18 terms

Reflex Physiology

An automatic response to a stimulus
Reflex arc
The wiring of a particular reflex
Innate reflex
Reflexive response present at birth
Learned reflex
Reflex acquired through experience
Monosynaptic reflex
Simplest reflex arc in which a sensory neuron synapses directly on a motor neuron that acts as the processing center
Polysynaptic reflex
Reflex that has at least one interneuron placed between the sensory afferent and the motor efferent, thus having a longer delay between stimulus and response
Somatic reflex
Reflex which controls skeletal muscle contractions
Visceral reflex
Controls the activities of smooth and cardiac muscles and glands, including eyes
Cranial reflexes
Reflexes processed in the brain
Spinal reflexes
Simple, automatic behaviors that are processed in the spinal cord.
Ipsilateral reflex
When a stimulus occurs on one side of the body and the reflex action occurs on the same side of the stimulus
Contralateral reflex
When a stimulus occurs on one side of the body and the reflex action occurs on the opposite side of the stimulus
Stretch reflex
Purpose: To prevent injury from over stretching a muscle
Result: Contraction of the muscle that is stretched
Sensed by muscle spindles
Monosynaptic, ipsilateral, spinal, somatic
Tendon reflex
Purpose: to prevent damage from development of too much tension in a muscle
Result: Inhibition of the muscle that is contracting
Sensed by Golgi tendon organ
Polysynaptic, ipsilateral, spinal, somatic
Flexor reflex
Purpose: to protect the body from further injury
Result: flexion of the affected limb
Sensed by nociceptors
Polysynaptic, ipsilateral, spinal, and somatic
Crossed Extensor reflex
Purpose: to stabilize the body position when a painful stimulus results in flexion of an opposite limb (paired with flexor reflex)
Results in extension of the opposite limb
Sensed by nociceptors
Polysynaptic, contralateral, spinal, somatic
Excitatory/Inhibitory neurons
Excitatory - refers to enhancing nervous impulse
Inhibitory - refers to reducing nervous impulse
(Both may act to integrate or moderate signals between neurons.)
Intrafusal Fibers
Intra- Located on the inner part of the muscle, are the sensory fibers
Extra- Part of muscle spindle that make motor fibers that develop tension