somatosensation Ability to sense touch, pain and temperature T/F: sensory information detected from one side of the body is perceived by the opposite side of the brain true alpha motor neuron a motor neuron that innervates extrafusal muscle fibers extrafusal muscle fiber one of the muscle fibers that are responsible for the force exerted by contraction of a skeletal muscle the final common path a term for the spinal cord motoneurons, the ones ultimately responsible for stimulating peripheral muscles to generate behavior cutaneous sensation touch, pressure, heat, cold, and pain free nerve ending respond to temperature changes and pain encapsulated receptor primarily mechanoreceptors that inform about object movement and friction proprioception our sense of body position proprioceptor low threshold mechanoreceptors that inform the CNS about movement and position by detecting the stretch of the tissue in which they lie muscle spindle fusiform structures that run in parallel to extrafusal fibers; conveys information about muscle length and stretch which muscles have more spindles? muscles used for precision movements (extraocular eye muscles, fingers/hands) golgi tendon organ detects tension joint receptors act as limit detectors gamma motor neuron innervates intrafusal muscle fibers; causes contraction of the spindle, keeping it taut what innervates muscle spindles? One efferent fiber and one or more afferent fibers type Ia afferent sensitive to speed and length of stretch; faster type II afferent sensitive to length of stretch, not speed; slower reciprocal inhibition the simultaneous contraction of one muscle and the relaxation of its antagonist to allow movement to take place where are GTOs located? myotendinous junction how do vibration illusions work? type Ia spindle afferents are selectively stimulated visual capture the tendency for vision to dominate the other senses ruffini-like receptors (type I) slowly adapting nerve fibers; signals static joint position, joint movement, direction and speed of movement paciniform receptors (Type II) rapidly adapting nerve fibers; signals joint movement (especially velocity) golgi endings (Type III) slowly adapting receptors; only found in ligaments (role unknown) free nerve endings (Type IV) signals tissue damage; located in fibrous capsule and ligaments which receptors are found in the fibrous part of the joint capsule? ruffini-like and paciniform receptors