Muscular System

Striated involuntary muscle tissue is classified as __________ muscle

• skeletal

• smooth

• cardiac

• either smooth or skeletal

The ______ is an organelle that wraps and surrounds the myofibril and stores calcium.

• sarcolemma

• cross bridge

• sarcoplasmic reticulum

• sarcomere

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as _________.

• irritability

• elasticity

• contractility

• extensibility

The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction is called the _________.

• synaptic cleft

• cross bridge

• motor unit

• H zone

Contractions in which muscles shorten and produce movement are known as ________.

• resistance exercises

• isometric contractions

• twitches

• isotonic contractions

Muscles that perform opposite actions to one another are termed _______.

• prime movers

• antagonists

• fixators

• synergists

Striated involuntary muscle tissue found in the heart is ______.

• dense irregular

• smooth muscle

• dense regular

• skeletal muscle

• cardiac muscle

Endomysium covers ________.

• an individual muscle cell

• fascicles of muscle cells

• myofibrils

• an entire muscle

• smooth muscle only

The plasma membrane of a skeletal muscle cell is called the __________.

• sarcoplasm

• sarcolemma

• sarcomere

• myofilament

• sarcoplasmic reticulum

Smooth muscle cells are _________.

• branched

• cylindrical

• involuntary

• striated

• multinucleate