Chapter 10: Muscle Tissue Flashcards
Contains epithelia, connective, and nervous tissue; composed of cells that optimize the universal cell property of contractility
Muscle tissue
the three types of muscle tissue
skeletal, cardiac, and smooth
contains bundles of very long, multinucleated cells with cross-striations; quick voluntary control
skeletal muscle
cross-striations and is composed of elongated, often branched cells bound to one another at structures called intercalated discs; rhythmic involuntary contractions
cardiac muscle
consists of collections of fusiform cells, which lack striations and have slow, involuntary contractions
smooth muscle
the cytoplasm of muscle cells
sarcoplasm
the smooth ER of muscle cells
sarcoplasmic reticulum
the muscle cell membrane and its external lamina
sarcolemma
During embryonic muscle development, mesenchymal _____ fuse, forming _____ with many nuclei. Then the further differentiate to form ____ muscle fibers
myoblasts; myotubes; striated
elongated nuclei are found peripherally just under the _______, a nuclear location unique to skeletal muscle fibers/cells
sarcolemma
a small population of reserve progenitor cells
muscle satellite cells
an external sheath of dense irregular connective tissue, surrounds entire muscle; carries large nerves, blood vessels, and lymphatics
epimysium
thin connective tissue layer that immediately surrounds each fascicle
perimysium
bundle of muscle fibers that make up a functional unit
fascicle
very thin layer of reticular fibers and scattered fibroblasts; surrounds the external lamina of individual muscle fibers
endomysium
___________ is an increase in the size of the cells, while _______ is an increase inn the number of cells
hypertrophy; hyperplasia
______ in these connective tissue layers of muscle serve to transmit the mechanical forces generated by the contracting muscle cells/fibers
collagens
______ CT layer becomes the tendon
epimysium
________ junctions which join the muscle to bone, skin, or another muscle
myotendinous
long cylindrical filament bundles; run parallel to the long axis of the fiber
myofibrils
the dark bands on the myofibrils; anisotropic or birefringent in polarized light
A bands
the light bands on the myofibrils; isotropic or doesn’t alter polarized light
I bands
each I band is bisected by a dark transverse line called ____
Z disc
the repetitive functional subunit of the contractile apparatus; extends from Z disc to Z disc
sacromere
each H band is bisected by a dark transverse line called ____
M line
narrow, less dense region of A band
H zone
Th A and I banding pattern in sarcomeres is due mainly to the regular arrangement of thick and thin ________
myofilaments
thick myofilaments are ________ and think myofilaments are _____
myosin; F-actin
large complex with two identical heavy chains and two pairs (4 in total) of light chains
myosin
the myosin heads bind both actins, forming transient crossbridges between the thick and thin filaments, and ATP, catalyzing energy release
actomyosin ATPase activity
thin, helical filaments that run between the thick filaments
actin