Chapter 8- The Control of Movement Flashcards
Name the three categories of vertebrate muscles
Smooth muscles
Skeletal or Striated muscles
Cardiac Muscles
What are Smooth Muscles?
Muscles that control digestive systems and other organs
What are Skeletal or Striated Muscles?
Ones that control movement
What are Cardiac Muscles?
Heart muscles, these have properties of both smooth and skeletal muscles
What is the Main Neurotransmitter in the Movement Systems?
Acetylcholine
What is a Neuromuscular Junction?
A Synapse between a motor neuron and muscle fiber
Muscles are composed of…
mainly individual fibers
Each Muscle receives information from how many axons?
Only on, but an axon may innervate many muscle fibers
What are Antagonistic Muscles?
Muscles that are opposing sets. Movement requires contraction of these.
What are the two types of Antagonistic muscles?
Flexor muscles and Extensor muscles
What do flexor muscles do?
flexes/ raises
What do extensor muscles do?
extends/ straightens
What does acetylcholine always do to skeletal muscles on contact?
Excites them
What is Myasthenia Gravis?
An Autoimmune disease in which there is a deficit in Acetylcholine and impairs movement
What are Fast- Twitch Fibers?
Fibers that produce fast contractions and fatigue quickly.
Ex. Running
What are Slow-Twitch Fibers?
Fibers that produce a less vigorous contraction and do not fatigue.
Ex. Lips
Which fibers are Aerobic?
Slow-Twitch fibers are aerobic and use oxygen .
Fast- Twitch fibers are anaerobic and do not use oxygen at the time, which is why they fatigue
What is a Proprioceptor?
receptor that detects position or movement of a part of the body. Fluidity of movement depends on this
What is a Stretch Reflex?
Occurs when muscle proprioceptors detect the stretch and tension of a muscle and send messages to the spinal cord to contract it
What is a Muscle Spindle?
Receptor parallel to the muscle that responds to a stretch, causing a contraction of the muscle
What are Golgi Tendon Organs?
another type of proprioceptor that responds to increases in muscle tension.
located in the tendons at the opposite ends of the muscle
Besides controlling important reflexes, what else do Proprioceptors do?
provide the brain with information. They act as a brake against excessively vigorous contractions by sending an impulse to the spinal cord where the motor neurons are inhibited
What are Reflexes?
Consistent, involuntary, automatic responses to stimuli
True or False. Few behaviors can be classified as purely voluntary or involuntary, reflexive or nonreflexive?
True.
True or False. In some cases, voluntary behavior requires inhibiting an involuntary response?
True.
What is Ballistic movement?
Movements that once they are initiated, cannot be altered or corrected. Ex. Stretch reflex, dilation of pupil.
True or False. Most behaviors are subject to feedback correction?
True. Ex. Wavering of Pitch
Many behaviors consist of rapid sequences of..
Individual movements
What is a Central Pattern Generator?
Neural mechanisms in spinal cord that generate rhythmic patterns of motor output
What is a Motor Program?
A Fixed Sequence of movements that is either learned or built into the nervous system
Ex. Mouse grooming itself, or yawning
Once begin, the sequence is fixed from beginning to end. It is automatic in the sense that thinking or talking about it interferes with the action
The Grasp reflex is…
When you place an object in an infants palm and it closes its hand around it
The Babinski reflex is…
when you run your finger down the sole of a baby’s foot, it extends it’s big toe and fans others
The Rooting reflex is…
Rooting for food, turns head a sucks when cheek is stimulated
What happens to the infant reflexes as we age?
They fade away but the connections remain intact
Why is understanding how the brain controls movement important?
The possibility of curing paralysis
What did Fritsch and Hitzig find concerning the Primary Motor Cortex?
Direct stimulation of the Primary Motor Cortex elicits movement