Muscle Tissue (2) Flashcards
Types of muscle tissue
Cardiac, smooth, and skeletal
Where is smooth muscle located
Walls of GI tract, blood vessels, etc
In smooth muscle, what are the shape of the cells
Short and spindle shaped
Nucleus placement in smooth muscle
Centrally placed
Do smooth muscle cells have striations
No
Smooth muscle activity is regulated by…
Autonomic nervous system
Is smooth muscle branched
No, unbranched
Function of smooth muscle
Propels substances or objects
Forms the myocardium of the heart
Cardiac muscle
Tissue is similar to skeletal muscle under microscope
Cardiac muscle
Striations in Cardiac muscle are formed by..
Actin and myosin filaments within microfibrils
Shorter than skeletal muscle cells
Cardiac muscle
Location of the nucleus and features in cardiac muscle
Branched, striated, centrally located nucleus
Unique feature or cardiac muscle
Intercalated discs
Intercalated discs are found where…
Cardiac muscle cells join one other
Promote rapid transmission of impulses through many cardiac muscle cells at once.
Intercalated discs
Cardiac muscle cells are voluntary or involuntary
Involuntary, regulated by ANS
Function of cardiac muscle
Propels blood into circulation
Skeletal muscle is mostly
Voluntary
Shape of cells and nucleus in skeletal muscle
Cylindrical cells, often as long as the muscle itself.
Multinucleate
Why is skeletal muscle striated
Due to overlapping patterns of protein filaments
Cell membrane in skeletal muscle
Sarcolemma
Skeletal muscle cells are full of…
Myofibrils, packed with thin and thick filaments
Actin
Thin filament
Myosin
Thick filament
Composed of repeating segments called sacromeres
Myofibrils
Ends of sacromere
Z disc or Z line
Between two discs, actin and myosin filaments are arranged….
Such that myosin filaments have their heads oriented outwards towards the actin filaments
During contraction in skeletal muscle,
Myosin heads contact actin filaments and draw them towards the center of sacromere to shorten it
Muscle contraction is the result of…
Contraction of many sacromeres in series.
Three types of skeletal muscle connective tissue
Endomysium, perimysium, and epimysium
Connective tissue surrounding a single muscle fiber
Endomysium
Connective tissue surrounding a musicale fasicle
Perimysium
Bundle of skeletal muscle fibers
Fascicles
Connective tissue surrounding an entire muscle
Epimysium
During contraction do the length of thick and thin filaments change
No
Types of muscle contractions
Isometric, eccentric, and concentric
Contraction of a muscle without the muscle changing in length
Isometric
Holding weight in hand, not moving
Isometric
Contraction of muscle while shortening
Concentric
Contraction of muscle while it’s lengthening
Eccentric
Flexing bicep, lowering weight, squatting
Eccentric
Single motor neuron and the muscle fibers it innerverates
Motor unit
Large motor unit
Motor neuron and the many muscle fibers it innervates, strong course movement
Small motor unit
Motor neuron and the few muscle fibers it innervates (very fine, precise movements)
