Chapter 8 Movemet Flashcards
Smooth muscles
Control the digestive system and other organs
Slow moving, no brain control
Skeletal muscles/ striated muscles
Control movement of the body in relation to the environment
Muscles we work out and do have control over
Cardiac muscles
Heart muscles that have properties of skeletal and and smooth muscles
Somewhat control
Neuromuscular junction
A synapse between a motor neuron axon and a muscle fiber
Release of chemicals causes the muscle or contract
Each muscle fiber has only one master
Antagonistic muscles
Movement requires the alternating contraction of opposing sets of muscles
Flexor muscle
One that flexed or raises an appendage
Extensor muscle
One that extends an appendage or straightens it
Myasthenia gravis
An autoimmune disease in which the immune system forms antibodies that attack the acetylcholine receptors neuromuscular junctions
Causes the progressive weakness and rapid fatigue of the skeletal muscles
Fast twitch fibers
Produce fast contractions but fatigue rapidly
Anaerobic and do not require oxygen
Slow twitch fibers
Produce less vigorous contractions without fatigue
Aerobic and require oxygen during movement
Proprioceptors
Receptors that detect the position or movement of a part of the body
Muscle spindles
Proprioceptors parallel to the muscle that responds to a stretch
Causes a contraction of the muscle
Stretch reflex
Occurs when muscle proprioceptors detect the stretch and tension of a muscle and send messages to the spinal cord to contract it
Golgi tendon organ
Type of proprioceptor that responds to increases in muscle tension
Acts as a brake against excessively vigorous contraction by sending an impulse to the spinal cord where motor neurons are inhibited
Reflexes
Involuntary, consistent and automatic responses to stimuli
Grasp reflex
Grasps objects places in the hand
Babinski reflex
Extends big toe and fans others when the sole of the foot is stroked
Rooting reflex
Turns head and sucks when cheek is stimulated
Ballistic movements
Movement that once initiated can not be altered or corrected
Ex: yawning, dilation of pupil
Centros pattern generators
Neural mechanisms in the spinal cord or elsewhere that generate rhythmic patterns of motor output
Ex: wing flapping in bird
Promotor cortex
Integrates information about position and posture of the body and organizes the direction of the movement in space
Supplementary motor cortex
Important for organizing a rapid sequence of movements in a particular order
Active seconds before the movement occurs
Readiness potential
A particular type of activity in the motor cortex that occurs before any type of voluntary movement
500 ms before the movement itself
Basal ganglia
A group of large subcortical structures in the forebrain responsible for initiating an action not guided by a stimulus
Lateral corticospinal tract
Controls movement in peripheral areas (hands and feet)
Medial corticospinal tract
Allow control of muscles of the neck, shoulders and trunk
Enable movement like walking, turning, bending, standing up
Caudate nucleus and putamen
Receive input from the cerebral cortex and send output to the globus pallidus
Globus pallidus
Connects to the thalamus which relays information to the motor areas and the prefrontal cortex
Inhibits the thalamus
Parkinson’s diseases
A movement disorder characterized by muscle tremors, rigidity, slow movemos and difficulty initiating physical and mental activity
Caused by death of neurons
Huntington’s disease
Neurological disorder characterized by various motors symptoms
Caused by gradual and extensive brain damage
