The Muscular System: Key Terms Flashcards
actin
one of the two contractile proteins in muscle cells; the other is myosin
agonist
the muscle that carries out a given movement; prime mover
antagonist
the muscle that opposes an agonist; it must relax when the agonist contracts
cardiac muscle
involuntary muscle that makes up the heart wall
fascia
the fibrous sheath of connective tissue that covers a muscle; called deep fascia to differentiate it from the superficial fascia that underlies the skin
fascicle
a small bundle, as of muscle or nerve fibers
insertion
in a given movement, the point where a muscle attaches to a moving part of the skeleton
muscle
and organ that produces movement by contracting; also the tissue that composes such organs
myosin
one of the two contractile proteins in muscle cells; the other is actin
neuromuscular junction (NMJ)
the point of contact, or synapse, between a branch of a motor neuron and a muscle cell
origin
in a given movement, the point where a muscle is attached to a stable part of the skeleton
skeletal muscle
voluntary muscle that moves the skeleton and maintains posture
smooth muscle
involuntary muscle that makes of the wall of hollow organs, vessels, and ducts; visceral muscle
synergist
a muscle that assists an agonist to produce a given movement
tendon
a fibrous band of connective tissue that attaches a muscle to a bone
tonus
a state of steady, partial muscle contraction that maintains firmness; muscle tone
acetylcholine (ACh)
a neurotransmitter that stimulates contraction of skeletal muscles
ALS
amyotrophic lateral sclerosis: a disease caused by motor neuron degeneration resulting in muscular weakness and atrophy; Lou Gehrig disease
chronic fatigue syndrome (CFS)
a disease of unknown cause that involves persistent fatigue, along with muscle and joint pain and other sx; may be virally induced
dermatomyositis
a disease of unknown origin involving muscular inflammation as well as dermatitis and skin rashes
fibromyalgia syndrome (FMS)
a disorder associated with widespread muscular aches and stiffness and having no known cause
muscular dystrophy
a group of hereditary muscular disorders marked by progressive weakness and muscular atrophy
myasthenia gravis (MG)
a disease characterized by progressive muscular weakness; an autoimmune disease affecting the neuromuscular junction
polymyositis
a disease of unknown cause involving muscular inflammation and weakness
repetitive strain injury (RSI)
tissue damage caused by repeated motion, usually overuse of the arm or hand in occupational activities such as writing, typing, painting, or using hand tools; aka repetitive motion injury, cumulative trauma injury, overuse syndrome
sprain
injury to a ligament caused by abnormal or excessive force at a joint, but without bone dislocation or fracture
strain
trauma to a muscle because of overuse or excessive stretch; if severe, may involve muscular tearing, bleeding, separation of a muscle from its tendon, or tendon separation from a bone
tendinitis
inflammation of a tendon, usually caused by injury or overuse; the shoulder, elbow, and hip are common sites; tendonitis
tenosynovitis
inflammation of a tendon and its sheath
CK
creatine kinase: an enzyme found in muscle tissue; the serum CK level increases in cases of muscle damage; creatine phosphokinase
EMG
electromyography: study of electrical activity of muscles during contraction
