5: Muscle Flashcards
Striated muscle
regular arrangement of actin and myosin filaments gives a highly ordered appearance
What 2 types of muscle are striated?
skeletal and cardiac
Smooth muscle
in walls of tubular organs and blood vessels, not striated
Sarcoplasm
cytoplasm of muscle
Sarcoplasmic reticulum
endoplasmic reticulum of muscle
Sarcolemma
plasmalemma of muscle
T/F: Skeletal muscle is multinucleated
T
Sarcomere
functional unit of muscle
Order from smallest to largest of muscle arrangements
myofilament, sarcomere, myofibril, muscle fiber, fascicle, muscle
A-bands
dark
I-band
light
What are located between the myofibrils throughout the muscle fiber?
mitochondria and glycogen granules
What is between z-lines?
sarcomere
Triad
2 components of sarcoplasmic reticulum and T tubule
Epimysium
surrounds entire muscle tissue
Endomysium
covers each single muscle fiber
Perimysium
surrounds each bundle of muscle fibers
Where are fibroblasts located?
endomysium
Motor end plates
specialized areas where axon branches of somatic efferent neurons make synaptic contact with muscle fibers
Junctional folds
increases surface area due to the sarcolemma being highly folded
Motor unit
the muscle fiber innervated by 1 neuron
Muscle spindles
specialized muscle receptors that sense degree of stretch
Intrafusual fibers
connective tissue capsule surrounding a few muscle fibers
T/F: Cardiac muscle is smaller than skeletal muscle
T
Where are T tubules located in cardiac muscle?
z-lines rather than A-I junction
Diads
1 T-tubule and one SR cisternae
Intercalated disks
in cardiac muscle to connect adjacent cells and allow communication
Where is smooth muscle located?
arteries, GI tract, reproductive tract, iris of eye
Caveolae
vesicles with receptors and ion channels located near SR
Dense bodies
dark staining patches in the cytoplasm and along the cell membrane
What serves as anchor point for actin filaments and intermediate filaments?
dense bodies
What type of junction is found between adjacent muscle cells?
gap junctions
