Quiz 3 Study

Proprioceptors

internal receptors located in the skin, joints, muscles and tendons that provide feedback relative to the tension, length and contraction state of muscle, the position of the body and limbs, and movements of the joints

Cerebellum

is a major integrator of sensory impulses and provides feedback relative to motion. It controls the timing and intensity of muscle activity to assist in the refinement of movements

Fascia

is a sheet or band of fibrous connective tissue that envelopes, separates, or binds together parts of the body such as muscles, organs and other soft-tissue structures of the body

Aponeurosis

is a tendinous expansion of dense fibrous connective tissue that is sheet- or ribbonlike in appearance and resembles a flattened tendon. Aponeuroses serve as a fascia to bind muscles together or as a means of connecting muscle to bone, such as the palmar aponeurosis for the palmaris longus

Extensibility

is the ability of muscle to be passively stretched beyond its normal resting length. As an example, the triceps brachii displays extensibility when it is stretched beyond its normal resting length by the biceps brachii and other elbow flexors contracting to achieve full elbow flexion

Contractility

is the ability of muscle to contract and develop tension or internal force against resistance when stimulated. The ability of muscle tissue to develop active tension or contract is unique in that other body tissues do not have this property.

Elasticity

is the ability of muscle to return to its original resting length following stretching. To continue with the elbow example, the triceps brachii displays elasticity by returning to its original resting length when the elbow flexors cease contracting and relax

Gaster

is the central, fleshy portion of the muscle. This contractile portion of the muscle generally increases in diameter as the muscle contracts

Irritability

is the muscle property of being sensitive or responsive to chemical, electrical, or mechanical stimuli. When an appropriate stimulus is provided, muscle responds by developing active tension.

Amplitude

is the range of muscle fiber length between maximal and minimal lengthening

Action

is the specific movement of the joint resulting from a concentric contraction of a muscle that crosses the joint. An example is the biceps brachii, which has the action of flexion at the elbow

Proprioception

is the subconscious mechanism by which the body is able to regulate posture and movement by responding to stimuli originating in the proprioceptors embedded in the joints, tendons, muscles and inner ear

Innervation

occurs in the segment of the nervous system responsible for providing a stimulus to muscle fibers within a specific muscle or portion of a muscle. A particular muscle may be innervated by more than one nerve, and a particular nerve may innervate more than one muscle or portion of a muscle.

Isometric

occurs when active tension is developed within the muscle but the joint angles remain constant (Static)

Dendrites

one or more branching projections, which transmit impulses to the neuron and cell body

Stabilizers

surround the joint or body part and contract to fixate or stabilize the area to enable another limb or body segment to exert force and move

Kinesthesis

the conscious awareness of the position and movement of the body in space

Motor Neurons

transmit impulses away from the brain and spinal cord to muscle and glandular tissue

Sensory Neurons

transmit impulses to the spinal cord and brain from all parts of the body

Force Couples

two or more forces are pulling in different directions on an object, causing the object to rotate about its axis

Palpation

using the sense of touch to feel or examine a muscle as it contracts

Synergist

Muscles that assist in the action of an agonist but are not necessarily prime movers for the action, known as guiding muscles, assist in refined movement and rule out undesired motion. Synergist muscles may be either helping synergists or true synergists

Insertion

Structurally, the distal attachment, or the part that attaches farthest from the midline or center of the body, is considered the insertion. Functionally and historically, the most movable part is generally considered the insertion

Spinal Cord

common pathway between the CNS and the peripheral nervous system (PNS)

Peripheral Nervous System (PNS)

contains all the remaining nerves throughout the body. It has the most specific control and integrates various simple and complex spinal reflexes, as well as cortical and basal ganglia activity

True Synergist

contract to prevent an undesired joint action of the agonist and have no direct effect on the agonist action

Concentric

contractions involve the muscle developing active tension as it shortens (movement against gravity)

Isotonic

contractions involve the muscle developing active tension to either cause or control joint movement (dynamic)

Eccentric

contractions involve the muscle lengthening under active tension (control movement with gravity)

Basal Ganglia

control the maintenance of postures and equilibrium and learned movements such as driving a car. Sensory integration for balance and rhythmic activities is controlled here

Neutralizers

counteract or neutralize the action of other muscles to prevent undesirable movements such as inappropriate muscle substitutions. They contract to resist specific actions of other muscles

Helping Synergist

have an action in common but also have actions antagonistic to each other. They help another muscle move the joint in the desired manner and simultaneously prevent undesired actions

Cerebral Cortex

highest lvl of control, provides for the creation of voluntary movement as aggregate muscle action but not as specific muscle activity

Brain Stem

integrates all central nervous system activity through excitation and inhibition of desired neuromuscular actions and functions in arousal or maintaining a wakeful state

Dermatome

A defined area of skin supplied by a specific spinal nerve

Origin

From a structural perspective, the proximal attachment of a muscle or the part that attaches closest to the midline or center of the body is usually considered to be the origin

Extrinsic

Pertaining usually to muscles that arise or originate outside of (proximal to) the body part on which they act. The forearm muscles that attach proximally on the distal humerus and insert on the fingers are examples of extrinsic muscles of the hand

Intrinsic

Pertaining usually to muscles within or belonging solely to the body part on which they act. The small intrinsic muscles found entirely within the hand are examples

Neuron Cell Body

Portion of a neuron containing the nucleus but not including the axon and dendrites

Myotatic/Stretch Reflex

When rapid stretch occurs, an impulse is sent to the CNS. The CNS then activates the motor neurons of the muscle and causes it to contract

Myotome

a muscle or group of muscles supplied by a specific spinal nerve

Isokinetics

a specific technique that may use any or all of the different types of contractions

Axon

an elongated projection that transmits impulses away from neuron cell bodies

Interneurons

are central or connecting neurons that conduct impulses from sensory neurons to motor neurons

Tendon

are tough yet flexible bands of fibrous connective tissue, often cordlike in appearance, that connect muscles to bones and other structures. By providing this connection, tendons transmit the force generated by the contracting muscle to the bone

Neuron

basic functional units of the nervous system responsible for generating and transmitting impulses are nerve cells

Afferent Nerves

bring impulses from receptors in the skin, joints, muscles, and other peripheral aspects of the body to the CNS

Efferent Nerves

carry impulses to the outlying regions of the body

Antagonist

muscles have the opposite concentric action from agonists

Agonist

muscles, when contracting concentrically, cause joint motion through a specified plane of motion (prime movers)