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gluteus maximus

largest muscle in body which connects the femur and the pelvic girdle


the strongest muscle in body which allows humans to open and close their mouths


a disease in which the masseter tightens and won't open. It is also called lockjaw.

rapid eye movement sleep (REM sleep)

part of the sleep cycle where your eyes move

skeletal muscles

attach to bones and allow you to move

voluntary muscles

muscles you can control by thinking about controlling them

reflexive action

when voluntary muscles move without any thought coming from your brain

muscle tone

when muscles are partly contracted


strong, flexible fibers that attach bones to skeletal muscles


a painful occurrence when tendons get inflamed from overuse

antagonistic muscles

pairs of muscles that work together so that when one muscle contracts, the other relaxes

extensor muscles

these muscles open the joint wider

flexor muscles

these muscles close the joint

biceps brachii

muscle on the top of the arm

triceps brachii

muscle on the bottom of the arm


when a muscle becomes weak and shrinks when it is not used much

muscle fibers

skeletal muscle cell that are long and thin


strands of protein


even smaller strips of cells inside the myofibrils




the stripes in skeletal muscles


a sugar used in your body


a special substance that carries nutrients throughout you body


when a person is unable to move a part of their body


when working cells no longer are using oxygen


energy production that uses oxygen

lactic acid

a waste product from your cells that can cause cramping

cardiac muscles

found in the heart; involuntary muscles

smooth muscles

these muscles have no striations or stripes; they can be found in blood vessels, stomach, intestines or bladder

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