ch10pt1 Flashcards
muscle cell (or fiber)
myocyte
skeletal muscle is comprised of (4)
muscle tissue, connective tissues, nerves, and blood vessels
layers of connective tissues in muscles (3)
epimysium, perimysium, endomysium
outer collagen layer surrounding entire muscle
epimysium
separates muscle from surrounding tissues
epimysium
surrounds muscle fiber bundles (fascicles)
perimysium
brings blood vessel and nerve supply to fascicles
perimysium
surrounds individual muscle cells/fibers
endomysium
contains capillaries and nerve fibers for muscle cells
endomysium
Contains myosatellite cells (stem cells) that repair damage
endomysium
collagen fibers from all three muscle layers come together at ______
end of muscle
connective tissue at end of muscles may attach to
bone matrix
bundle of collagen at the end of a muscle
tendon
sheet of collagen at the end of a muscle
aponeurosis
connection of muscle pulls on
attached bone
skeletal muscles are _____ ______, controlled by nerves of the ___ ___ ___.
voluntary muscles, central nervous system
supply large amounts of oxygen, carries away wastes, supply nutrients (glucose, fatty acids)
skeletal muscle’s extensive vasculature
skeletal muscles develop through fusion of
myoblasts
multinucleate cells have increased production of
proteins and enzymes
myoblasts which don’t fuse to become muscle fibers
become myosatellite cells
aid in muscle repair
myosatellite cells
cell membrane of a muscle fiber
sarcolemma
the sarcolemma surrounds the
sarcoplasm (cytoplasm for muscle cell)
change in ______ ______ triggers muscle contraction
transmembrane potential
narrow tubules reaching deep into myocyte. continuous with sarcolemma.
transverse tubules (T tubules)
T tubules transmit ___ ___ through a cell, allow entire muscle fiber to ____ ____.
action potential, contract simultaneously
lengthwise subdivisions (threads) within a muscle fiber
myofibrils
myofibrils are made up of a bunch of ____. they are responsible for muscle contraction
myofilaments (protein filaments)
types of myofilaments (2)
thin and thick
myofilament type made mostly of the protein actin
thin filaments
myofilament type made of the protein myosin
thick filaments
Myofilaments are organized into repeating pattern along the length of the myofibril causing
striations
Stores high concentrations of calcium. A membranous structure surrounding each myofibril
sarcoplasmic reticulum (SR)
specialized smooth endoplasmic reticulum (SER) found in muscle cells
sarcoplasmic reticulum (SR)
SR forms chambers called ____ ____ attached to T tubules
terminal cisternae
formed by one T tubule and two terminal cisternae
Triad
a repeating pattern of myofilaments. creates a striped or striated pattern within myofibrils
sarcomere
structural unit forming myofibrils. The smallest contractile units of muscle.
sarcomere
(within a sarcomere) thick, dark filaments are ______ and thin, light filaments are ______.
A bands, I bands
where I band meets an I band in a sarcomere
Z line
The center of the A band, and technically the sarcomere. Connects thick filaments to each other
M line
area around the M line. Has thick filaments only. no thin filaments
H band
The densest, darkest area on a light micrograph. Where thick and thin filaments overlap.
Zone of overlap
Where thick and thin filaments interact (contraction occurs)
Zone of overlap
__ line connects thin filament (I band) to thin filament. The __ line connects thick filaments (A band) to thick filament.
Z line, M line
stabilizes/returns a sarcomere to its original shape. Has elastic properties
titin
