The muscular system Flashcards

what are the functions of the muscular system?

the ability to respond to a stimulus

The ability to shorten when stimulated

the ability to lengthen or stretch, even past their original shape

the ability to recoil or bounce back to the original shape and length after being stretched

connects to bones

Cylindrical
• Striated (muscle
fibers have stripes)
• Multinucleated
• Voluntarily
controlled
• Contracts slowly or
very quickly

Found in heart
• Branched
• Striated
• Uninucleated
• Involuntarily
controlled
• Mostly slow and
steady contractions except during short periods of activity

Found in walls of internal organs (ex: stomach)
• Arranged in uniform layers
• Nonstriated
• Uninucleated
• Involuntarily
controlled
• Slow contractions,
sustained for long periods of time

Skeletal muscle is attached to bone by tendons

-Made of many bundles of fibers

Bundles within muscles

Long, thin muscle cells

-Each is covered by sarcoplasmic reticulum, which transmit an impulse to the muscle fiber

-Thread-like organelles of the muscle fibers

-Structured in long, striated units called sarcomeres

2 types of filaments: actin (thin) & myosin (thick) make up the sliding filament model of the muscle

-Responsible for contracting activity of muscle fibers

the membrane that covers the whole muscle

membrane that covers a fascicle

membrane that covers an individual muscle fiber

space between two Z-lines

____ and ____ filaments work together to produce a muscle contraction.

• Nerve impulses are sent to the muscle fibers to begin contraction.
• Myosin filaments have rounded extensions called heads. These heads attach to the twisted actin filaments and pull on them. The Z-lines get closer together, and the sarcomere gets shorter.

energy required for the sliding filament theory

ATP is formed through ___ ____.

Cellular respiration depends on the presence of ______.

Step one of muscle fatigue

muscles are worked strenuously and the glucose supply is exhausted.

Step two of muscle fatigue

ATP is no longer efficiently being used for cross-bridges

Step three of muscle fatigue:

Muscles begin to burn, causing you to stop exercising before cells are injured

Step four of muscle fatigue

A difference occurs between the amount of oxygen available and the amount required and you are “out of breath”

Muscles are attached to bones by ____.

The attachment of the tendon to the more stationary bone is called the _____.

The attachment to the more movable bone is called the ______.

the middle of the muscle

muscle doing the action

muscles that help in that same direction

opposing muscle relaxing during motion