Midway along the length of the muscle fiber
Spaced at regular intervals along each muscle fiber.
Spaced at irregular intervals along each muscle fiber
Near the proximal end of a muscle fiber,
Near the distal end of a muscle fiber.
Midway along the length of the muscle fiber,
Spaced at regular intervals along each muscle fiber
Spaced at irregular intervals along each muscle fiber.
Near the proximal end of a muscle fiber.
Near the distal end of a muscle fiber.
Thick filaments (myosin)
Thin filaments (actin)
T-tubules
Sarcoplasmic reticulum
Neuromuscular junctions
Sarcomeres.
Transverse tubules.
Sarcoplasmic reticulum
Z-lines.
Thick filaments,
Long fiber has a higher velocity during isotonic contraction than the short one
Long fiber has a higher velocity during isometric contraction than the short one
Long fiber has a lower velocity during isotonic contraction than the short one
Long fiber has a lower velocity during isometric contraction than the short one
Both fibers have the same velocity during isotonic contraction
A mutation in the voltage sensuive K+ channel of skeletal muscle
Elevated PIP2 in skeletal muscle
Depressed PIP2 and elevated IP3 in gamma-motoneurons of the penpheral nerves
A mutation in acetylcholine esterase
A mutation in the voltage sensitive Ca2+ channel of skeletal muscle
T tubules are located at the Z disk
T tubules are absent
Troponin is absent
It possesses triads
It possesses caveolae
They are located in the Z disk
They consist of two terminal cisternae of the sarcoplasmic reticulum separated by a T tubule
They can be observed with the light microscope
They are characterized by a T tubule that sequesters calcium ions
They consist of two T tubules separated by a central terminal cisterna
Can be cleaved into light and heavy myoglobin by the proteolytic enzyme papain
Are attached to the Z line by a-actinin
Each has a head component that includes an actin-binding site
Can shorten to half their resting length during contraction
Have tail components that overlap In the I band
T tubule, terminal cisternae, sarcoplasmic retinaculum, sarcolemma
Sarcoplasmic retinaculum, T tubule, presynaptic membrane, sarcolemma
Terminal cisternae, sarcolemma, sarcoplasmic retinaculum, caveolae
Sarcolemma, T tubule, terminal cisternae, sarcoplasmic retinaculum
Sarcolemma, sarcoplasmic retinaculum, T tubule, terminal cisternae
Individual muscle fibers
Muscle fascicles
Individual myofibrils
An entire muscle
Small bundles of muscle cells
Length of the muscle
Number of motor units activated
Peak intracellular calcium concentration in the muscle
Strength of each cross-bridge interaction with actin
Maximum shortening velocity of the muscle
Are found only in cardiac muscle
Are largest in muscles responsible for delicate movements
Consist of a muscle fiber and all the nerves that supply it
Consist of a motor neuron and all the muscles it supplies
Are the same as myoneural junctions
Are evaginations of the sarcoplasmic retinaculum
Sequester calcium ions during muscle relaxation
Carry repolarization to the muscle fiber interior
Are found overlying the A-I band junction in cardiac muscle cells
Contain a rich supply of acetylcholine receptors
Endomysium
Epimysium
Fascia
Perimysium
Sarcoplasmic retinaculum
Differentiation of satellite cells
Dedifferentiation of myocytes into myoblasts
Fusion of damaged myofibers to form new myotubes
Hyperplas ia of existing myofibers
Differentiation of fibroblasts to form myocytes
Botulinum toxin
Muscanne
Atropine
Curare
Pyridostiqmine
To block the Ca++ ATPase activity of cell membrane
To block the Ca++ ATPase activity of scarcoplasmic membrane
To increase the Ca++ entry through DHP receptors
To increase Ca++ release through ryanodin receptors
To increase the activity of Ca++/3Na+ exchanger
Cellular Ca++ storage
Cellular glycogen storage
Glycogen degradation
Transport of Ca++ into the terminal cisternae during muscle contraction
Ca++ release from the transverse tubules during muscle relaxation
Myofilament, myofibril, fiber, fascicle
Fiber, myofibril, myofilament, fascicle
Fascicle, fiber, myofilament, myofibril
Fascicle, fiber. myofibril, myofilament
Fiber. myofibril. fascicle, myofilament
Na+, depotarization
Na+, repolarization
K+, depolarization
K+, repoanzation