L16: Motor Cortices - A Flashcards
Which two structures are important for external cues?
Which structures is important for internal cues?
External
- PMA/C
Internal
-SMA
____ program is considered to be the “how” of movements while the ____ program is considered to be the “when” of movements
Praxic Programs =
how
Intentional Programs = when
True or False: The Praxic Programs are associated with the basal ganglia while the Intentional Programs are associated with the cerebral cortical areas
False - Praxi Programs are associated with Cerebral Cortical areas;
Intentional Programs are associated with Basal Ganglia
True or False: Midcourse corrections of movements are possible and involve cerebellar circuitry
True
_____: Neurons that innervate skeletal muscles (form motor end plates)
A. Upper motor neurons
B. Lower motor neurons
B. Lower motor neurons
Neurons in Layer V of ___ give rise to axons that contribute to the CST
A. SMA
B. PMA
C. PMC
D. M-I
E. FDF
D. M-I
True or False: Hands and face (areas important for precision and fine control) have disproportionately large representation in motor map
True
Where do neurons in Layer V of M-I–which give rise to axons that contribute to the CST–terminate?
Ventral horn of all levels of the spinal cord
Main function of the CST?
Activate neurons in ventral horn (innervates distal musculature)
Which of the following activates fine, distal movements around a SINGLE joint?
A. SMA
B. PMA
C. PMC
D. M-I
E. FDF
D. M-I
True or False: Electrical threshold for eliciting movement is lower in M-I than in any other part of the cerebral cortex
True
M-I is kept informed about position of limb and speed of movement through which two sensory input?
1) Thalamus –thalamocortical connections
2) S-I – corticocortical connections
True or False: Although the PMC is x6 larger than M-I, it only contributes a small portion to the CST
True
Which of the following structures plays a role in planning and setting the stage for a motor task?
A. SMA
B. PMA
C. PMC
D. M-I
E. FDF
C. PMC
True or False: Activity in PMC is increased with initiation of a motor task
False - activity in PMC is DECREASED with initiation of a motor task
Transformation and integration of sensory information into motor programs is an important function of both the ___ and the ____
PMC and PMA
Coordinated movement of the limbs (contraction of muscles at more than 1 joint) can be elicited by stimulating the ____
A. PMC
B. PMA
C. M-I
C. SMA
A. PMC
True or False: Compared to the M-I, movements by the PMC are faster than those seen after M-I stimulation and more likely to involves smaller groups of muscles
False - compared to M-I, movements by the PMC are SLOWER than those seen after M-I stimulation and more likely to involves LARGER groups of muscles
True or False: Both the PMC and SMA contain motor homunculus, but one that is not as precise as M-I
True
True or False: Stimulation of SMA produces complex motor movements and coordinates movement on both sides of the body
True
True or False: Threshold for movements is higher in the SMA compared to the M-I
True
Action of proximal m occurs directly via corticospinal projections from the ____ to the ventral horn of the spinal cord
A. M-I
B. SMA
C. PMC
D. PMA
B. SMA
Action of distal muscles occurs indirectly via connections from the __ to ___
SMA to M-I
True or False: SMA neurons appear to inhibit M-I neurons and RETAIN learned motor programs
False - while the SMA does appear to RETAIN learned motor programs, SMA neurons appear to excite M-I neurons
What is the main input to the PMA?
Primary somatosensory (S-I) cortex
In which area is neuronal activity modulated by states of attention?
PMA
PMA can be driven by sensory stimuli, but only in context of specific behavioral responses – ___ ____ activities
goal-oriented
Which of the following is involved in initiation of rapid horizontal eye movements (saccades)?
Frontal Eye Fields
True or False: Stimulation of the S-I (Primary Somatosensory cortex) and the PFC elicits motor movements
False - does NOT elicit movement
The S-I contributes fibers to the CST, which terminate in the ____ ____ of the SC and, therefore, are in a position to modulate incoming sensory info before it reaches consciousness
dorsal horn
Lesions of S-I may cause what appear to be motor deficits – but deficits are not due to motor dysfunction. They are actually caused…?
Lack of sensory information reaching motor areas
One has a lesion in PFC. What symptoms/behaviors are to be expected?
1) More distracted
2) Lack of motivation
