Muscular system

What are the two types of protein filaments in the myofibril?

A ____ is the functional units of a muscle and the part of the muscle that contracts.

An involuntary muscle that allows the heart to contract effeciently and rhythmically:

• skeletal muscle

• cardiac muscle

• fibro

• smooth

_____ -twitch muscles fibers have more endurance than other types of muscle fibers and the body of the triathletes have more of them.

In rigor mortis

• ATP is required to pump the actin back out of the myofibril

• ATP is required to pump myosin back out of the sarcomere

• ATP is required to pump the calcium back out of the myofibril

• ADP is required to pump the calcium back out of the myofibril

What causes the case of rigor mortis?

Calcium is needed for the muscle contraction because it

• causes the myosin and actin to attach to ech other

• causes the ATP to upgrade into ADP

• causes the muscles to relax

• causes the myosin-actin repultion

_____, which are tough bands of connective tisuue, connects mucles to bones.