Ch.11, Motor and Somato Control Flashcards
how does somatosensory info contribute to the motor system in 3 levels
- spinal cord = motor reflexes
- brainstem = motor timing and control, species typical movements, posture, walking = AUTOMATIC CONSCIOUS
cerebrum= conscious control of movements
Process of hierarchical ands paralell movement control
- need visual input
- frontal-l;obe motor areas plan the reach and command movement
- spinal cord carries info to hand or some other area
- motor neurons carry message to muscles
- = sensory receptors report back to cortex saying that movement has been completed
BACK UP TO BRAIN - spinal cord carries sensory info to the brain
- basal ganglia facilitates grasp force needed and cerebellum corrects movement errors
= sensory cortex receives the message that thee action is complete
NMJ
neuromuscular junction, pre is axon terminal, post is end plate (specialized area containing receptors)
- facilitates VOLUNTARY movement
-uses AcH
-Somatic nervous system
AcH binds to ligand gated (ionotrophic receptors) for the influx of Na+ = net depolarization
order of nerves down the spinal cord
CTLSC
Cranial
Thoracic
Lumbar
Sacral
Coccygeal
each never has a corresponding dermatome
each nerve has a bilateral nerve
Law of bell and magendie
afferent: enters posterior root ganglion of the spinal cord
efferent: leaves the anterior root ganglion of the spinal cord, going to muscle cells after white matter fiber tracts have communicated with the brain (Dermatome)
Matter organization of the dermatome
gray matter inside, white matter outside: OPPOSITE OF FOREBRAIN
PRG
posterior root ganglion; collection of cell bodies outside CNS
How are layers of the motor cortex different from layers of the sensory cortex?
Motor cortex and sensory cortex both integrate at layers I, II, and III
BUT sensory cortex has a MUCH LARGER LAYER IV= primary job is to receive (afferent) incoming sensations
Layer Iv also receives in motor cortex, but it has a MUCH LARGER LAYER V AND VI= primary job is for output (efferent) to muscle cells
Other names for motor cortex
M1
Primary motor cortex
Precentral gyrus (anterior nto the central fissure)
Frontal lobe
other names for sensory cortex
postcentral gyrus: posterior from central fissure
S1
Motor sequence
movement “modules” pre programmed by the brain created so that movements can be produced as a unit: movement is not “Seperate” bits, its a whole unit so that way actions can be fluid and happen much quicker
As one sequence is being executed, the next sequence is being prepared to follow the first smoothly
Pathway to intiate a motor sequence
- Prefrontal cortex plans a movement (PFC does not specify precise movements to be made, but makes a decision about what goal to select)
- Premotor cortex sequences: organizes order of movement
- motor cortex executes proper action
Premotor cortex lesions, peanut task and monkeys
when premotor cortex is lesioned, monkeys can’t sequence their actions to properly carry out the three steps needed to grab the food from the location
pincer grip vs whole hand group
pincer= precision
whole hand = power grip
areas of the brain activated during simple movement, movement sequence, and complex movement
Simple movement: only M1 and S1
Movement sequence: M1, S1, and dorsal premotor cortex (bc that’s plans the movement sequence)
Complex movement: PFC for planning, M1, S1, temporal for memory and spatial navigation of a maze, parietal (dorsal) stream
brainstem
species typical movement, INNATE actions that you don’t have to learn, usually adaptive to the environment
Brainstem and cortex
animal studies show that just stimulation of brainstem can cause species specific behavior like a specific fear response to activate, but context also matters: providing an actual ecological threat makes the reaction extreme when it is coupled with continued stimulation of brainstem,
Quadriplegia, results, cause=s
means damage occured somewhere at the C1 C2 level: now all areas under here can’t receive or send to the brain
means that arms and legs are paralyzed
