Final answer:
The stretch reflex starts with sensory stimulation of a muscle spindle, followed by signals sent through afferent transmission to the spinal cord, processed by interneurons, then sent out via efferent transmission to induce muscle contraction and inhibit antagonist muscles.
Step-by-step explanation:
The main steps in the myotatic (stretch) reflex are: sensory stimulation, afferent transmission, interneuron processing, efferent transmission, and muscle contraction. This sequence begins when a muscle spindle receptor is activated due to the stretching of a skeletal muscle. The activated muscle spindle sends a signal along an afferent (sensory) nerve to the spinal cord. Inside the spinal cord, the signal is processed by interneurons, which relay the signal to a motor nerve through efferent (motor) transmission. The motor nerve then stimulates the stretched muscle to contract, which is the body's way of maintaining muscle length. Concurrently, a collateral branch from the muscle spindle inhibits the motor neurons of the antagonist muscles.