.
3 horns: dorsal (posterior) horn, lateral horn, and ventral (anterior) horn
43
Dorsal horn is ___________.
Lateral horn is ___________.
Ventral horn is _________.
Dorsal horn- sensory
Lateral horn- motor
Ventral horn- motor
44
Cell bodies of neurons that carry sensory info up to the brain.
Dorsal (posterior) horn
45
Contains cell bodies of preganglionic sympathetic neurons
Lateral horn
46
Processes autonomic info
Lateral horn
47
Found only between T1-L2
Lateral horn
48
Lateral horn contains cell bodies of ____________ neurons.
preganglionic sympathetic
49
Lateral horn processes ___________ and is found only between __________.
processes autonomic info
found only between T1-L2
50
Ventral horn is cell bodies of _______ neurons that drive ________.
Alpha motor neurons
drive voluntary muscle
51
Cell bodies of Alpha motor neurons that drive voluntary muscle
Ventral (anterior) horn
52
White matter is divided into ____________.
3 columns: Dorsal (posterior) column, lateral column, ventral (anterior) column
53
Dorsal column is ________.
Lateral column is _________.
Ventral column is __________.
Dorsal column is sensory fibers running up to the brain.
Lateral column is both motor and sensory fibers.
Ventral column is mostly motor fibers.
54
Ventral columns are made of several distinct bundles called _______.
tracts
55
a tract is a group of nerve fibers similar in ______, ___________, and ____________.
origin, destination, and function
56
- large with slightly flattened shape
| - more white matter with large ventral horn
cervical
57
- ventral horn is narrow (few muscles in the area)
| - small dorsal horn- little sensation coming from the area
thoracic
58
- broadens with large dorsal and ventral horns due to lots of motor and sensory activity from the area
lumbar
59
- lots of gray matter with very little white matter (tracts mostly entre or leave the SC at levels about this region)
sacral
60
SC has ____ segments with a pair of ________ coming from each segment
31
spinal nerves
61
All segments have _______ and _______ components except C1 which only has _______.
sensory and motor
motor
62
What part of the SC does not have both motor and sensory components.
C1- sensory info carried thru cranial nerves
63
Each spinal nerve is made of what 2 roots?
dorsal root and ventral root
64
The dorsal root is made of _________ fibers.
afferent (sensory)
65
The ventral root is made of __________ fibers.
efferent (motor)
66
Enlargement of the dorsal root that contains the cell bodies of sensory neurons (cell bodies are outside the SC itself)
Dorsal Root Ganglion
67
What is the Dorsal Root Ganglion?
enlargement of the dorsal root that contains the cell bodies of sensory neurons
68
Union of the dorsal and ventral roots forms the _________.
spinal nerves
69
Tracts (white matter)- columns consist of several tracts- bundles of ____________ that run up and down the cord.
myelinated fibers
70
Lateral Corticospinal Tract does what?
voluntary motor system
71
Starts in area 4 of the cortex (Brodmann's cortical numbering system) and eventually innervates muscle
Lateral Corticospinal Tract
72
Corresponds with the Homunculus in the primary motor cortex
Lateral Corticospinal Tract
73
The Lateral Corticospinal Tract corresponds with the ___________ in the primary motor cortex.
Homunculus
74
Motor tracts are a 2 neuron system- _______ and _______ _______ neuron
upper and lower motor neuron
75
The Upper Motor Neuron begins in the ________, runs through the ________ to the _________.
Begins in the cortex, runs through the internal capsule to the medulla oblongata
76
In the medulla, 85% of the fibers cross and descend through the SC as the ___________.
Lateral Corticospinal Tract
77
The 15% that don't immediately cross ___________.
do so eventually
78
The axon exits the SC through the _______ where it synapses onto an ______ or directly onto the ___________.
through the Ventral horn where it synapses onto an interneuron or directly onto the Lower Motor Neuron
79
The lower motor neuron is generally an __________.
Alpha Motor Neuron
80
The lower motor neuron then travels through the _________ to ___________.
Ventral root to innervate muscles
81
If the upper motor neuron is destroyed:
1.
2.
3.
1. effects seen on opposite side
2. paralysis, hypertonic, hyperreflexia- Spastic Paralysis
3. Minimal atrophy
82
```
If lower motor neuron is destroyed:
1.
2.
3.
4.
```
1. effects on the same side
2. paralysis, flaccid, atonia, no reflexes- Flaccid paralysis
3. significant atrophy
4. may see fasciculations of the muscle fibers
83
If both upper and lower motor neurons destroyed:
| 1.
1. characteristics of lower motor neuron lesion- no reflexes, flaccid paralysis
84
Destroyed upper or lower motor neuron:
1. effects on the same side?
2. minimal atrophy?
3. Flaccid paralysis?
4. fasciculations of the muscle fibers?
1. lower motor neuron
2. upper motor neuron
3. lower motor neuron
4. lower motor neuron
85
Dorsal Column System can't be called a tract because it ______________.
originates outside the CNS
86
What carries vibration and light touch?
Dorsal Column System
87
What has large myelinated fibers (fast)?
Dorsal Column System
88
What carries pain, temp, some touch?
Lateral Spinothalamic Tract
89
What has very small unmyelinated fibers- slow conduction?
Lateral Spinothalamic tract
90
What are the differences between the dorsal column system and the lateral spinothalamic tract?
1. myelination
2. where it synapses
3. where it crosses
91
```
Dorsal Column System~
#1 neuron enters thru the _____ into the SC on the _____; travels up the SC on the _____ into the _____ where it synapses with neuron #2; #2 neuron crosses to the _______ as it goes through the _____ & into the ______; #2 neuron synapses with the #3 neuron in the _____ and goes to area ____________
```
```
dorsal root
same side
same side
medulla oblongata
opposite side
brainstem & into the thalamus
thalamus and goes to area 3, 2, 1, of sensory cortex
```
92
Where does the dorsal column system cross to the opposite side?
as it goes through the brainstem and into the thalamus
93
```
Lateral Spinothalamic tract~
#1 neuron enters through the _____ into the ____ and synapses immediately; #2 neuron crosses in the _____ of the SC to the ______ before it ascends up the SC; #2 neuron end and synapses with #3 neuron in the ______; #3 neuron runs up to ______________
```
dorsal root into the dorsal horn
lateral column of the SC to the opposite side
thalamus
3, 1, 2, in sensory cortex
94
Where does the lateral spinothalamic tract cross to the opposite side?
crosses in the lateral column of the SC to the opposite side before it ascends up the SC
