Module 7 (Ch. 17) Flashcards
What is a neuron?
Cell specialized to carry electrical signal
What is a nerve impulse?
Electrical signal carried by neurons
What are the 3 components of a neuron?
Dendrites
Cell body
Axon
What carries nerve impulse toward cell body?
Dendrites
What carries nerve impulse away from cell body?
Axon
What are afferent neurons?
Sensory neurons
What is an integrative neuron?
Integrates/processes the sensory stimuli received from sensory neurons
What are efferent neurons?
Motor neurons
[Gray/White] matter is on the outside of the cerebrum.
Gray
[Gray/White] matter is on the inside of the cerebrum.
White
What are isolated clusters of gray matter found within white matter called?
Nuclei or ganglia
Why is white matter white?
Myelin
What does myelin do?
Sheaths axons and helps speed conduction of nerve impulses
Where do connections and processing occur in the brain?
Gray matter of cerebrum (then sent to the white matter to carry signals to distant sites)
The inside of the spinal cord is [gray/white] and the outside is [gray/white]
Inside: gray
Outside: white
Where do connections occur in the spinal cord?
Inner gray matter
What are white matter tracts of the spinal cord composed of?
Ascending pathways - sensory information
Descending pathways - motor information
How many pairs of spinal nerves are there?
31
How many pairs of cranial nerves are there?
12
Can peripheral nerves contain both sensory and motor neurons?
While some are one or the other, some nerves are mixed
Where does voluntary motor control originate?
Cerebral cortex (outer portion of the cerebrum)
What is an upper motor neuron?
Motor neuron that travels down in a descending white matter tract of the spinal cord
What is a reflex arc?
Pathway of a reflex has an arc-like shape
What is the purpose of a reflex?
Automatic responses to protect from danger (specifically children)
How can we modify a reflex?
Descending connections from the brain to the reflex arc via UMN can increase response of a reflex or inhibit it
What is a learned/patterned behavior?
Activity that is learned and so well patterned that it is carried out in what appears to be a “reflexive” manner
After so many repetitions, can perform activity without conscious thought (like driving)
What is neural facilitation?
How all associations are made and why learned behaviors become so rooted in the nervous system
Functionally - responses reinforced through repetition and intensity
Structurally - physical changes to pathways of neurons that lower thresholds
What is the problem with neural facilitation in terms of a tight muscle?
If relationship of muscle tightening is not addressed, pattern of muscle tightening from certain stimuli becomes entrenched; triggering stimulus can tighten muscle more easily next time.
How is neural facilitation used in physical therapy?
Working with the nervous system, helping clients to unlearn pattern of response and relearn a new and healthier pattern of response.
Facilitating good technique is crucial in PT.
What is the Feldenkrais technique?
movement therapy that seeks to create client awareness of their movements including their faulty patterns of movement
What is reciprocal inhibition?
Neurologic reflex that causes antagonist to a joint action to relax when the mover is directed to contract.
Nervous system sends both facilitatory impulses to the LMN that control the mover and inhibitory impulses to the LMN that control the antagonist
How can reciprocal inhibition be used to palpate muscles?
If need to palpate a muscle that contracts with others, perform a function that inhibits the surrounding muscles.
Ex: palpating brachialis - flex forearm while pronated to activate brachialis but inhibit biceps
How can reciprocal inhibition be used to stretch muscles?
Have client contract mover muscle and inhibit the antagonist, which allows a deeper stretch of the antagonist.
What is proprioception?
Ability of the nervous system to know the body’s position in space and the body’s movement through space.
What are mechanoreceptors?
Sensory receptor cells sensitive to mechanical pressure stimuli
What are the 3 categories of proprioceptors
Fascial/joint
Muscle
Inner ear
What are the 2 major types of fascial/joint proprioceptors?
Pacini’s corpuscles
Ruffini’s endings
Muscle proprioceptors create proprioceptive reflexes in order to
protect muscles and tendons from injury
What are the 2 major types of muscle proprioceptors?
Muscle spindles
Golgi tendon organs
Proprioceptive sensation from the inner ear (both static and dynamic) is often referred to as the sense of…
equilibrium
Where are inner ear static proprioceptors for head position located?
In vestibule of inner ear
Where are inner ear dynamic proprioceptors for movement located?
Semicircular canals of inner ear
What other receptors can provide proprioceptive function besides mechanoreceptors?
Vision, pain, touch
Why do you have to close your eyes during a field sobriety test?
Alcohol decreases proprioception, but you can use your eyes to help make up for that loss
How does pain work proprioceptively?
Draws attention to that body part
What are the 2 deep (and major) mechanoreceptors of touch?
Pacini’s corpuscles
Ruffini’s endings
(Also joint proprioceptors)
What are the 4 superficial mechanoreceptors of touch?
Meissner’s corpuscles
Merkel’s discs
Krause’s end bulbs
Free nerve endings
Where are joint proprioceptors?
Within dense fascia, in and around joint capsules, in deep muscular fascia
What are joint proprioceptors?
Mechanoreceptors in and around capsules of joints
When a joint is compressed on one side, it is ______ on the other
stretched
What are interstitial myofascial receptors?
A 3rd group of mechanoreceptors (aside from Pacini’s corpuscles and Ruffini’s endings) found within joint capsules. Believed to be involved in pain reception and proprioception.