Exam 3 Flashcards
muscle tissue types
skeletal
cardiac
smooth
characteristic features of skeletal muscle
striations
multi-nucleated
nuclei pushed to periphery
layers of skeletal muscle
epimysium: covers whole muscle
perimysium: covers muscle fascicle
endomysium: covers muscle fiber
sarcomere
smallest functional unit of muscle
Z disc to Z disc
A band
thick + thin filaments
I band
thin filaments
H zone
thick filaments
transverse tubules
invaginations of sarcolemma that help to spread action potential across muscle fiber
triad
transverse tubule + 2 terminal cisternae of the SR
located in zones of overlap
motor end plate
sarcolemmal surface that contains Ach receptors and junctional folds to increase SA
what type of channel is ACh
sodium
what happens to the components of a sarcomere during contraction
Zones of overlap get larger
H zones and I bands get smaller
Z lines come closer together
A band remains constant
components of troponin complex
TnI, TnC, TnT
which part of the troponin complex binds to Ca++
TnC
what step begins the muscle contraction in skeletal muscle
binding of Ca++ to TnC
types of skeletal muscle fibers
fast and slow twitch fibers
fast twitch fibers
contract quickly, fatigue quickly
anaerobic respiration
ex: extraocular muscles
slow twitch fibers
contract slowly, fatigue slowly
aerobic respiration
ex: postural muscles
muscle growth types (2)
hypertrophy: increase in muscle fiber size
hyperplasia: increase in muscle fibers
muscle atrophy
primary: # of fibers decreases
secondary: size of fibers decreases
