exam 2 Flashcards
(25 cards)
types of muscle
- skeletal
- cardiac
- smooth
skeletal muscle
- controlled by somatic efferent neurons
- voluntary
- multinucleate
- striated
smooth muscle
- controlled by autonomic efferent neurons
- involuntary
- uninucleate
- no striations
cardiac muscle
- controlled by autonomic efferent neurons
- involuntary
- uninucleate
- striated
muscle cell
muscle fiber
cell membrane of muscle
sarcolemma
cytoplasm of muscle
satcoplasm
endoplasmic reticulum of muscle
sarcoplasmic reticulum
what are skeletal muscles composed of
connective tissue
muscle fasicles
blood vessels
nerves
what are muscle fascicles composed of
muscle fibers (cells)
called syncitum
what are muscle fibers composed of
sarcolemma
t-tubules
sarcoplasm
multinuclei
sarcoplasmic reticulum
sarcoplasmic reticulum
stores calcium
t tubules
extensions of sarcolemma that go into myofibril
triad
t-tubule into interior muscle fiber
actin
- thin filament
- made up of g-actin, tropomyosin, troponin
myosin
- thick filament
- tail and 2 heads
- hinge region allows pivot
A band
anywhere there is myosin (can also have actin overlapping)
I band
only actin present
H zone
only myosin present
M line
where myosin is anchored
Z disk
where actin is anchored
titin
huge protein spring that gives passive tension to muscle
length of sarcomere
about 3 um
sarcomere length during contraction
- z lines get pulled towards each other
- sarcomere shortens BUT length of actin and myosin filaments do NOT change! there is just more overlap of actin and myosin
