Muscle Anatomy and Physiology Flashcards
tendon
a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone
fascia
a sheet of tissue that covers or connects parts inside the body (such as muscles)
epimysium
the outermost fibrous sheath that covers a muscle
Muscular relaxation is caused by
calcium pumps in the lateral sacs of t-tubule pump calcium back into the lumen of SR
myofibrils
series of structures (sarcomeres)
plasma membrane
true cell boundary that maintains acid base balance
why do skeletal muscle fibers have a striated appearance?
due to the banding of thick and thin myofilaments
Sarcomeres
basic functional contractile unit of a muscle
what are the 2 basic parts of a sarcomere
thick and thin filaments
dark bands in striated muscle are due to
the overlap of thick (myosin) and thin (actin) myofilaments.
Light bands are due to
a lesser density and greater penetration of light
myosin heavy chain
molecular weight 200 kilodaltons
myosin light chain
16-28 kilodaltons
thin filament
actin
thick filament
myosin
Muscle work
the sliding of thin filaments over the thick filaments. (isometric, concentric, or eccentric)
isometric
the filaments refuse to move (same length)
concentric
the thin filaments slide towards each other (shortening)
eccentric
the thick filaments try to prevent the thin filaments from sliding apart. (negative)(lengthening)
H-Zone and Z-Line disappear in
contraction
Unique cells
shape length nuclei satellite cells basement membrane polarized sarcolemma
cell dimensions
volume number length radius number of capillaries
