-
a band
The component of the sarcomere that appears darker because it contains thick filaments and areas in which the thick and thin filaments overlap.
-
Actin
A bead-shaped contractile protein found in muscle fibers and motile cells
-
Elastic Filamet
A myofilament that consists of the structural protein titin.
-
Endomysium
meaning within the muscle, is a wispy layer of areolar connective tissue that ensheaths each individual myocyte
-
Epimysium
a sheath of fibrous elastic tissue surrounding a muscle.
-
i band
The component of the sarcomere that appears lighter because it contains only thin filaments.
-
h zone
the zone of the thick filaments that is not superimposed by the thin filaments.
-
m line
the attachment site for the thick filaments
-
Motor End Plate
The specialized region of the skeletal muscle fiber plasma membrane that contains receptors for acetylcholine.
-
Muscle Fiber
An alternate name for a skeletal muscle cell.
-
Myofibril
Long, cylindrical organelles composed of muscle proteins in a muscle fiber.
-
myosin
A club-shaped contractile protein found in muscle fibers and motile cells
-
neuromuscular junction
The location where a neuron communicates with a muscle fiber.
-
Sarcolemma
The plasma membrane of a muscle fiber.
-
Sarcomere
The functional unit of muscle contraction; consists of the area of the myofibril from one Z-disc to the next Z-disc.
-
Sarcoplasmic Reticulum
The specialized smooth endoplasmic reticulum of a muscle fiber that stores calcium ions.
-
terminal Cisternae
Enlarged regions of the sarcoplasmic reticulum where it contacts T-tubules.
-
thick filament
A myofilament composed of many molecules of the protein myosin.
-
thin filament
A myofilament composed of molecules of the proteins actin, troponin, and tropomyosin.
-
triad
the structure formed by a T tubule with a sarcoplasmic reticulum (SR) known as the terminal cisterna on either side.
-
tropomyosin
a protein involved in muscle contraction. It is related to myosin and occurs together with troponin in the thin filaments of muscle tissue.
-
troponin
a complex of muscle proteins which, when combined with Ca++, influence tropomyosin to initiate contraction.
|
|
