lab quiz 2, ch7 - reflex arcs

latent period

time between stimulus and contraction

time it takes for all steps of reflex arc to occur

reflex arc

sensory receptor, sensory neuron, motor neuron, and effector that are involved in a quick response to a stimulus

monosynaptic/polysynaptic

effector (reflex arc)

muscle fiber or gland that responds to the motor neuron

monosynaptic reflex

one sensory, one motor neuron

one synapse in s.cord, between sensory/motor neurons

faster than polysynaptic

ex: knee,ankle,tri/biceps jerk

stretch reflex

resists stretching, prevents muscle tearing

helps balance/maintain a constant position

ex: knee,ankle,tri/biceps jerk

monosypnatic

muscle spindle

Stretch receptor

contain intrafusal fibers

stretches w muscle

Sends info through spinal cord, helps w reflexes

visceral reflex

ANS, have smooth muscle + glands as effectors

(simple stretch) Reflex testing

used to locate damage to any component of a reflex arc

finds abnormal reflex responses

Plantar reflex

tests the Babinski response

Babinski response

detects damage to the pyramidal tracts that descend from the brain without synapse

cant determine the level of spinal cord damage

flexion of hallux = good, extension = bad

Simple stretch reflex steps

stumulus activates muscle spindle(receptor)

receptor sensory neuron fires nerve impulse to IC

IC = 1 synapse between sensory/motor neuron

Motor neuron fires impulse and contracts muscle

Jendrassik maneuver

distracting activity while the reflex is being assessed

(clench their teeth, hook their fingers together)

strengthens reflexes

Withdrawl reflex

automatic response to painful or harmful stimuli

helps to quickly protect the body from injury without the person thinking about it first.

Pupillary light reflex

pupil constricts due to light stimulus

both eyes communicate respond through shared neural pathways.

Auditory vs vsiual stimuli

auditory stimuli have faster reactions

Flexion reflex

multiple synapses between sensory/motor neuron

crossed extensor/double reciprocal innervation (withdrawal)

Polysynaptic

parasympathetic neves

pupil constriction, mediate accommodation to a near object

rest/digest,

light is shone into an eye and the iris of that eye constricts

Direct response

light is shone into an eye and the iris of the opposite eye constricts

Consensual response

Upper motor neuron lesion

babinski sign, exaggerated reflexes

Lower motor neuron lesion

diminished/absent reflexes

In the knee-jerk reflex arc, where does the synapse between a sensory neuron and a motor neuron occur?

Within spinal cord

Which of these choices provides a logical description of the stages in a reflex arc?

Sensory neuron, spinal cord, (interneuron), motor neuron, muscle.

What factor could decrease an individual's reaction time during voluntary motion

Practice