Myology Flashcards
what are skeletal muscles comprised of?
faciscles
each fascicle is made up of?
muscle cells
another term for “muscle cells”?
myofiber
T/F each skeletal muscle is an organ?
T
name the types of attachments made by dense regular CT
tendon, aponeurosis
cable-like attachments
tendon
sheet-like attachments
aponeurosis
an entire muscle comprised of fascicles is surrounded by the
epimysium
each (group of muscle fibers) fascicles is surrounded by the
perimysium
each muscle fibers is wrapped by the
endomysium
each myofiber (cell) is composed of
myofibrils
each myofibril is composed of
thin and thick myofilaments
thick myofilaments are composed of the protein
myosin
“the primary protein”; thin myofilaments are composed of
actin
muscle cell membrane
sarcolemma
the cytoplasm of a muscle cell
sarcoplasm
muscle cell membrane
sarcoplasmic reticulum
the function of the sarcoplasmic reticulum
stores calcium ions, release in muscle contraction
function of T-tubules
rapidly conduct a nerve impulse to the interior of muscle cell
definition of sarcomere
the functional contractile unit
Z-disc is in the center, thin myofilament only
I-band
thin and thick myofilaments, dark and light region
A-band
central region in the middle of A-band, only thick myofilament
H-zone
middle of H-zone, thick myofilaments attach to each other
M-line
1 in contraction
muscle stimulated by a nerve
2 in contraction
thick/thin myofilament slide over each other
3 in contraction
sarcomere shortens, triggers contraction
how is a nerve impulse carried from the brain to spinal cord to muscle ?
axon of a motor neuron
where does the axon meet the muscle fiber
neuromuscular junction
what neurotransmitter does the axon release, in order to bind to the sarcolemma?
acetylcholine
location of nerve impulse generated
in the sarcolemma
what causes the sarcoplasmic reticulum to release calcium ions?
nerve impulse initiated by t-tubules
why do calcium ions bind to thin myofilaments?
helps thick myofilament to attach to thin myofilament
what happens as myofilaments slide over one another?
sarcomere shortens, contracting muscle
what happens when nerve impulse stops?
calcium ions return to s.reticulum and myofilaments in resting state
