Test 2: lecture 14 Telencephalon Flashcards
1
Q
5 subdivisions of the telencephalon
A
neocortex
paleocortex
archicortex
basal ganglia
basal forebrain
2
Q
lesions in the telencephlaon lead to ___ sided signs
A
contralateral (other side)
3
Q
lesions in the telencephalon lead to ___
A
•blindness, depression, seizures
4
Q
A
5
Q
fissure down the center of the two hemispheres
A
longitudinal
6
Q
fissure between the frontal and parietal lobe
A
central sulcus
ansate sulcus (sheep)
7
Q
There is a region of underlying white matter consisting of ___that carry axons from individual gyri into and out of the ____, which is the major fiber bundle attaching the telencephalon to the brainstem
A
corona radiata
internal capsules
8
Q
•There are white matter ____that connect the two cerebral hemispheres.
A
commissures
9
Q
___ is white matter that connects the two lateral hemispheres
A
corpus callosum [CoC]
10
Q
____ connects the two temporal lobes of the cerebral hemisphere across the midline
A
rostral/anterior commissure [AC]
11
Q
___ connects the pretectal nuclei, mediating the consensual pupillary light reflex
A
caudal (posterior) commissures [PC]
12
Q
what ventricles are in the telenchalon?
A
lateral ventricles
13
Q
three parts of the basal ganglia
A
striatum → caudate /putamen [PUT] (input)
globus pallidus [GP] (output)
14
Q
___participate in complex locomotor behavior and emotions
A
basal ganglia
15
Q
____ is important in memory
A
basal forebrain
16
Q
3 type of cortex in the telencephalon
A
neocortex
archicortex
paleocortex
17
Q
neocortex
A
frontal, parietal, occipital, and temporal lobes
- Most modern, largest and most developed part of the cortex
- only in mammals; 6 layers
18
Q
archicortex
A
Hippocampus
- involved in declarative memory function
- Spatial memory, cognitive map of space
- mood, reward
19
Q
paleocortex
A
Olfactory Cortex or piriform lobe
-separated from neocortex by the rhinal fissure
20
Q
layer 2-3 of the neocortex
A
to other cortical areas
local circuit, short association, long association
21
Q
____ layer of the neocortex:
to other cortical areas. local circuit, short association, long associatio
A
2-3
22
Q
___ is the input layer of the neocortex
A
layer 4
23
Q
___ layer of the neocortex
provides feedback to to subcortical areas
(spinal cord, brainstem, basal ganglia)
A
layer 5
24
Q
layer 5 of the neocortex
A
to subcortical areas
(spinal cord, brainstem, basal ganglia)
25
layer 6 of the neocortex
feedback to the thalamus
26
\_\_\_ layer of the neocortex gives feedback to the thalamus
layer 6
27
the frontal lobe has what primary receiving area?
motor (M1)
thalamic nucleus VL/VA
28
the parietal lobe has what primary receiving area?
somatic sensory (S1)
thalamic nucleus VPL/VPM
29
the occipital lobe has what primary receiving area?
visual (V1)
thalamic nucleus: LGN
30
the temporal lobe has what primary receiving area?
hearing (A1)
thalamic nucleus MGN
31
each primary receiving areas are organized
**topographically**: little body in proportion to input
32
green: **Supplementary motor area, SMA:** **Premotor area, PMA:**
area 6 • Motor Planning
orange**: P-T-O Association cortex** •Analysis of sensory inputs •Constructs representation of our sensory world
pink: **Prefrontal Association cortex:** •executive function •Abstract thought •decision making •anticipating consequences of action
33
what area is for •executive function •Abstract thought •decision making •anticipating consequences of action
prefrontal association cortex
| (pink)
34
Brodmann's area 4
M1- primary motor cortex- initiation of complex voluntary movement
corticospinal tract
35
Brodmann's area 6
**Supplementary motor area, SMA: Premotor area, PMA:**
Motor Planning
36
somatotopic organization of the primary motor cortex
37
Betz cells
found in layer 5 of the neocortex in the primary motor cortex
## Footnote
**Origin of the corticospinal tract (upper motor neuron)**
•Initiation of complex voluntary movement
* Activity in M1 neurons occurs before and during a voluntary movement.
* Activity encodes force and direction of movement
**(the more frequent firing= stronger force. Specific Betz cells for specific movements)**
38
Activity in M1 neurons occurs before and during a\_\_\_\_movement.
voluntary
Betz cells
39
lesions ____ where result in the loss of the ability to make independent finger movements
corticospinal tract
40
lesions in the corticospinal tract will cause
* Difficulty moving **distal limbs –** may recover over time
* Loss of ability to make **independent finger movements** – does not recover
41
\_\_\_\_ are involved in motor planning and send signals to M1
area 6- SMA and PMA
## Footnote
Supplementary motor area, SMA:
Premotor area, PMA:
(get set- signal to get ready to perform a specific task)
42
two main groups of descending spinal pathways from the brain
lateral pathways
ventromedial pathway
43
descending lateral pathways are:
coricospinal - distal finger movements
rubrospinal- distal
44
what are the descending spinal pathways ?
tectospinal
vestibulospinal
pontine reticulospinal
medullary reticulospinal
45
what do the descending lateral pathways control?
* Voluntary movement of distal musculature
* Under direct cortical control
* Innervate distal musculature
46
ventromedial pathways control ___ and are under __ control. They innervate __ musculature.
Control of posture, locomotion, orienting and balance
* Under brainstem control
* Innervate axial and proximal musculature
47
lateral descending pathways control ____ are under ____ control and innervate \_\_\_
Voluntary movement of **distal musculature**
* Under **direct cortical contro**l
* Innervate **distal musculature**
48
lateral spinal pathway comes from ___ area
brodman's area 4 in the frontal lobe (primary motor cortex)
**corticospinal tract**: limbs and detailed finger movement
**rubrospinal tract**: distal limb muscles
49
corticobulbar tract
(bulb=brainstem) from the cortex to the brainstem
travels with CST (in the lateral funiculus) and provides UMN innervation to LMNs in **cranial nerve motor nuclei**
Face, jaw, tongue and throat
50
corticopontine travel in the cerebral peduncles to the \_\_\_
pontine nuclei
51
orienting reflexes are caused by \_\_\_
tectospinal tract (head)
tectobulbar tract (eyes)
come from superior colliculus down the spinal cord in the ventral colliculus to the ventral horn
52
what spinal tract controls balance?
* *vestibulospinal tract**
medial: bilateral to neck
Lateral: ipsilateral to forelimb and hindlimb
from the vestibular nucleus is the medulla down the ventral funiculus to the ventral horn
53
what tract controls same side posture and locomotion
**Pontine reticulospinal tract:** ipsilateral
pontine reticular formation down the ventral medial funiculus to the intermediate zone?
54
what tract controls bilateral posture and locomotion?
medullary reticulospinal tract: bilateral
55
UMN signs of lesions
Increased tone **(spasticity)**
**Hyperactive reflexes**
Pathological reflexes
(plantar extensor or Babinski)
(upper= more tone)
56
LMN signs of a lesion
**Decreased tone**
**Hypoactive** reflexes
Weakness
Atrophy
Fasciculations
(lower= less tone/weakness)
57
hyperactive reflexes is a sign of ___ lesion
UMN
58
\_\_\_\_ and ____ act on cerebral cortex through relay nuclei in the thalamus (VL/VA)
Basal ganglia
cerebellum
59
Basal ganglia and cerebellum act on cerebral cortex through relay nuclei _____ in the thalamus
VL: ventral lateral
VA: ventral anterior
60
\_\_\_ is involved in the selection and initiation of willed movements procedural learning
basal ganglia
61
basal ganglia receives info from ___ and relays it to \_\_\_\_
cortex
VL and VA nucleus of the thalamus and up to the motor cortex to effect descending tracts that are controlling voluntary and involuntary movement
62
inputs of the basal ganglia
caudate and putamen (striatum
63
\_\_\_ is the output of the basal ganglia
globus pallidus (pallidum)
64
5 parts of the basal ganglia
Striatum: caudate/ putamen
Globus pallidus (pallidum)
Subthalamus
Substantia nigra
**involved in the selection and initiation of willed movements procedural learning**
65
direct pathway of the basal ganglia
input from cortex comes to the **putamen**
this synapses at the **globus pallidus**
**globus pallidus stops** inhibiting **the** **VL and VA nuclei in the thalamus.**
**this allows the thalamus to** impact the **somatic motor area** of the brain to effect **UMN** of voluntary and involuntary muscle movements
66
\_\_\_\_is tonically active and inhibiting the VL/VA thalamus
Globus pallidus
67
In the basal ganglia, cortex transiently excites \_\_\_\_
striatum (putamen)
striatum = putamen/caudate
(this leads to the temporary inhibition of the globus pallidus which will allow the VA and VL in the thalamus to send a signal to the Somatic motor area)
68
Putamen transiently \_\_\_globus pallidus
inhibits
69
what happens when the stiatum is stimulated
globus pallidus, which is always sending turn off signals to the VA/VL nucleus of the thalamus, will turn off. this will allow a signal from the VA/VL to go to the motor cortex
70
how does damage to substantia nigra effect the basal ganglia?
if dopaminergic cells in the substantia nigra are damaged that means it will be harder to turn off the inhibitory signal from the globus pallidus to the VA/VL in the thalamus
it will be harder to make a movement→ hypokinesis → parkinsons
71
hypokinesis
if dopaminergic cells in the **substantia nigra** are damaged that means it will be harder to turn off the inhibitory signal from the **globus pallidus** to the VA/VL in the thalamus
i**t will be harder to make a movemen**t→ hypokinesis → **parkinsons→ tremor harder to initiate a movement**
72
what happens to the basal ganglia if the subthalamus is damaged
Decreased GP output leads to **hyperkinesis e.g., Hemiballismus**
- loss of tonic inhibitory output to thalamus, cell loss in subthalamus
subthalamus increases the inhibitory action of the globus pallidus on the VL/VA of the thalamus- if you decrease the action of the subthalamus it will be easier to turn off the globus pallidus → **easier to make a movement- too big movements- huntington's chorea (constant movement)**
73
basal ganglia damage results in :
Disturbances of muscle tone (either **hypotonia or hypertonia**)
**Dyskinesias or abnormal involuntary movements**
athetosis (writhing movements)
chorea (brisk, involuntary 'dance-like’ movements of extremities)
ballismus (wild, flinging movements of the limbs)
Resting tremor (Parkinson’s Disease)
74
In animals with basal ganglia lesions the most typical disturbance
of motor activity is one of excessive locomotion--constant pacing or
\_\_\_
hyperkinesia
