Poly Synaptic Flashcards
(31 cards)
What is the Inverse Stretch Reflex?
The Inverse Stretch Reflex, also known as the Golgi Tendon Reflex, is a protective reflex that prevents muscle damage by causing relaxation of the same muscle when there is marked tension.
What is the stimulus for the Inverse Stretch Reflex?
The stimulus is a marked increase in tension or stretch within the muscle.
What are the receptors involved in the Inverse Stretch Reflex?
The receptors are Golgi tendon organs located at the junction of the muscle and tendon.
What is the afferent pathway for the Inverse Stretch Reflex?
The afferent pathway involves myelinated Ib nerve fibers that carry the signal to the spinal cord.
What is the center for the Inverse Stretch Reflex?
The reflex is processed in the spinal cord and is bisynaptic, involving a single inhibitory interneuron.
What is the efferent pathway for the Inverse Stretch Reflex?
The efferent pathway involves α-motor neurons that inhibit (hyperpolarize) the same muscle.
What is the response in the Inverse Stretch Reflex?
The response is the relaxation of the same muscle, preventing excessive tension.
What is the purpose of the Inverse Stretch Reflex?
It prevents muscle tearing by reducing excessive tension and provides feedback to the brain for motor control.
What is the Flexor Withdrawal Reflex?
The Flexor Withdrawal Reflex is a polysynaptic spinal reflex that withdraws a limb in response to a painful stimulus.
What is the stimulus for the Flexor Withdrawal Reflex?
The stimulus is an injurious or painful stimulus.
What are the receptors involved in the Flexor Withdrawal Reflex?
The receptors are free nerve endings that detect pain.
What is the afferent pathway for the Flexor Withdrawal Reflex?
The afferent pathway involves Aδ nerve fibers that carry the signal to the spinal cord.
What is the center for the Flexor Withdrawal Reflex?
The reflex is processed in the spinal cord and involves multiple synapses (polysynaptic).
What is the efferent pathway for the Flexor Withdrawal Reflex?
The efferent pathway involves α-motor neurons that cause contraction of the flexor muscles.
What is the response in the Flexor Withdrawal Reflex?
The response is the flexion and withdrawal of the limb away from the injurious stimulus.
What are the properties of the Flexor Withdrawal Reflex?
- Reciprocal inhibition: contraction of flexors and relaxation of extensors. 2. Crossed extensor reflex: extension of the opposite limb to support body weight if the stimulus is severe enough.
What is the Plantar Reflex?
The Plantar Reflex is a polysynaptic spinal nociceptive reflex modified by the corticospinal tract.
How is the Plantar Reflex tested?
Stroke the lateral part of the sole of the foot with a sharp object from the heel towards the little toe, then medially along the bases of the toes.
What is the normal response in the Plantar Reflex?
The normal response is plantar flexion of the big toe and flexion and adduction of the other toes (flexor plantar reflex).
What is the abnormal response in the Plantar Reflex?
The abnormal response is dorsiflexion of the big toe and extension and abduction (fanning) of the other toes, known as Babinski reflex.
What does the Babinski Reflex indicate?
The Babinski Reflex indicates dysfunction of the corticospinal tract and can occur in conditions such as cerebral hemorrhage, brain or spinal cord tumors, coma, general anesthesia, deep sleep, or in children up to one year old.
What is the Positive Supporting Reaction?
The Positive Supporting Reaction is a reflex that converts a limb into a rigid column to support body weight in response to deep pressure on the sole of the foot.
What is the stimulus for the Positive Supporting Reaction?
The stimulus is deep pressure on the sole of the foot.
What is the response in the Positive Supporting Reaction?
The response is the contraction of flexors and extensors to form a rigid column.
