11.1 Flashcards
Hierarchical and Parallel Movement Control
What is somatosensory information that travels INTO the SNS from the body called?
Afferent information
What is somatosensory information that travels OUT of the SNS into the body called?
Efferent information
How does the spinal cord connect the somatosensory and motor systems?
Through the central nervous system
In a cross-section view of the spinal cord, what area sends sensory information?
Posterior tracts
In a cross-section view of the spinal cord, what area sends motor information?
Anterior tracts
What is a posterior root?
The point where SNS nerves merge into a bundle of fibers and enter the spinal cord
What is an anterior root?
The point where a fiber bundle leave the spinal cord’s anterior side and carry information out from the spinal cord to the muscles.
How is the basal ganglia involved in motor action?
Gauges amount of force needed to complete a movement
How is the cerebellum (in the brainstem) involved in motor action?
Regulates the movement’s timing and accuracy
What is a motor sequence?
Movement modules preprogrammed by the brain and produced as a unit
What are the three regions of the frontal lobe involved in movement, from front to back?
Prefrontal cortex, premotor cortex, primary motor cortex
What is the role of the prefrontal cortex in movement?
It plans complex behavior (doesn’t specify what movements to make);
It thinks about the abstract plan needed to complete a goal.
Makes the decision on which goal to select
What is the role of the premotor cortex in movement?
Organizing and coordinating complex movement sequences (think of the monkey with the food on the table)
What is the role of the primary motor cortex (M1) in movement?
Producing focal skilled (precise) movements, action initiation, sending the body signals to execute motor sequence
What happens to a person if there is damage to M1?
They will have difficulty reaching and shaping fingers to perform various hand grasps, difficulty speaking (moving lips and tongue)
What happens to a person is there is damage to the anterior prefrontal cortex?
They may have difficulty planning or deciding upon a task
What is an example of parallel organization?
The fact that we can make a variety of plans and make whole-body or discrete movements independently of each other (e.g. talking and walking and picking up a glass)
What role does the brainstem play in movement?
It controls species-typical behaviors (innate behaviors)
What is locked-in syndrome?
A condition in which a patient is aware and awake but cannot move or communicate verbally because of complete paralysis of nearly all voluntary muscles expect the eyes
What causes locked-in syndrome?
Damage to the brainstem
What are three key observations from experimenting with species-typical behavior?
- The brainstem controls species-typical behaviors
- Species typical behaviors are complex and coordinated
- Species-typical behaviors are adaptive
What is cerebral palsy?
A disorder primarily of motor function, in which making voluntary movements becomes difficult, while many aspects of conscious behavior controlled by the cortex may remain intact
What is often the cause of cerebral palsy?
Damage to the brainstem before or shortly after birth
What is quadriplegia?
Paralysis and loss of sensation in arms and legs (damage to cervical region of spinal cord)
What is paraplegia?
Paralysis and loss of sensation confined to legs and lower body (injury to spinal cord below cervical nerves)
What kind of sensory information can sometimes remain intact in cases of complete quadreplegia?
The sense of pain
Spinal reflexes still function too
What is the scratch reflex?
An automatic response in which an animal’s hind limb reaches to remove a stimulus from the surface of the body
The CNS regions and pathways involved in motor control display both a(n) ________ and a(n) _________ arrangement
Hierarchical; parallel
The ________ cortex plans movements, the _______ cortex organizes movement sequences to carry out the plan, and the ______ cortex executes precise movements
Prefrontal; premotor; motor (M1)
The ________ is responsible for species-typical movements, for survival-related actions, and for posture and walking
Brainstem
In addition to serving as a pathway between the brain and the rest of the body, the _________ independently produces reflexive movements
Spinal cord
Explain what happens when the brain is disconnected from the spinal cord and why.
Lower-level functions in the motor hierarchy can continue in the absence of higher-level ones, but the higher levels provide voluntary control over movements. When the brain is disconnected from the spinal cord, movement can no longer be controlled at will.
