1. List the events, in sequence, that occur between the striking of the patellar tendon
and the extension of the leg.
When the patellar tendon is shrieked it stretches the quadriceps tendon which
stimulates the stretch sensory receptors that trigger afferent impulse in a sensory
nerve fiber leading to the spinal cord. The sensory neuron synapses directly with
a motor neuron that conducts efferent impulse to the quadriceps femoris muscle,
triggering contraction. The contraction, coordinated with relaxation of the
antagonistic flexor hamstring muscle causes leg to kick.
2. If a normal stimulus does not bring about the expected response in a stretch
reflex, damage to a specific motor nerve or region of the spinal cord may be
suspected. On the other hand, an abnormal Babinski response may indicate
damage to the spinal cord at any level. Why?
The Babinski response has to do with the nerve paths connected to the spinal cord and
corticospinal tract such that it runs along both sides of the spinal cord. Therefore, an
3. Sensory signals from all regions of the body are sent to the somatosensory
cortex, where they are perceived. Which parts of the body have the largest areas
of the cortex? Which