Reflex Flashcards
(13 cards)
What is a reflex arc?
A neural pathway involving receptor, sensory neuron, integration center, motor neuron, and effector
What is the stretch reflex and its function?
Muscle stretch stimulates muscle spindle → spinal cord → motor neuron activates muscle to contract
What does a brisk or absent reflex indicate?
Brisk = UMN lesion; Absent = LMN lesion or peripheral nerve issue
What is the brain’s role in modulating reflexes?
Descending pathways from brain inhibit or enhance reflexes subconsciously
Describe the flexor withdrawal and crossed extensor reflexes.
Protective reflexes causing limb withdrawal from pain and extension of contralateral limb for balance
What is the function of Golgi tendon organs?
They monitor muscle tension and prevent overstretch.
What is clonus and what does it indicate?
Rhythmic muscle contractions indicating UMN lesion.
What reflex is tested with the Achilles tendon?
The ankle jerk reflex (S1).
Why are reflexes exaggerated in UMN lesions?
Loss of inhibitory control from the brain.
What is reciprocal inhibition in a reflex arc?
Inhibition of antagonist muscle during reflex.
How is the plantar reflex tested?
By stroking the lateral sole of the foot.
Why is the flexor withdrawal reflex protective?
It withdraws the body part from a painful stimulus.
Which spinal level is assessed with the patellar reflex?
L3–L4.
