MUSCULAR SYSTEM (2) Flashcards
smooth muscle
involuntary muscles found in the walls of hollow internal organs
cardiac muscle
involuntary muscles found only in the heart wall
skeletal muscle
voluntary muscles attached to the skeleton (antagonist- works in pairs)
tendon
connective tissue that connects muscle to the bone
origin
attachment of the muscle on a stationary bone
insertion
attachment of a muscle on a bone that moves
gluteus maxims
)makes up the buttocks and is the largest muscle) extends thigh to form buttocks
deltoid
(shaped like a triangle) abducts and raises arm at shoulder point
rectus abdominis
longitudinal muscle of the abdomen (flexes spine)
masseter
closes jaw
trapezius
extends head; raises and abducts shoulders dorsally
external oblique
compresses abdomen; rotates trunk
pectoralis major
flexes and adducts should and arm ventrally (pulls arm across chest)
latissimus dorsi
extends and adducts shoulder and arm dorsally (pulls arm across back)
triceps branchii
extends forearm
sartorius
rotates thigh (sitting cross-legged)
sarcolemma
plasma membrane
sarcoplasm
the cytoplasm
muscle fiber
a cell containing the usual cell components
skeletal muscle contraction
- nerve impulses travel down motor neurons and stimulate muscle fibers at neuromuscular junctions
- when Ca2+ are released into muscle fibers, actin filaments slide past myosin filaments
- synaptic vesicles release Ach which binds to protein receptors causing Ca to leave the sarcoplasmic reticulum and myofibril contraction follows.
muscle twitch
a single contraction that lasts only a fraction of a second
summation
increased muscle contraction until maximal sustained contraction is reached
tentanus
maximal sustained contraction
tone
a continuous slight tension maintained by muscle fibers that take turns contracting
sprain
twisting of a joint involving muscles, ligaments, tendons, blood vessels, and nerves
strain
an injury that causes over stretching of a muscle near a joint
tendinitis
inflamed tendon like tennis elbow
bursitis
inflamed bursa (cortisone injections)
muscular dystrophy
progressive degeneration and weakening of muscles
myasthenia gravis
autoimmune disease characterized by weakness that affects the muscles of the eyelids, face, neck, and extremities
myalgia
achy muscles due to injury or infection
movement is essential to maintaining
homeostasis
antagonistic
muscles that work in opposite pairs
synergistic
muscles working in groups for a common action
proteins
actin and myosin are
bursae
Saclike, fluid- filled structures, lined with synovial membrane, that occurs near a joint.
actin
One of two major proteins of muscle; makes up thin filaments in myofibrils of muscle fibers.
myosin
One of two major proteins of muscle; makes up thick filaments in myofibrils of muscle fibers.
tropomyosin
Protein that functions with troponin to block muscle contraction until calcium ions are present.
ATP (adenosine triphosphate)
Nucleotide with three phosphate groups. The breakdown of ATP into ADP + P makes energy avail-able for energy- requiring processes in cells.
ligaments
Tough cord or band of dense fibrous connective tissue that joins bone to bone at a joint.
