Spindle-shaped cells with central nuclei, no striations
B. Smooth Muscle
Long, cylindrical, unbranched, multinucleated cells; nuclei located toward the periphery of the cell
B. Skeletal muscle
Striated; cells are uninucleated & branched; nuclei are centrally located
C. Cardiac Muscle
Which of the following is not a function of Skeletal muscle?
C. Sensory Detection
Muscle returns to its original shape after contraction or extension
B. Elasticity
Muscle extends (stretches)
C. Extensibility
Muscle contracts (shortens and thickens)
B. Contractility
Muscle receives and responds to stimuli (environmental changes inside or outside the body)
C. Excitability
A muscle fiber is the same as a fiber found in connective tissue.
A. True
B. False
B. False (different)
Individal muscle fiber = a muscle cell
A. True
B. False
A. True
What is the plasma or cell membrane of a muscle cell
D, Transverse (T) Tubules
E. Myofibrils
B. Sarcolemma
Cylindrical structures that run longitudinally through the myofiber; composed of thin and thick myofilaments
A. Sarcolemma
B. Sarcoplasm
C. Sarcoplasmic Reticulum
D, Transverse (T) Tubules
E. Myofibrils
E. Myofibrils
Form of smooth endoplasmic reticulum; regulates intracellular levels of cascium
D, Transverse (T) Tubules
E. Myofibrils
B. Sarcoplasmic Reticulum
Cytoplasm; contains many nuclei. Contains large amounts of stored glycogen & a unique oxygen binding protein called myoglobin
D, Transverse (T) Tubules
E. Myofibrils
C. Sarcoplasm
Tunnel-like extensions of the sarcolemma tha ope to the exterior of the myofiber, found at each A-1 junction
A. Sarcolemma
B. Sarcoplasm
C. Sarcoplasmic Reticulum
D, Transverse (T) Tubules
E. Myofibrils
D. Transverse (T) Tubules
The 3 proteins actin, tropomyosin, & troponin are part of which myofilaments
A. Thick
B. Thin
B. Thin
Predominant protein; the backbone of each thin filament is formed by two strands of actin that coil around each other (looks like a twisted double strand of pearls); the actin molecule contains a myosin-binding site for a myosin molecule
A. Actin
Tropomyosin spirals around the actin backbone; in the absence of calcium, tropomyosin blocks myosin from binding to actin.
B. Tropomyosin
Complex of three protein molecules; one
binds to actin, another binds to tropomyosin, & the third binds to calcium ions; when calcium is present, troponin moves tropomyosin out of the way so that myosin can bind to actin.
C. Troponin
What is the smallest contractile unit of a muscle cell
Sarcomeres
The number of myofibers per motor unit is higher in muscles that exert fine control and higher in muscles whose movements are less precise.
A. True
B. False
False
Which of these structures is not part of a neuromuscular junction?
E. all are part of junction
The 3 major processes of skeletal muscle cell contraction are:
A. Excitation/Inhibition
B. Excitation
C. Mechanism of contraction
D. Excitation/Contraction Coupling
