Introduction to the Nervous System Flashcards
1
Q
What is Gray matter?
A
A collection of neuron cell bodies
2
Q
What is a nucleus of the gray matter?
A
A cluster of neuron cell bodies that are morphologically distinct from other neurons
3
Q
What is a lamina of the gray matter?
A
layer or band of spinal cord made of gray matter
4
Q
What are bodies of gray matter?
A
Usually nuclei (ex: geniculate bodies/nuclei of thalamus)
5
Q
What is the cortex of gray matter?
A
Fray matter located on a surface (cerebral and cerebellar cortex)
6
Q
What is white matter?
A
An aggregation of neuronal processes/axons
7
Q
What is a tract of white matter?
A
A collection of neuronal fibers/ axons that are anatomicall yor functionally distinct
8
Q
What is a fasciculus of white matter?
A
Bundle of axons/fibers, same as tract
9
Q
What is a lemniscus of white matter?
A
Ribbon or band of axons/fibers, same as tract
10
Q
What is a funiculus of white matter?
A
Cord or column of white matter in spinal cord that includes several fasciculi/tracts
11
Q
What is the ascending fibers/axons of white matter?
A
Rostrally (up towards the nose), upstream or cranially
12
Q
What is the descending fibers/axons white matter?
A
Caudally or downstream
13
Q
Are there any nerves in the CNS?
A
No, nerves are found external to the CNS
14
Q
What are the divisions of the central nervous system?
A
Spinal Cord
Brainstem
Cerebellum
Cerebrum
15
Q
What is the brainstem?
A
The part of the brain that connects the spinal cord to the cerebrum and cerebellum
16
Q
What is the brainstem also referred to as?
A
Bulb or bulbar
17
Q
Does the brainstem contain gray matter?
A
Yes it includes gray matter areas or nuclei
18
Q
Does the brainstem contain white matter?
A
Yes, white matter includes ascending and descending tracts of fibers
19
Q
What are the three divisions of the brainstem?
A
Medulla
Pons
Midbrain
20
Q
What are the gray matter areas of the medulla?
A
Inferior Olivary Nuclei
Cranial nerve nuclei
21
Q
What are the inferior olivary nuclei?
A
Large nuclei
Paired nuclear complex (right and left)
Forms landmarks on the ventrolateral surface called olives
22
Q
What are the cranial nerve nuclei of the medulla?
A
clusters of neurons that contribute fibers to or receive fibers from a cranial nerve
23
Q
What cranial nerves are part of the cranial nerve nuclei of the medulla?
A
XII XI X IX VIII (part of complex) V (part of complex)
24
Q
What are the white matter areas of the medulla?
A
Both ascending and descending fiber tracts
Medullary pyramids
25
What are medullary pyramids?
Paired (right and left)
Landmark structures on ventral surface
Comprised of descending fibers/axons
26
What are corticospinal fibers/axons?
Axons from cerebral cortex to spinal cord
| Provide motor control
27
What are inferior cerebellar peduncles?
Restiform bodies
| Paired structures that help attach the cerebellum to the medulla
28
What is a peduncle?
Stalk or stem
29
What is the function of inferior cerebellar peduncles?
Consists mostly of axons going to and from the cerebellum to and from the medulla
30
What are the two parts of the pons?
Dorsal pons = posterior part
| Ventral pons = Basilar Pons (anterior part)
31
What matter does the dorsal pons consist of?
```
Comprised of many gray and white matter areas including the cranial nerve nuclei of:
VIII (part of)
VII
VI
V (part of)
```
32
What matter make up the ventral pons?
White and Gray Matter
33
What are pontine nuclei ?
Collection of neuron cell bodies in the ventral pons
34
Which part of the pons are pontine nuclei found?
Ventral pons
35
What is the function of the pontine nuclei?
- Receives input from neurons of the ipsilateral cerebral cortex
- Projects axons to the contralateral side of the cerebellum
36
What forms the middle cerebellar peduncle?
Project axons from the pontine nuclei that travel to the contralateral side of the cerebellum and connect the pons to the cerebellum
37
What is the midbrain?
Most superior part of the brainstem
38
What does the midbrain consist of?
Has part of the brain ventricular system
39
What divides the midbrain into 2 portions?
The cerebral aqueduct (of Sylvius)
40
What are the two parts of the midbrain?
Dorsal Midbrain
| Ventral Midbrain
41
What is the dorsal midbrain also known as?
Tectum or roof of the midbrain
42
What is included in the dorsal midbrain?
Includes 2 pair of nuclei, superior and inferior colliculi
43
What is the function of the neurons of the superior colliculi?
Concerned with coordinating certain reflexes in response to visual/auditory data
44
What is the function of the neurons of the inferior colliculi?
Involved in the conscious auditory pathway
45
What is the ventral midbrain formed by?
Formed by a pair of cerebral peduncles that include both white and gray matter
46
What nuclei does the of the ventral midbrain gray matter consist of?
Cranial nerve nuclei
| Substatia nigra
47
Which cranial nerve nuclei are part of the ventral midbrain?
III
IV
Part of V
48
What is the function of the substantia nigra?
motor control
49
What type of matter does the superior cerebellar peduncles consist of?
white matter
50
What does the white matter of the superior cerebellar peduncles do?
fibers connect cerebellum to midbrain and cerebrum
51
what makes up the cerebellar cortex?
most of the gray matter is distributed on the outer surface forming cerebellar cortex
52
how does the cortical surface of the cerebellum appear?
The coritcal surface is highly folded into a series of folia or leaf- like folds
53
What are the deep/subcortical cerebellar nuclei?
some gray matter (nuclei) that are embedded in the medullary center
54
What forms the center or medullary center of the cerebellum?
White matter
55
Which pairs of peduncles connect the cerebellum to the brainstem?
inferior cerebellar peduncles
Middle cerebellar peduncles
superior cerebellar peduncles
56
what part does the inferior cerebellar peduncles connect on the brainstem?
cerebellum to medulla
57
what part does the middle cerebellar peduncles connect on the brainstem?
cerebellum to pons
58
what part does the superior cerebellar peduncles connect on the brainstem?
cerebellum to midbrain
59
What is the function of the cerebellum?
Receives input from most sensory systems and cerebral cortex
- influences the activity of skeletal muscle related to:
1) posture
2) equilibrium
3) coordination/control of movements
60
What two major parts make up the cerebrum?
Diencephalon
| Telencephalon
61
What is the diencephalon?
Forms the core of the cerebrum
| Found in between the cerebral hemispheres
62
what type of matter is the diencephalon made of?
mostly gray matter, with some white matter
63
What separates the two halves of the diencephalon into left and right?
separated by the Third (III) ventricle
64
What parts make up the diencephalon?
Hypothalamus
Thalamus
epithalamus
Subthalamus
65
what is the thalamus?
a collection of neurons/nuclei
66
What is the function of the thalamus?
- relay most sensory information to the cerebral cortex
- involved in motor pathways
- influence other brain activity (behavior, emotions, consciousness)
67
where is the hypothalamus located?
below thalmus
68
what is the function of the hypothalamus?
- A principle autonomic center of the brain; helps to control the sympathetic and parasympathetic nervous systems
- helps to control the activity of the pitutiary gland (feeding behavior, temperature regulation, emotions, etc.)
69
where is the epithalamus located?
above the thalamus
70
What does the epithalamus include?
pineal gland
71
Where is the subthalamus located?
under the thalamus and posterior to the hypothalamus
72
what is the function of the subthalamus?
includes the subthalmic nucleus that is involved in motor pathways
73
what is the telencephalon?
cerebral hemispheres
74
what are the right and left cerebral hemispheres separated by?
longitudinal cerebral fissure
75
what is the gray matter in the telencephalon organized as?
cerebral cortex
| corpus striatum
76
what is the cerebral cortex
made of mostly gray matter and covers the surface of each hemisphere
77
What is the corpus striatum?
striped body
- nuclei located deep in (at the base of) each hemisphere
- important in motor control functions
78
what is the white matter of the tenecephalon organized as?
Medullary center or core
79
What three types of fibers comprise the medullary center (white matter)
- association fibers/axons
- commissural fibers
- projection fibers
80
what are association fibers?
connect different cortical areas within a single hemisphere
81
what are commissural fibers?
connect a cortical area of one hemisphere to a (similar) cortical area of the opposite hemisphere
82
do commissural fibers decussate from one hemisphere to the other?
Yes commissural fibers decussate or cross from one hemisphere to the other
83
what is a projection fiber?
connects an area of cerebral cortex to a subcortical area or a subcortical area to a cerebral cortical area
84
what is an internal capsule?
many projection fibers that converge to form a compact zone of axons which are positioned deep in each hemisphere
85
what is the importance of projection fibers?
used for majory sensory and motor pathways and can be damaged in strokes
86
what are gyri?
a series of folds formed by highly convoluted surface of the cerebral hemispheres
87
what is a sulci?
The grooves or furrows that intervene between adjacent gyri
88
what are the five anatomical lobes of each cerebral hemisphere?
```
frontal lobe
parietal lobe
temporal lobe
occipital lobe
Insula or island of Reil
```
89
what is the ventricular system of the brain?
Seires of fluid-filled spaces within the brain that is derived from the neural canal of the embryonic neural tube
90
What lines the ventricular system of the brain?
ependymal cells
91
What does the ventricular system contain?
Choroid plexus
92
What does the choroid plexus secrete?
Cerebral spinal fluid
93
Where does CSF go after being circulating in the ventricles?
Circulates out of the ventricles into the subarachnoid space around the brain and spinal cord.
94
Where is CSF resorbed?
Arachnoid villi into the superior sagittal venous sinus
95
What is the total volume of CSF?
80-150 ml
96
How much of the 80-150 ml fills the ventricular spaces?
About 1/3
97
How much CSF is produced per day?
600 ml per day that is constantly produced and resorbed
98
What are the lateral ventricles?
paired chambers within each cerebral hemisphere and includes the choroid plexus
99
What are the parts of the lateral ventricle?
```
Anterior horn (frontal lobe)
Body (pre/post central gyri)
Posterior horn (occipital lobe)
Inferior horn (temporal lobe)
Collateral trigone (where body, posterior horn and inferior horn intersect)
```
100
What is the III ventricle?
Unpaired space between the two halves of the diencephalon (includes the choroid plexus)
101
What is the interventricular foramina (of Monro)
Paired; connects each latern ventricle (anterior horn) to the II ventricle
102
What is the cerebral Aqueduct (of Sylvius)
ventricular canal that resides within the midbrain; connects the III ventricle to the IV ventricle
103
What is the IV ventricle?
Unpaired chamber; includes some choroid plexus
104
What forms the roof of the IV ventricle?
Cerebellum
105
What forms the floor of the IV ventricle?
Pons and Medulla
106
What is another name for the floor of the IV ventricle?
Rhomboid fossa
107
What are the lateral aperatures (foramina of Luschka)?
Paired; connects the IV ventricle to the subarachnoid space
108
What is the pontine cistern?
Subarachnoid space on ventral aspect of pons.
| Located at pontomedullocerebellar angle
109
What is the median aperature?
Unpaired; connects the IV ventricle to the subarachnoid space (Cisterna magna)
110
What is the cisterna magna?
Subarachnoid space between medulla and cerebellum
| Dorsal to the medulla
111
What is another name for the cisterna magna?
Cerebellomedullary cistern (between medulla and cerebellum)
112
Trace the CSF circulation starting at the lateral ventricle
Lateral ventricle -> foramen of monro -> III ventricle -> cerebral aqueduct -> IV centricle -> lateral and median apertures -> subarachnoid space -> reabsorbed at arachnoid villi -> dural venous sinus
113
What is hydrocephalus?
Excess CSF, often related to increases CSF pressure
114
What is obstructive hydrocephalus?
Obstruction of CSF criculation out of ventricles -> ventricular hypertrophy (increased CSF upstream of obstruction)
115
What is communicating hydrocephalus?
Excess CSF in entire system (internal and external to the brain)
Often due to poor resorption or over secretion
116
What is external hydrocephalus?
Increased CSF in subarachnoid space
| Common in senile dementia
117
What is the clinical significance of hydrocephalus?
Increased cranial pressure can result in structural and functional damage
- Neurological defects and excruciating head aches
118
What is papilladema?
Swelling of the optic disc
119
What is the caudate nucleus?
Paired
| Nucleus involved in motor control that lies along the lateral ventricle
120
What is the head of the caudate?
In the lateral wall of the anterior horn of the lateral ventricle
121
What is the body of the caudate?
In the lateral wall of the body of the lateral ventricle
122
What is the tail of the caudate?
In the roof of the inferior horn
123
What is the amygdala?
almond sized and shaped nuclear complex
124
Where is the amygdala found?
Positioned just beyond the tip of the inferior horn and the tail of caudate in the temporal lobe
125
What is the function of the amygdala?
It is a limbic structure
| - involved in emotions, behavior, autonomic and endocrine chages
126
What is the hippocampus?
Gray matter structure (cortex) that is involved in memory and emotions
127
Where is the hippocampus found?
Lies along the floor of the inferior horn of lateral ventricle (in the temporal lobe)
128
What is the fornix?
Major tract of white matter fibers that emerge from the hippocampus and projects largely to the diencephalon (mammary body and hypothalamus)
129
What is the function of the fornix?
interconnects limbic system structures
130
What is the corpus striatum?
Gray matter positioned dee in each hemisphere; involved in motor control
131
What are the two nuclei of the corpus striatum?
Caudate nucleus
| Lenticular nucleus
132
What are the two parts that make up the lenticular nucleus?
```
globus pallidus (medial)
putamen (lateral)
```
133
What is the internal capsule?
White matter structure that consists of projection fibers that provide connections to and from neurons of the cerebral cortex
134
What are the 3 parts of the internal capsule?
anterior limb
Genu
Posterior limb
135
What is the anterior limb of the internal capsule?
Separates caudate from the lenticular nucleus
136
What is the genu of the internal capsule?
"knee between anterior and posterior limbs
137
What is the posterior limb of the internal capsule?
Lenticulothalamic portion
138
What is the clinical significance of the internal capsule?
Can be damaged in strokes
139
What is the septum pellucidum
Partition like structure that separates the anterior horns of the lateral ventricles
140
What is the interthalamic adhesion or massa intermedia?
Gray matter bridge that connects two halves of the thalamus
