Psy300h1f l15; oct. 17, 2011: need efferents to stop out hair cells from amplifying, otherwise getting ringing in ears. Signal sent by afferents to dorsal horn in spinal cord or sensory nuc in brainstem (involving cranial nerves) Then directed to motor nuc to specifc muscles to get motor response in periphery of body. Stretch reflex: stimulus: passive stretch of a muscle by applied load or contraction of antagonist muscle, most important reflex, often unaware of; ex. Stretch reflex function: essential for stabilizing posture; reflex strongest in postural muscles; constantly detecting stretches and making adjustments to keep posture upright; ex. If doze off makes you stand up: latencies (delays) of about 25 ms for forearm muscles, Triceps stretched slight upward movement stretch on opposite side, activate muscle spindles, volley in 1a afferents stretch reflex causes small contraction in stretched muscle. 1b afferents in overcontracted muscle cause inhibition so loosen up to stabilize position.