LECTURE 1 muscle tissue Flashcards
functions of muscle tissue (4)
movement (main function), maintenance of posture, joint stabilization, generates heat (thermoregulation)
muscle cells
elongated (called fibers), contain many myofilaments (actin and myosin)
types of muscle tissue (3)
skeletal, cardiac, smooth
special features of muscle (4)
contractibility, excitibility, extensibility, elasticity
contractibility
cells generate pulling force
excitibility
nervous impulses travel through muscle plasma membrane to stimulate action
extensibility
after contraction, muscle can be stretched back to original length by opposing muscle action
elasticity
after being stretched, muscle passively recoils to resume its resting length
skeletal muscle qualities
voluntary function with a few exceptions; attached to bones, fascia, skin; have origin and insertion
cells of skeletal muscle
long and cylindrical in bundles, multinucleate, obvious striations
CT components of skeletal muscle
enomysium (surrounds fibers), perimysium (surrounds bundles), epimysium (surrounds the entire muscle)
cardiac muscle qualities
involuntary function, forms myocardium layer of heart wall that pumps blood through vessels, lots of mitrochondria for energy so muscle can’t fatigue
cells of cardiac muscle
branching chains of cells, single or binucleate, striations, connected by intercalated discs (tight cell junctions, same direction as striations)
CT component of cardiac muscle
endomysium (surrounding cells)
smooth muscle qualities
involuntary function (2 layers in opposite directions that perform peristalsis, churning, segmentation, dilation/constriction), found in hollow organs
