muscular system Flashcards
(30 cards)
what is the main function of the muscular system?
movement
____ are attached to the bones in our bodies and allow our limbs to move.
muscle
other than movement where else do muscles work?
heart
blood vessels
digestive organs
supports posture and create heat
3 types of muscle
skeletal, cardiac, and smooth (visceral)
how many muscles in the body?
over 600
Where can visceral (smooth) muscle be found?
stomach
intestines
blood vessels
can we consciously control visceral muscles?
no, involuntary muscle
3 properties all muscles have in common?
excitability - electric gradient which can reverse when stimulated
contraction - tissues have ability to contract or shorten
elongate - tissues share the capacity to elongate or relax
what is visceral muscle also called?
smooth muscle because of its smooth surface
where is the only place cardiac muscle is found?
heart
what do cardiac muscles do?
contract and pump blood through the body
can cardiac muscle be controlled?
no, involuntary muscle
is cardiac muscle weak or strong
strong
what is cardiac muscle composed of?
individual muscle cells called cardiomyocytes that are joined together by intercalated discs
what skeletal muscles can be voluntary controlled but usually operate involuntary?
diaphragm and muscles that control blinking
only muscle that contracts and reacts and relaxes by voluntary control?
skeletal muscle
what attaches skeletal muscles to the bone?
tendons
what are tendons formed by?
connective tissue rich in collagen fibers
what are skeletal muscles made out of?
muscle fibers (cells) that are bound together in parallel bundles
what is striated muscle
muscle that has stripped appearance under a microscope
is smooth muscle striated or nonstriated?
nonstriated
each skeletal muscle contains a bundle of?
myofibrils
myofibrils are composed of multiple repeating contractile units called?
sacromeres
myofibrils contain two protein microfilaments:
thick filament and thin filament