Anatomy 16 Flashcards
(102 cards)
1
Q
The white matter of the brain consists of:
A
1) Association fibers
2) Commissural fibers
3) Projection fibers
2
Q
What do association fibers connect?
A
Different areas in the same hemisphere
3
Q
What do commissural fibers connect?
A
Similar areas in the 2 hemispheres
4
Q
What do projection fibers connect?
A
Fibers from and to the cerebral cortex
5
Q
What are the 2 types of association fibers?
A
1) Long
2) Short
6
Q
What do the short association fibers connect?
A
Adjacent gyri, forming U-shaped arcuate fibers in all parts of the hemisphere
7
Q
What are the types of long association fibers?
A
1) Superior longitudinal bundle
2) Inferior longitudinal bundle
3) Cingulum
4) Uncinate Fasiculus
8
Q
What does the superior longitudinal bundle connect?
A
Frontal, occipital, and temporal regions
9
Q
Where does the inferior longitudinal bundle run?
A
From the temporal to the occipital poles.
10
Q
Where does the cingulum begin and end? What does it connect?
A
Begins: Near rostrum of corpus callosum
Ends: In the uncus;
Connects them with the hippocampus and cingulate gyrus
11
Q
Where is the cingulum found?
A
As an incomplete circle around the corpus callosum
12
Q
Where does the Uncinate Fasiculus run?
A
From frontal to temporal poles
13
Q
Where do the anterior commissural fibers cross?
A
The middle line within lamina terminalis
14
Q
What do the anterior commissural fibers connect?
A
Both piriform fossae
15
Q
What is the function of the anterior commissural fibers?
A
Acute pain and smell
16
Q
Where are the posterior commissural fibers found?
A
Lower pineal stalk
17
Q
What is the function of the posterior commissural fibers?
A
Pupillary light reflex
18
Q
What do the posterior commissural fibers connect?
A
Superior colliculi and pretectal nuclei
19
Q
Where are the Habenular commissural fibers found?
A
Superior to pineal stalk
20
Q
What do the Habenular commissural fibers connect?
A
Right and left habenular nuclei
21
Q
What are the Habenular commissural fibers connected to?
A
Amygdaloid nucleus
22
Q
What is the function of the Habenular commissural fibers?
A
Center of integration of olfactory and visceral pathways
23
Q
What are the Fornix commissural fibers?
A
Efferent fibers of hippocampus
24
Q
What do the Fornix commissural fibers connect?
A
Crura and body of the fornix across both hippocampi
25
What are the 5 commissural fibers?
1) Anterior commissure
2) Posterior commissure
3) Habenular commissure
4) Fornix commissure
5) Corpus callosum
26
What is the corpus callosum?
The great (10 cm) transverse commissure
27
What does the corpus callosum connect?
The cerebral hemispheres and roofs (the lateral ventricle) (except any part of temporal lobes which are connected by the anterior commissure).
28
The corpus callosum is divided into 4 parts:
1) Rostrum
2) Genu
3) Body
4) Splenium
29
What do fibers of the Genu do?
Curve forwards to connect frontal lobes forming “Forceps minor”
30
What do fibers of the Splenium do?
Curve backwards to connect occipital lobes forming “Forceps Major”.
31
What is the Tapetum?
Fibers of body and splenium intersecting with corona radiata of the internal capsule.
32
What is the blood supply of the corpus callosum?
Anterior cerebral artery (ACA) EXCEPT the splenium by the posterior cerebral artery (PCA)
33
What do lesions in the corpus callosum cause?
1) Callosal Syndrome (split brain)
| 2) Apraxia
34
What are the projection fibers TO the cortex?
All thalamo-cortical fibers (thalamic radiation):
1) Sensory radiation
2) Anterior thalamic radiation
3) Visual radiation
4) Auditory radiation
35
Where does the Sensory radiation run?
From PLVNT to area 3,1,2 in the postcentral gyrus
36
Where does the Anterior thalamic radiation run?
From anterior thalamus to cingulate
37
Where does the Visual radiation run?
From lateral geniculate body to the visual area 17 in the occipital lobe
38
Where does the Auditory radiation run?
From the medial geniculate body to the auditory area in the temporal lobe
39
What are the projection fibers FROM the cortex?
1) Pyramidal tract
2) Extrapyramidal tracts
3) Cortico-pontine fibers
4) Cortico-thalamic fibers
40
What is the internal capsule?
A V-shaped bundle of projection fibers between the thalamus, caudate, and lentiform nuclei.
41
Where does the internal capsule lie?
On medial surface of lentiform nucleus separating it from caudate above and thalamus below.
42
Where is the internal capsule continuous?
1) Above as corona radiata
| 2) Below with crus cerebri of midbrain
43
What is the internal capsule divided into?
1) Anterior limb
2) Genu
3) Posterior limb
4) Retrolentiform
5) Sublentiform
44
What does the anterior limb of the internal capsule contain?
1) Descending Frontopontine (fronto-ponto-cerebellar) fibers
| 2) Ascending Thalamocortical (Anterior thalamic radiation) fibers
45
Where do the Descending Frontopontine (fronto-ponto-cerebellar) fibers project from ?
The frontal cortex to pons
46
What do the Ascending Thalamocortical (Anterior thalamic radiation) fibers connect?
The thalamus to the frontal lobes and cingulate gyrus
47
What does the genu contain?
Corticobulbar fibers which run between the cortex and
| the cranial nuclei in the brainstem.
48
What does the posterior limb of the internal capsule contain?
1) Descending anterior half Corticospinal fibers
| 2) Ascending posterior half Sensory fibers (superior thalamic radiation)
49
Where do the Descending anterior half Corticospinal fibers go?
From motor area 4 to AHCs in the spinal cord
50
Where do the Ascending posterior half Sensory fibers (superior thalamic radiation) go?
From VP of thalamus to post central gyrus
51
What does the retrolenticular part contain?
Fibers of the optic radiation (posterior thalamic radiation)
52
What does the sublenticular part contain?
The auditory radiation (Inferior thalamic radiation).
53
What does a lesion in the internal capsule cause?
Arterial/cerebral hemorrhage in high blood pressure patient (contralateral side)
54
What is the blood supply of the anterior limb?
Striate branches of:
1) Anterior cerebral artery (including the longest branch: Recurrent artery of Heubner)
2) Middle cerebral artery
55
What is the blood supply of the genu?
Striate branches of:
1) Anterior cerebral artery
2) Middle cerebral artery
+ Direct branches from the Internal carotid.
56
What is the blood supply of the posterior limb?
Striate branches of:
1) Middle cerebral artery (including large Charcot artery of cerebral hemorrhage)
2) Anterior choroidal artery
57
What is the blood supply of the sublentiform part?
Striate branches of:
1) Posterior cerebral artery
2) Anterior choroidal artery
58
What is the blood supply of the retrolentiform part?
Striate branches from the Posterior cerebral artery
59
What are the functions of the basal ganglia?
1) Voluntary movement
| 2) Postural control
60
What are the voluntary movement functions of the basal ganglia?
1) Initiation of movement
2) Change from one pattern to other
3) Programming and correcting movement while in progress
4) Learning skills (football,drawing,singing,…)
61
What are the postural control functions of the basal ganglia?
1) Automatic associated movement (walking, dancing)
| 2) Control axial and girdle movements
62
True or false:
| The basal ganglia directly connects with the spinal cord and brain stem.
False; there is NO direct connection
63
What are the subdivisions of the basal ganglia?
1) Neostriatum or Striatum
2) Pallio striatum or Pallidum
3) Lentiform nucleus
4) Archistiatum
5) Substantia nigra
6) Subthalamic nucleus
7) Claustrum
64
What are the divisions of the Neostriatum or Striatum?
1) Putamen
| 2) Caudate nucleus
65
What are the divisions of the Pallio striatum or Pallidum?
Globus pallidus
66
What are the divisions of the Lentiform nucleus?
1) Putamen lateral
| 2) Globus Pallidus medial
67
What are the divisions of the Archistiatum?
Amygdala
68
What is the Caudate nucleus made up of?
1) C-shaped
| 2) Head, body, tail (Large head, tapering curved tail)
69
Where are the parts of the caudate nucleus found?
1) Head: frontal lobe
2) Tail: occipital lobe
3) End of tail: temporal lobe
70
Where does the caudate nucleus terminate?
In amygdaloid nucleus (roof of inferior horn of lateral ventricle)
71
What does the head of the caudate nucleus form (lie?)?
The floor and lateral wall of anterior horn of the lateral ventricle
72
What does the body of the caudate nucleus form?
The floor of central part of the lateral ventricle
73
What does the tail of the caudate nucleus form (lie?)?
The roof of the inferior horn of the lateral ventricle
74
What is the lentiform nucleus?
A lens-like nucleus
75
What are the 2 parts of the lentiform nucleus?
1) Putamen: Large lateral dark part
2) Globus Pallidus: Small medial pale part
(Subdivided into external and internal segments)
76
What is the lentiform nucleus surrounded by?
1) External capsule (laterally) = separating it from claustrum
2) Internal capsule (medially)
= separating it from thalamus and caudate nucleus
77
Where is the amygdaloid nucleus located?
In the temporal lobe (uncus)
| connected to caudate tail.
78
What is the function of the amygdaloid nucleus?
Part of the limbic system functionally = sense of fear and smell
79
What does the amygdaloid nucleus give?
Axons of stria terminalis that curves on superior surface of thalamus and ends in hypothalamus.
80
Where is the substantia nigra located?
Midbrain anterior to aqueduct
81
What are the parts of the substantia nigra and their functions?
1) Pars compacta = Dopamine/inhibitory
| 2) Pars reticulata = Output to brain
82
What is found in the subthalamic nuclei and what is its function?
Diencephalon = Glutamine/excitatory
83
Where is the claustrum found and what is its function?
Lateral to lentiform nucleus. Lies between external and extreme capsules; unknown function.
84
What is the blood supply of the anterior part of corpus striatum?
Anterior cerebral artery
85
What is the blood supply of the posterior part of corpus striatum?
Middle cerebral artery
86
What is the blood supply of the tail of caudate and amygdaloid?
Anterior choroidal of internal carotid artery
87
What are the connections of the basal ganglia that receive input?
1) Caudate nucleus
2) Putamen
(Corpus striatum)
88
What are the connections of the basal ganglia that gives the output?
Globus Pallidus
89
What are the diseases of the basal ganglia?
1) Hypokinesia + hypertonia (Lesion of direct pathway)
| 2) Hyperkinesia (Lesion of indirect pathway)
90
What is an example of a Hypokinesia + hypertonia disease?
Parkinsonism
91
What causes Parkinson's disease?
Degeneration of dopamine = depletion of dopamine in striatum
92
Where are the dopamine-producing cells found?
In substantia nigra
93
What are the symptoms of Parkinson's?
1) Resting tremor (N.B: intention tremor in cerebellar disease)
2) Rigidity: simultaneous contraction of flexors and extensors
3) Bradykinesia: Slowness of movement (slurred speech) and mask face
4) Postural disturbance
5) NO loss of motor or sensory function
94
How is Parkinson's disease treated?
L-Dopa NOT dopamine
95
What are some examples of hyperkinetic diseases?
1) Huntington's disease
2) Sydenham's Chorea
3) Hemiballism
96
What is Huntington's disease?
(hypotonia+hyperkinesia) Hereditary disease of unwanted movements
97
What causes Huntington's disease?
It results from degeneration of the caudate and putamen
98
What does Huntington's disease cause?
Choreoathetosis: Continuous dance-like movements of the face and limbs
99
What can cause Sydenham's Chorea?
Rheumatic fever
100
Sydenham's Chorea is __ and those affected are expected to:
Transient; make a full recovery
101
What is Hemiballism?
Flailing movements of one arm and leg (onesided)
102
What causes Hemiballism?
Damage (ex. stroke) of the subthalamic nucleus.
