Med Term Ch 7 Muscular System

Antagonistic

In opposition to each other.

Bradykinesia

Condition of slow movement.

Cardiac muscle

Involuntary and found only in the heart. Highly coordinated contractions pump blood into the vessels of the circulatory system.

Dyskinesia

Abnormal involuntary movements of the extremities, trunk, or jaw.

Electromyogram

Record of the electricity of the muscle.

Electromyography (EMG)

Recording of muscle electrical activity in response to a nerve's stimulation of the muscle.

Fibromyalgia

A common nonarticular rheumatic syndrome characterized by muscle pain.

Hemiplegia

Paralysis on one side of the body.

Hemostasis

The process by which the body seals a ruptured blood vessel to prevent further blood loss.

Hyperkinesia

Excessive movement of muscles of the body as a whole.

Hypertrophy

The enlargement of muscles.

Magnetic Resonance Imaging (MRI)

A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body.

Muscular dystrophy

A general term for the group of inherited myopathies that are characterized by wasting and weakness of the skeletal muscle.

Myalgia

Pain in a muscle or group of muscles.

Myasthenia Gravis

A disease in which antibodies made by a person's immune system prevent certain nerve-muscle interactions, causing weakness in the arms and legs, vision problems, and drooping eyelids or head.

Myeloma

Cancer that arises in plasma cells.

Paraplegia

Paralysis that affects both legs and lower part of the body.

Paresis

Partial paralysis wherein there is still some control of the muscles.

Polymyositis

An inflammatory disease of the muscles closest to the center of the body.

Quadriplegia

Paralysis of all four limbs.

Rhabdomyolysis

Necrosis or disintegration of skeletal muscle.

Skeletal muscle

The muscles responsible for voluntary muscle movement; also called striated muscle.

Smooth muscle

The muscles responsible for involuntary muscle movement; also called visceral muscle.

Sprain

The stretching or tearing of the supporting ligaments.

Strain

An overstretching or overexertion of a muscle or tendon.

Tendinitis

Inflammation of the tendon.

Muscular system

More than 600 muscles that produce movement, maintain posture/stability, move substances, protect organs, and generate heat.

Three muscle tissue types

Skeletal, smooth, and cardiac muscle.

Muscle fiber

Specialized elongated muscle cell capable of contraction.

Excitability

Ability of a muscle-cell membrane to change electrical state and conduct an action potential.

Fascia

Fibrous connective tissue enclosing and organizing muscles.

Skeletal muscle characteristics

Striated, usually voluntary, attached to skeleton; produces movement and stabilizes posture/joints.

Smooth muscle characteristics

Nonstriated, involuntary muscle in walls of hollow organs and passageways, eyes, and skin.

Cardiac muscle characteristics

Striated, involuntary, branched myocardium found only in heart; cells connect via intercalated discs.

Intercalated disc

Specialized junction joining cardiac muscle cells electrically and mechanically for coordinated wave-like contraction.

Sarcomere

Repeating contractile unit producing striations in skeletal and cardiac muscle.

Skeletal-muscle functions

Moves/stops movement; maintains posture and joint stability; controls tract openings; protects organs; produces heat.

Smooth-muscle locations

Walls of bladder, uterus, stomach, intestines, arteries/veins, respiratory/urinary/reproductive tracts; also iris, lens apparatus, and skin.

Cardiac-muscle function

Coordinated contractions pump blood into circulation and generate heartbeat.

Muscle contraction

Shortening/development of tension in muscle fibers that pulls on structures.

Muscle relaxation

Reduction of tension and return/lengthening after contraction.

Antagonistic muscle pair

Muscles with opposing actions; as agonist contracts, antagonist relaxes or controls motion.

Agonist (prime mover)

Muscle chiefly responsible for producing a particular movement.

Postural muscle activity

Small continuous skeletal-muscle adjustments keep body upright and balanced against gravity.

Shivering thermogenesis

Rapid involuntary skeletal-muscle contractions generating heat in cold conditions.

Muscle naming by number of heads

Biceps has two origins/heads; triceps three; quadriceps four.

Muscle naming by size

Maximus indicates largest; minimus indicates smallest.

Muscle naming by shape

Deltoid indicates triangular shape; trapezius indicates trapezoid shape.

Muscle naming by action

Flexor produces flexion; extensor extension; abductor moves away; adductor moves toward midline.

Abductor digiti minimi

Muscle that moves the little finger or toe away from the midline.

Adductor digiti minimi

Muscle that moves the little finger or toe toward the midline.

Duchenne muscular dystrophy (DMD)

X-linked dystrophin deficiency causing progressive muscle weakness, usually beginning in boys before age six; later affects ambulation and breathing.

Cerebral palsy

Nonprogressive disorder from abnormal/interrupted brain development causing variable motor weakness, tone, balance, and coordination problems.

Carpal tunnel syndrome

Median-nerve compression at wrist causing hand pain, numbness, tingling, or weakness.

Paralysis

Loss of muscle strength and voluntary control; may be localized or generalized.

Paresis vs. paralysis

Paresis is partial weakness with some control; paralysis is complete or profound loss of control.

Sprain vs. strain

Sprain injures a ligament at a joint; strain injures a muscle or tendon.

Sprain findings

Pain, swelling, bruising, and impaired joint use after ligament stretch/tear.

Strain findings

Pain, spasm, swelling, cramping, and impaired movement after muscle/tendon overstretch or tear.

Massage therapist

Practitioner who manipulates muscles and soft tissues to relieve pain, support healing, and reduce stress.

Electromyography purpose

Records muscle electrical activity at rest and with activation, often using a needle electrode; helps assess neuromuscular disease.

Electromyogram vs. electromyography

Electromyogram is the resulting record; electromyography is the recording procedure.

MRI

Uses magnetic field and radio waves for detailed internal images, including muscle, ligament, tumor, brain, and spinal-cord evaluation.

Range-of-motion testing

Measures movement available around a specific joint.

Rhabdomyolysis clinical significance

Skeletal-muscle breakdown releases intracellular contents such as myoglobin, which can cause acute kidney injury and electrolyte disturbances.

Homeostasis

Maintenance of relatively stable internal conditions.

Nomenclature

System of names and naming rules used in a field.