4/3 lab quiz Flashcards
What type of interaction is responsible for muscle cell contraction?
myofilament
What protein are thin filaments primarily composed of?
actin
-F and G
What protein are thick filaments primarily made of?
myosin II
What is the cytoplasm of muscle cells called?
sarcoplasm
what are the three types of striated muscle?
skeletal, visceral striated, and cardiac
what are the two names given to skeletal muscle cells?
muscle fiber
multinucleated syncitium
A muscle fiber is formed during development by the fusion of small, individual muscle cells called _____________________
myoblasts
consists of the plasma membrane of the muscle cell, its external lamina, and the surrounding reticular lamina
sarcolemma
the delicate layer of reticular fibers that immediately surrounds individual muscle fibers
endomysium
the thicker connective tissue layer that surrounds a group of fibers to form a bundle or fascicle
perimysium
functional units of muscle fibers that tend to work together to perform a specific function
fascicles
the sheath of dense connective tissue that surrounds collection of fascicles that constitutes the muscle; also called?
epimysium
deep investing fascia
functions primarily to store oxygen in muscle fibers and provides a ready source of oxygen for muscle metabolism
myoglobin
-small fibers that appear red in fresh specimens and contain many mitochondria and large amounts of myoglobin and cytochrome complexes
-slow-twich
-resistant to fatigue
Type I fibers
-intermediate fibers seen in fresh tissue
-contain large amounts of glycogen and are capable of anaerobic glycolysis
-fast-twitch
Type IIa fibers
-large fibers that appear light pink in fresh specimens and contain less myoglobin and fewer mitochondria
-fast twitch
-fatigue prone
Type IIb fibers
-longitudinally arrayed structural subunit that fill muscle fibers
-extend the entire length of the muscle
myobfibrils
The bundles of myofilaments that make up the myofibril are surrounded by a well-developed, smooth-surfaced endoplasmic reticulum, also called the __________________
sarcoplasmic reticulum
Which bands are dark?
A bands
Which bands are light?
I bands
a dense line bisecting the I band
Z line or Z disc
less dense region that bisects the A band
H band
narrow dense line bisecting the H band
M line
small, polar molecule that polymerizes to form a double-stranded helix, the F-actin filament
G-actin
densely staining cross-bands that cross the fibers in a way that resembles the risers of a stairway; present in cardiac muscle
-highly specialized attachment sites between adjacent cells
intercalated discs
region of cardiac muscle cells where the organelles are concentrated
juxtanuclear region
serves as the site at which the thin filaments in the terminal sarcomere anchor onto the plasma membrane
-holds the cardiac muscle cells at their ends to form the functional cardiac muscle fiber
fascia adherens
-bind the individual muscle cells to one another
-help prevent the cells from pulling apart under the strain of regular repetitive contractions
maculae adherentes
provide ionic continuity between adjacent cardiac muscle cells, allowing informational macromolecules to pass from cell to cell
gap junctions
generate and rapidly transmit the contractile impulse to various parts of the myocardium in a precise sequence
purkinje fibers
