KIN 330 A - Exam #2

Reflexes

Stereotyped and repeatable actions in the periphery that are caused by stimulation of sensory receptors in the PNS that transmit the signal to the CNS, which then routes the signal back out to the periphery to cause the action.

Interoceptors

Within the viscera and blood vessels

Exteroceptors

Close to the outer surface of the body

Proprioceptors

Within the musculoskeletal system

Two components of body awareness

Viscero-awareness and somatosensory awareness; both have implications for exercise and motor performance.

Receptor sensitivity

The ability of a receptor to detect or discriminate a stimulus

Receptor acuity

Refers to groups of receptors working together

Receptive field

Enable a finer discrimination of stimuli than fewer receptors with larger receptor fields

Muscle spindles

Relatively large receptors located throughout a muscle, though generally concentrated in the muscle belly

Myotatic reflex

Muscle feedback to the CNS and initiate a stretch

Intrafusal fibers

Tiny fibers that the muscle spindle contains, which the CNS can control

Gamma Motor Neurons

Small motor neurons

Gamma Bias

Setting the reflex gain or setting muscle sensitivity

Reciprocal Inhibition

A process that refers to where the synergist muscles are facilitated and antagonist muscles are inhibited

Activation History

Prior amount and type of muscle activity and muscle length are just a few factors that influence the mechanical neural properties of the spindle and how it responds to stretch and contraction

Golgi Tendon Reflex

Refers to as an inverse stretch reflex, does not result in a contraction of the effector organ, and is said to limit contraction force in order to protect the muscle and joints

Joint kinesthetic receptors

Four to five different types of receptors found within joint tissues and in the skin surrounding most joints

Pacinian corpuscles

Receptor types found beneath the skin and in ligaments and tendon sheaths

Ruffini endings

Located in the deep skin and in the collagenous fibers of the joint capsule

Free dendritic endings

Receptors that respond to touch and pain and can act as proprioceptors

Arthrogenic muscle inhibition

Feature referred to as the combined actions of the joint capsule and internal joint kinesthetic receptors often have a strong inhibitory effect on the surrounding musculature

Labyrinthine receptors

Vestibular receptors that Detect the movement of fluid contained in the labyrinth of the inner ear

Vestibulocollic

Refers to rightening reflexes initiated by the vestibular receptors and acting in neck muscles to maintain head position in response to head movements

Cervicocollic reflex

A rightening reflex initiated by neck movements and that act upon neck muscles to keep the head in an upright position and stable position

Cervicospinal reflex

A rightening reflex initiated by neck movements that act upon arm and leg muscles with the purpose to prevent falling, keep the head upright or prepare for landing

Sensory integration

The process of filtering and encoding and encoding multiple sources of sensory information in order to better interpret and understand events

Postural control

The maintenance of body alignment and spatial orientation in order to put the body in a position to enable effective movement and is considered a physiological ability

Muscle tone

Refers to the force with which the muscle resists lengthening, that is its stiffness.

Degrees of freedom

Refers to the large number of possible movement solutions for any given movement task; highlights the need for the nervous system to have mechanisms to determine which solution to use.

Closed-loop

Model of motor control systems in which motor commands rely heavily on ongoing sensory feedback to initiate and modify the commands

Open-loop

Model of motor control systems in which motor commands do not rely on on going feedback; see centrally preprogrammed commands

Generalized Motor Program (GMP)

Defines the basic “form” of the action “the fundamental pattern” or invariants in the movement

Can be used for a class of movements

Schema

When the individual makes a movement that attempts to satisfy some goal, stores four states

-the initial conditions

-the response specifications for the motor program

-the sensory consequences of the response produced

-the outcome of that movement