LPN A&P chapter 9 Muscular System

isotonic contraction

A muscle contraction that pulls on the bones and produces movement of body parts.

pectoralis major

Adducts and flexes humerus, chest

Myoglobin

An oxygen-storing, pigmented protein in muscle cells.

Flexion

Bending at a joint or decreasing the angle between two bones

Tendon

Connects muscle to bone

Sarcomere

Contractile unit of muscle

Diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathing

Abduction

Movement away from the midline of the body

Adduction

Movement toward the midline of the body

isometric contraction

Muscle contracts but there is no movement, muscle stays the same length

cardiac muscle

Muscle of the heart

intercostal muscles

Muscles which move the rib cage during breathing

Supination

Palm up

Zygomaticus

Smiling muscle, raises corners of mouth

extension

Straightening a joint or increasing the angle between two bones

Insertion

The attachment of a muscle tendon to a moveable bone or the end opposite the origin

sliding filament model

The theory explaining how muscle contracts, based on change within a sarcomere, the basic unit of muscle organization, stating that thin (actin) filaments slide across thick (myosin) filaments, shortening the sarcomere; the shortening of all sarcomeres in a myofibril shortens the entire myofibril

Myosin

Thick filament of protein found in skeletal muscle cells

Actin

Thin filament of protein found in muscles

Inversion

Turning the sole of the foot inward

Tetanus

a bacterial disease marked by rigidity and spasms of the voluntary muscles.

poliomyelitis

a viral infection of the gray matter of the spinal cord

Deltoid

abducts arm

gluteus medius

abducts thigh

adductor

adducts thighs

myasthenia gravis

autoimmune neuromuscular disorder characterized by weakness of voluntary muscles

Hamstrings

back of thigh

Dorsiflexion

bending of the foot or the toes upward

plantar flexion

bends the foot downward at the ankle

contusion

bruise

fasicles

bundles of muscle fibers

3 types of vertebrae

cervical, thoracic, lumbar

Rotation

circular movement around an axis such as the shoulder joint

orbicularis oculi

closes eye

Masseter

closes jaw

external oblique

compresses abdomen

internal oblique

compresses abdomen

transverse abdominis

compresses abdomen

Injection sites

deltoid, gluteus medius, quadricep

tibialis anterior

dorsiflexes and inverts foot

extensor muscles in forearms

extend wrist and hand

latissimus dorsi

extends and adducts humerus

triceps brachii

extends forearm

Trapezius

extends neck and adducts scapula

gluteus maximus

extends thigh

Flexor muscles in forearm

flex wrist and hand

rectus abdominis

flexes and rotates vertebral column

fibularis

flexes foot

Brachialis

flexes forearm

biceps brachii

flexes forearm at elbow

Sternocleidomastoid

flexes neck; rotates head

quadriceps femoris

front of thigh, extends leg

muscular dystrophy

group of hereditary diseases characterized by degeneration of muscle and weakness

myositis

inflammation of muscle

strain

injury from over exertion, accompanied by myalgia and may result in inflammation

smooth muscle

involuntary muscle found in internal organs digestive tract, blood vessels & ureters

orbicularis oris

kissing muscle, puckers lips

Fibromyositis

muscle and tendon inflammation

Sarcolemma

muscle cell membrane

Myopathies

muscle disorders

origin of a muscle

muscle end attached to the bone that does not move when the muscle contracts

eccentric contraction

muscle lengthens as it maintains tension

Illopsoas

muscle of the upper thigh near the pelvis

concentric contraction

muscle shortens

Synergist

muscle that aids a prime mover in a movement and helps prevent rotation

prime mover

muscle with the major responsibility for a certain movement

Antagonist

opposes the prime mover

cramp

painful localized muscle spasm

Pronation

palm down

Gastrocnemius

plantar flexes foot

function of muscles

produce movement, maintain posture, stabilize joints, generate heat

Frontal Muscle

raises eyebrows

striated muscle

skeletal muscle

skeletal muscle

striated and voluntary 40-50% of bodyweight

Circumduction

the circular movement at the far end of a limb

Mastication

the process of chewing

Eversion

turning the sole of the foot outward