8 The Control of Movement Flashcards
Control movement of the body in relation to the environment
Skeletal or striated muscles
Controls digestive system and other organs
Smooth muscles
Heart muscles that have properties of skeletal and smooth muscles
Cardiac muscles
A synapse between a motor neuron axon and a muscle fiber
Neuromuscular junction
Oppose each other
Flexor muscles
Extensor muscles
Antagonistic muscles
Produce fast contractions but fatigues rapidly
Fast-twitch fibers
Produce less vigorous vibration without fatigue
Slow-twitch fivers
Slow twitch fibers are ____ and require oxygen during movement and therefore do not fatigue
Aerobic
Does not use oxygen at the time
Fast twitch fibers
Anaerobic
Receptor that detects position movement of a part of the body
Proprietor
Occurs when muscle proprioceptors detect the stretch and tension of a muscle and send a message to the spinal cord to contract it
Stretch reflex
Receptor parallel to the muscle that responds to a stretch
Causes contention of the muscle
Muscle spindle
Respond to increases in muscle tension
Acts like a “brake” by sending an impudent to the spinal cord
Golgi tendon organs
Involuntary, consistent, automatic, responses to stimuli
Reflexes
Movements that once initiated, cannot be altered or corrected
Ballistic movement
Neural mechanisms in spinal cord that generate rhythmic patterns of motor output
Central pattern generators
A fixed sequence of movements
Motor program
Put your finger near a baby it will try to grab it
Grasp reflex
If you rub the bottom of a baby’s foot it will spread its toes
Babinski reflex
If you put your finger on a baby’s cheek it will turn its head toward if
Rooting reflex
Keeps track of the position of the body relative to the world
Posterior parietal cortex
Stores sensory information relevant to a movement and also plans movement according to their probable outcomes
Prefrontal cortex
Damage to prefrontal cortex
Can’t plan well, disorganized
Most active immediately before a movement. When you intend to move
Received info about a target to which the body is directing it’s movement as well as info about the body’s current position and posture
Premotor cortex
Along with the prefrontal cortex, it important for planning and organizing rapid sequence of movement in particular orde
Supplementary motor cortex
Active both during preparations for a movement and while watching someone else preform he same or similar movement
Mirror neurons
Your motor cortex produces a ____ potential before any voluntary movement
Readiness potential
Paths from cerebral cortex to the spinal cord
Corticospinal tracts
Set of amazons from the primary motor cortex, surrounding area and the red nucleus
Lateral corticospinal tract
Includes axons from many parts of cerebral cortex
Also includes axons from the midbrain tectum, reticular formation, and the vestibular nucleus
Medial corticospinal tract
____ is important for balance and coordination but does so much more
Cerebellum
Cerebellum relieves input from spinal cord, from each of the sensory systems by way of the cranial nerve nuclei, and frontage cerebral cortex
Information eventually reaches rife cerebellar cortex
Flat cells in sequential planes
Purkinje cells
Axons parallel to one another and perpendicular to the planes of the Purkinje cells
Parallel fibers
The greater the number of excited Purkinje cells, the greater their collective duration of response
Output of Purkinje cells controls the timing of a movement
Group of large subcortical structures in the forebrain
Caudate nucleus
Putamen
Globus pallidus
Basal ganglia
Input comes to the caudate nucleus and putamen, mostly from the cerebral cortex
Output from the caudate nucleus and putamen goes to the globus pallidus and from there to the thalamus
Critical for learning new habits, motor skills, organization, “automatic” behaviors
Driving a car
Basal ganglia
Symptoms: Rigidity, muscle tremors, slow movements, difficulty initiating physical and mental activity, loss of smell
Parkinson’s Disease
Gradual progressive death of neurons
Especially in the substania nigra
Results: increase inhibition of thalamus and therefore decreased excitation of cerebral cortex
Loss of dopamine
Parkinson’s disease
Major source of dopamine
Substania nigra
Treatment to restore missing dopamine
L- Dopa
Motor symptoms usually begin with arm jerks and facial twitches and then spread to other parts of body
Gradually the tremors interfere more and more with walking speech and other voluntary movements
Huntington’s Disease
People with up to 35 CAG
Safe
36-38 CAG
Probably but not until old age
39+ CAG
Likely to get it
