Chapter 6- The Muscular System

Calcium ions

________ (Ca2+) bind regulatory proteins on thin filaments and expose myosin- binding sites, allowing the myosin heads on the thick filaments to attach.

ATP

________ provides the energy for the sliding process, which continues as long as calcium ions are present.

Irritability

________ (responsiveness)- ability to receive and respond to a stimulus.

Endomysium

________- encloses a single muscle fiber (cell)

Myosin heads

________ are known as cross bridges when they link thick and thin filaments during contraction.

Extensibility

________- ability of muscle cells to be stretched.

Elasticity

________- ability to recoil and resume resting length after stretching.

Epimysium

________- covers the entire skeletal muscle.

Fascia

________- on the outside of the epimysium.

Z disc

Actin is anchored to the ________.

Acetylcholine

________ (ACh) the neurotransmitter that stimulates skeletal muscle.

Myofibrils

________- long organelles inside muscle cell.

Skeletal muscles

________ must be stimulated by a motor neuron (nerve cell) to contract.

adequate stimulus

Contractibility- ability to forcibly shorten when a(n) ________ is received.

Skeletal muscle cells

________ are large, cigar- shaped, and multinucleate.

skeletal muscle cells

Motor unit- one motor neuron and the ________ stimulated by that neuron.

Skeletal muscle \n Cardiac muscle \n Smooth muscle

three basic muscle’s found in the body

to the movement of microfilaments

Contraction and shortening of muscles are due ___

“muscle”

Prefixes *myo-* and *mys-* refer to

“flesh”

Prefix *sarco-* refers to