Motor systems are organized _______________
What two nuclei of the thalamus form the motor functional division?
VA (ventral anterior nucleus) and VL (ventral lateral nucleus)
The VA (ventral anterior nucleus) and VL (ventral lateral nucleus)are located in the ___________
The VA (ventral anterior nucleus) and VL (ventral lateral nucleus) receive what type of sensory information?
Lateral descending spinal pathways innervate (distal/medial) musculature.
(Lateral/Ventromedial) descending spinal pathways innervate distal musculature.
Lateral descending spinal pathways are responsible for (voluntary/involuntary) control of distal muscles.
Lateral descending spinal pathways are under direct control of the _________
What do lateral descending spinal pathways control?
voluntary movement of distal musculature
What do ventromedial pathways control?
posture, locomotion, orienting, and balance
Posture, locomotion, orienting, and balance are controlled by (lateral/ventromedial) descending spinal pathways.
Which descending spinal pathways are under direct control of the cortex?
Which descending spinal pathways are under brainstem control?
(Lateral/Ventromedial) descending spinal pathways innervate axial and proximal musculature.
Ventromedial descending spinal pathways innervate which muscles?
axial and proximal muscles
What are the lateral descending spinal pathways?
The corticospinal tract is a (lateral/ventromedial) descending spinal pathway.
The rubrospinal tract is a (lateral/ventromedial) descending spinal pathway.
The tectospinal tract is a (lateral/ventromedial) descending spinal pathway.
The vestibulospinal tract is a (lateral/ventromedial) descending spinal pathway.
The pontine reticulospinal tract is a (lateral/ventromedial) descending spinal pathway.
The medullary reticulosponal tract is a (lateral/ventromedial) descending spinal pathway.
What are the ventromedial descending spinal pathways?
-pontine reticulospinal tract
-medullary reticulospinal tract
The corticobulbar tract is a (lateral/ventromedial) pathway
The _______________ tract is a lateral pathway that directs movements of the face, jaw, tongue, and throat
The corticobulbar tract directs movements of what muscles?
those of the face, jaw, tongue, and throat
The corticospinal tract is also known as the ____________ tract
The ______________ tract is the lateral pathway that directs distal limb muscles and is small in humans.
The lateral spinal pathways are found in which Brodman's areas in the frontal lobe?
areas 4 and 6
The ____________ tract is the ventromedial pathway responsible for balance.
What does the vestibulospinal tract control?
What ventromedial pathways are responsible for the orientling reflexes?
tectospinal tract (head) and tectbobulbar tract (eyes)
What function do the tectcospinal and tectobulbar tracts have?
ventromedial pathways that direct the orienting reflexes (turning eyes and head toward a sudden stimulus)
Posture and locomotion are directed by which ventromedial pathways?
pontine and medullary reticulospinal tracts
The pontine and medullary reticulospinal tracts are responsible for teh control of what functions?
posture and locomotion
The soma of the corticospinal tract resides in the __________
The soma of the rubrospinal tract resides in the __________
red nucleus of the midbrain
What are the effects of corticospinal tract lesions?
-difficulty moving limbs (may recover over time)
-loss of ability to make independent finger movements (does not recover)
The loss of the ability to make independent finger movements results from a lesion in the ______________ tract
The soma of the vesitibulospinal tract resides in the __________
The soma of the tectospinal tract resides in the ___________________
The soma of the pontine reticulospinal tract resides in the ______
The soma of the medullary reticulospinal tract resides in the ___________
M1 is also known at the __________________
primary motor cortex
The primary motor cortex (M1) is Brodman area ____
Brodman area 4 is also known as _______________
M1 (primary motor cortex)
The corticospinal tract originates in which layer of the primary motor cortex?
Where are Betz cells located?
Layer 5 of primary motor cortex (M1)
Activity in M1 neurons occurs during what time points of a voluntary movement?
before and during the movement
What is a population vector?
movement direction encoded by an entire population of direction vectors
How do M1 neurons encode force and direction?
cell encodes for direction, firing rate encodes for force
The _________________ cortex detects where in space the limbs and body are located
posterior parietal cortex
The posterior parietal cortex determines what?
where the body and limbs are located in space
What sensory inputs contribute to the posterior parietal cortex?
somatosensory (SS) proprioceptors that detect location of the limbs and the "where" pathway of the visual system (M cells)
Visual area 5 of the posterior parietal cortex is also known at the ____
MT (middle temporal area)
In planning movement, the posterior parietal cortex contributes to what area of the brain and for what purpose?
prefrontal cortex for abstract thought, decision making, and anticipating the consequences of the planned action
In planning movement, what area of the brain is responsible for anticipating the consequences of the action?
What is the function of the prefrontal cortex in planning movement?
anticipates consequences of the action
The motor planning area is Brodman area ___
The motor planning area is made up of what two areas?
supplementary motor area (SMA) and premotor area (PMA)
The motor planning area receives input from what decision making area of the brain?
When would neurons in the premotor cortex be expected to fire?
while planning a movement (e.g. when a trained monkey is waiting for a light to turn on to make a movement)
What are the structures that make up the basal ganglia?
lenticular nucleus: globus pallidus/putamen
The ________________ is the output of the basal ganglia
The __________________ tonically inhibits the SMA via the VL
When the putamen is excited by the frontal cortex, it inhibits the ________________
When the __________ is excited by the frontal cortex, it inhibits the globus pallidus
What is the net effect on the SMA of inhibiting the globus pallidus?
inhibition of the globus pallidus leads to excitation of the SMA
What is the net effect on the SMA of exciting the putamen?
exciting the putamen inhibits the globus pallidus, which excites the SMA via the VL
Increasing globus pallidus output leads to (hypokinesis/hyperkinesis)
Decreasing globus pallidus putput leads to (hypokinesis/hyperkinesis)
What is hypokinesis?
slow movement, as in Parkinson's
What is hyperkinesis?
overactive movement, as in Huntington's
What causes hypokinesis?
anything that increases globus pallidus output
What causes hyperkinesis?
anything that decreases globus pallidus output (loss of tonic inhibition to thalamus)
Learning of the sequencing and timing of complex movements is done in the _____________
What information is projected to the cerebellum from the motor cortex?
What information is projected to the cerebellum from the inferior cerebellar peduncle?
actual movement (from proprioceptors)
A proprioceptor detects ______________
Information about what movements are happening is projected to the cerebellum by the ______________________
inferior cerebellar peduncle
The cerebellum compares what given information to prepare an error signal that is sent to the cortex?
compares what was intended with what actually happened and sends error signal to correct ongoing and future movements
An error signal generated by comparing an intended movement with an actual movement occurs in what part of the brain?
cerebellum (error signal is sent to cortex)
What area of the brain is responsible for planning strategies and goals of movement?
What are of the brain is responsible for the selection and initiation of movement?
What area of the brain is responsible for the sequencing, timing, and error correction of ongoing and future movement?