Chapter 40: Motor Cortex Flashcards

1
Q

The frontal lobe of the cerebrum is separated from the temporal lobe by the _____.

A
  • Lateral fissure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

One can see that three sulci demarcate 2 vertical gyri at the interface of the _____ and _____ lobes.

A
  • Frontal

- Parietal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

From anterior to posterior, the sulci are the precentral sulcus, the _____, and the postcentral sulcus.

A
  • Central sulcus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The central sulcus separates the _____ from the _____.

A
  • Frontal lobe

- Parietal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The precentral gyrus is between the _____ and the _____.

A
  • Precentral sulcus

- Central sulcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The primary motor cortex (Brodmann area 4) occupies the precentral gyrus which is the only vertical gyrus of the _____.

A
  • Frontal lobe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The primary motor cortex (Brodmann area 4) contains the _____ neurons for voluntary motor activity.

A
  • Upper motor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The giant motor neurons of the primary motor cortex (Brodmann area 4) are the same size as Purkinje cells (100 um across), but they are pyramidal instead of _____.

A
  • Oval (ellipsoidal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Giant pyramidal neurons (Betz cells) are found only in the _____.

A
  • Primary motor cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Brodmann defined area _____ as the area of the cerebral cortex containing giant pyramidal neurons.

A
  • 4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The axons of the giant pyramidal neurons descend in the lateral and anterior _____ tracts and synapse on lower motor neurons.

A
  • Corticospinal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The only axons in the corticospinal tracts that synapse on the dendrites and bodies of lower motor neurons are the axons of _____.

A
  • Giant pyramidal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The axons of the large (not giant) pyramidal neurons of the primary motor cortex also descend in the _____, but they synapse on internuncial neurons that synapse on lower motor neurons.

A
  • Corticospinal tracts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The giant pyramidal neurons (100 um across) of Brodmann area _____ are almost twice as large as the large pyramidal neurons (60 um across).

A
  • 4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The axons of giant pyramidal neurons synapse on _____, but the axons of the more numerous large pyramidal neurons synapse on _____.

A
  • Lower motor neurons

- Internuncial neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Both kinds of _____ are somatotopically arranged with neurons controlling the larynx at the inferior end of the precentral gyrus.

A
  • Upper motor neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The upper motor neurons controlling the tongue are superior to neurons controlling the larynx in the _____ gyrus.

A
  • Precentral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Upper motor neurons controlling the facial muscles are superior to neurons controlling the tongue in the _____.

A
  • Precentral gyrus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

_____ controlling fingers are arranged in an ascending 1-5 sequence from the _____ for the facial muscles.

A
  • Upper motor neurons

- Upper motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Upper motor neurons for the arm are _____ to the upper motor neurons for the fingers and _____ to upper motor neurons for the trunk. which occupy the peak of the precentral gyrus.

A
  • Superior

- Inferior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Upper motor neurons for the _____ are in a descending thigh-calf-foot sequence on the part of the precentral gyrus inside the longitudinal fissure.

A
  • Lower extremity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

On the motor homunculus below, each body part of the homunculus is positioned next to the region of the precentral gyrus containing the _____ neurons controlling that part.

A
  • Upper motor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The motor homunculus for a precentral gyrus has only half of a body because the left motor cortex controls only the _____ side of the body.

A
  • Right
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The disproportionate amount of space in the _____ devoted to the upper motor neurons for the _____ reflects number of neurons necessary to achieve fine motor control of the _____.

A
  • Precentral gyrus
  • Fingers
  • Fingers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
The motor homunculus is drawn next to a tilted coronal section of the cerebrum because the _____ gyrus is not perfectly vertical.
- Precentral gyrus
26
A _____ is a convenient mnemonic for the positions of the upper motor neurons controlling each body part.
- Motor humunculus
27
Upper motor neuron lesions cause _____.
- Spastic paralysis of the hands
28
The axons of the upper motor neurons pass between the thalamus and the lenticular nucleus to form the posterior limb of the _____.
- Internal capsule
29
The inferior to superior arrangement of the upper motor neurons becomes an anterior to posterior arrangement of the axons in the _____ limb of the _____.
- Posterior limb | - Internal capsule
30
The posterior limb of the internal capsule slants from _____ to _____ as it slants from anterior to posterior.
- Medial | - Lateral
31
The medial to lateral arrangement of the corticobulbar and corticospinal tracts is exaggerated as the axons pass from the posterior limb of the internal capsule to the _____ of the midbrain.
- Crus cerebri
32
The corticobulbar fibers that control the facial and laryngeal muscles part company with the _____ fibers in the pons and medulla.
- Corticospinal
33
The medial to lateral order of the corticospinal fibers is maintained through the base of the pons and the _____ of the medulla.
- Pyramid
34
When the corticospinal fibers cross in the _____, the most lateral fibers cross furthest.
- Pyramidal decussation
35
The axons of the upper motor neurons for the muscles of the _____ do not cross.
- Trunk (back)
36
Because the most lateral fibers cross furthest, the fibers that were most lateral in the pyramids of the medulla remain the most lateral in the _____ of the spinal cord.
- Lateral corticospinal tract
37
The premotor cortex (Brodmann area 6) is just anterior to the primary motor cortex in the _____ lobe.
- Frontal
38
Brodmann area 6 abuts the anterior edge of area _____ because Brodmann numbers are based on cytoarchitecture rather than position.
- 4
39
The somatotopic arrangement of area 6 follows the _____ of area 4.
- Somatotopic arrangement
40
Because the premotor cortex instructs the primary motor cortex in the performance of skilled tasks, the premotor area for the _____ is larger than the other premotor areas.
- Hand
41
Damage to the premotor cortex causes apraxia, loss of a _____ one once had.
- Skill
42
The premotor cortex receives _____ input from the _____ nucleus of the _____.
- Stimulatory - Ventral anterior - Thalamus
43
Projections of the _____ of the thalamus assist the premotor cortex in the initiation and rapid execution of _____.
- Ventral anterior nucleus | - Skilled tasks
44
The primary motor cortex is assisted by direct input from the premotor cortex and the _____ of the _____.
- Ventrolateral nucleus | - Thalamus
45
The cerebellum influences the primary motor cortex through its projections to the _____ of the _____.
- Ventrolateral nucleus | - Thalamus
46
Damage to the pontocerebellum or the pontine part of the superior cerebellar peduncle causes _____ in the _____ extremities.
- Clumsiness (apraxia) | - Ipsilateral
47
Damage to or the ventrolateral nucleus of the thalamus causes _____ in the _____ extremities.
- Clumsiness (apraxia) | - Contralateral
48
Damage to the primary motor cortex causes _____ of the muscles whose upper motor neurons are damaged.
- Spastic paralysis
49
The lower motor neurons for the extraocular muscles are in the _____, _____, and _____ nuclei.
- Oculomotor - Throchlear - Abducens
50
The _____ for the extraocular muscles are in the frontal eye field (Brodmann area 8), a triangular region anterior to the arm and trunk regions of the premotor cortex.
- Upper motor neurons
51
Brodmann area 8 is anterior to the superior part of area _____.
- 6
52
The _____ are responsible for conscious tracking movements of the eyes.
- Frontal eye fields
53
The _____ are responsible for unconscious tracking movements of the eyes.
- Superior colliculi
54
Both the frontal eye fields and the superior colliculus depend on feedback from the _____ cortex in order to track a moving object accurately.
- Parietal association
55
The primary motor cortex depends on feedback from the _____ when working in the dark or out of the line of sight.
- Parietal association cortex
56
The intensity of muscular effort depends mostly on feedback through the _____, but the location of muscular effort depends mostly on feedback from the visual cortex and _____.
- Cerebellum | - Parietal association cortex
57
The frontal lobe is separated from the parietal lobe by the _____.
- Central sulcus
58
The inferior frontal gyrus is the gyrus of the _____ lobe just superior to the _____.
- Frontal | - Lateral fissure (temporal lobe)
59
Most of the _____ above the left lateral fissure is occupied by Broca's motor speech area.
- Inferior frontal gyrus
60
The left Broca's area in the left _____ is completely dominant in male speakers of Indo-European languages.
- Inferior frontal gyrus
61
A stroke in a man's left Broca's area causes mute aphasia, the complete _____ to _____.
- Inability | - Speak
62
A stroke in a woman's left _____ causes severe loss of speaking ability because her left _____ is partially dominant.
- Broca's area | - Broca's area
63
Recovery from a stroke in the left Broca's area requires teaching the right _____ to take over the task of programming spoken language.
- Broca's area
64
Teaching a man's _____ to control speech requires about 2 years; a woman's _____ can learn in a year.
- Right Broca's area | - Right Broca's area
65
Brodmann area 8 is the _____, area 6 is the _____, | and area 4 is the _____.
- Frontal eye field - Premotor cortex (area) - Primary motor cortex
66
The primary motor cortex occupies the _____ gyrus.
- Precentral
67
The primary motor cortex gets instructions for skilled tasks directly from the _____ and indirectly from the _____ via the _____ of the _____.
- Premotor cortex - Cerebellum - Ventrolateral nucleus - Thalamus
68
Upper motor neurons are somatotopically arranged in the precentral gyrus from medial to lateral for muscles of the _____ through the _____.
- Leg (or foot) | - Larynx
69
The upper motor neuron axons are somatotopically arranged from anterior to posterior in the posterior limb of the internal capsule for muscles of the _____ through the _____.
- Face | - Leg