 Automatic
motor response to stimuli
 Produces the same response every time
 Reflex Arc
 Step One: Arrival of stimulus and activation
of receptor
 Step
2: Activate the sensory neuron
 Step 3: Information processing by
interneuron
 Step 4: Activate motor neuron
 Step 5: Response by effector (muscle or
gland)
 Stretch
Reflex
 Automatic regulation of skeletal muscle
 Allows for posture and balance
 Doctors use to test condition of spinal cord
 Ex: Knee Jerk Reflex
 Withdrawal
Reflex
 Move body away from stimulus
 Strong when stimulus is pain
 Ex: Flexor Reflex
 Involves a limb
 Ex: Grabbing a hot pan
 Babinski
Sign
 Stroke side of sole of foot—results in curled
toes
 Used to test CNS
 Sensation—information
gathered by a
receptor
 Can filter out
 Ex: Feel our clothes?
 Posterior column pathway
 Sends fine touch, pressure, vibration and
position sensations
 Sends to primary sensory cortex in cerebrum