Lab 11: Myology Flashcards
muscle is the only tissue capable of
changing shape and producing tensions through contraction
possess organelles that are capable of utilizing
chemical energy in the bonds of organic molecules to pull intracellular proteins
three distinct types of muscle tissue
skeletal, cardiac, smooth muscle
skeletal muscle
muscle under voluntary control with striated appearance
function of skeletal muscle
move and stabilize skeleton
what is a majority of the muscle mass made of
skeletal muscle
what forms the striated appearance of skeletal muscle?
actin and myosin arranged in irregular uniform overlapping pattern
skeletal muscle is composed of what cells?
multinucleated muscle cells
is skeletal muscle the only tissue consciously controlled?
yes
cardiac muscle
involuntary, striated muscles only found in the heart
cardiac cells are
small, striated, single nucleus, y shaped cells
where do cardiac cells form extensive interconnections with each other?
intercalated discs
how are cardiac cells connected together?
desmosomes, connected at intercalated discs via gap junctions
gap junction in cardiac cells forms connections between
cytoplasm of adjacent cells
what do gap junctions allow cardiac muscles to do?
allow for electrical signals to pass from cell to cell resulting in uniform cardiac contraction
unique part of cardiac muscle
does not require nervous system to stimulate contractions, but specialized cardiac cells set the contraction rate of the heart
pacemaker cells
specialized cardiac cells setting the contraction rate of the heart
smooth muscle
involuntary, nonstriated muscle
where is smooth muscle located?
digestive system, urinary system, wall of blood vessels, glands, reproductive tract
smooth muscle cells
small, spindle shaped, single nucleus
how are skeletal muscles separated?
physically and functionally
how do physical and function skeletal muscle cells separate?
compartmentalization produced by the muscle CT wrappings
3 concentric wrappings of muscle cell
epimysium, perimysium, endomysium
epimysium
outermost layer; separates and surrounds each muscle from its neighboring cell
what type of tissue is epimysium?
dense irregular CT
the epimysium is continuous with
periosteum around bone
how does epimysium form tendon?
extends beyond the muscle forming the attachment site (tendon) of muscle to bone
perimysium
divides muscle into series of internal compartment containing
fasicles
bundle of muscle fibers
endomysium
innermost CT layer surrounding each muscle fiber
muscle contraction
shorten in length its longitudinal axis which produces force and tension
when muscle is arranged at joint it will produce movement if
contraction is strong enough to overpower opposing forces
when muscles contract they are only capable of
pulling
attachment sites
origin, insertion
origin
stationary attachment site
insertion
moving attachment
where does the insertion pull towards during contraction
the origin
