Ch. 9 A&P
myosin
protein found in thick filaments
actin
protein found in thin filaments
tropomyosin and troponin
regulatory proteins associated with thin filaments in muscle cells
A-band
represents length in sarcomere structure
muscle shortening
what characterizes isotonic concentration contractions in muscle activity
a sustained but wavering contraction
what characterizes unfused tetanus in muscle contraction
muscle lengthening
what defines eccentric contractions in muscle movement
a sustained and smooth maximum contraction
what describes fused tetanus
smooth rely on calmodulin for contraction
what is a distinctive feature in smooth muscles compared to skeletal
no change in muscle length
what is a primary characteristic in isometric contractions
increased force of contraction caused by multiple stimuli
what is temporal summation
stores and releases calcium ions
what is the primary function of the SR in muscle cells
promotes muscle contraction
what is the primary role of acetycholine at the neuromuscular junction
sodium ions enter leading to contraction
what occurs in the muscle cell during depolarization
depolarization surpassing threshold
what triggers muscle contraciton
unfused tetanus
what type of tetanus involves sustained but wavering contraction
isotonic concentric contraction
when lifting a weight, what type of contraction occurs
isometric contraction
which type of contraction generates tension but does not change the muscles length
H-zone
area in center of A-band where there are only THICK filaments
I-band
area only containing THIN filaments
fascicles
bundle of muscle fibers within a muscle
sarcolemma
cell membrane of muscle cell
epimysium
connective tissue surrounding the ENTIRE muscle
center of sarcomere
function of M-line
boundary of the sarcomere
function of Z-line
connective tissue surrounding muscles/structures
function of the fascia
anaerobic processes yield less ATP
how are anaerobic processes different from aerobic processes in terms of ATP generation
calcium binds to troponin exposing actin binding sites
how are muscle contraction initiated
oxidative fibers are aerobic with a greater endurance
how do oxidative fibers differ from glycolic fibers
CP donates a phosphate group to ADP to regenerate ATP
how does creatine phosphate (CP) contribute to ATP regeneration during short bursts of intense exercise
allows sodium to enter the cell
how does the binding of ACh to muscle cell recptors affect ion flow
potassium moves out of cell
how is relaxation achieved
refractory period
in which phase does the muscle become unresponsive to further stimulation
perimysium
Connective tissue surrounding bundles of muscle fibers called fascicles.
endomysium
Connective tissue surrounding individual muscle fibers.
