muscle tissue Flashcards
what are the three types of muscle tissue and their characteristics
skeletal - voluntary striated
cardiac - involuntary striated
smooth - involuntary, non-striated
skeletal muscle histological appearance
cells look like fibres as elongated and cylindrical
multiple peripheral nuclei
where is skeletal muscle found
attached to the skeleton to allow movement
how is muscle attached to the skeleton
mostly via tendons although some directly to the bone
fasicles
bundle of structures - e.g group of muscle fibres
endomysium
surrounds individual muscle cells
perimysium
surrounds groups of muscle cells (fascicles)
epimysium
surrounds entire muscle tissue
sarcomeres
contractile units of striated muscle
what divides myofibrils into sarcomeres
z lines
is actin the thick or the thin filament
thin, light band
by what mechanism do sarcomeres contract
sliding filament mechanism
sarcolemma
membrane enveloping skeletal muscle fibres
function of t tubules in muscle contraction
conduct impulses from the sarcolemma to the sarcoplasmic reticulum where calcium is stored
what is cardiac muscle specialised for
continuous autonomous contractions
histology of cardiac muscle cells
elongated cylindrical striated cells that can be branched, one or two central nuclei
what are the three layers of the heart
pericardium - outer connective tissue layer
myocardium heart muscle layer
endocardium - thin inner epithelial lining
intercalated disc
specialised junctions allowing coordinated contractions in cardiac muscle
where is smooth muscle found
lining hollow organs e.g stomach, lungs, blood. vessels
histology of smooth muscle cells
small, elongated tapered end cells with a single central nucleus
arrangement of actin and mysoin in sooth muscle
actin and myosin are arranged in a criss cross lattice and anchored to the cytoplasm by focal densities
focal densities
anchor actin and mysoin to the cytoplasm in smooth muscle
