BIOL 161 Exam 4

Skeletal Muscle Tissue

Voluntary, striated muscle attached to bones or fascia, multinucleate.

Cardiac Muscle Tissue

Involuntary, striated muscle found in the heart, mononucleate, autorhythmic.

Smooth Muscle Tissue

Involuntary, non-striated muscle found in hollow organs, mononucleate.

Excitability

The ability of muscle tissue to respond to stimuli from motor neurons.

Contractility

The ability of muscle tissue to shorten and generate force.

Extensibility

The ability of muscle tissue to be stretched without damage.

Elasticity

The ability of muscle tissue to return to its original shape after being stretched.

Epimysium

The connective tissue that covers an entire muscle.

Perimysium

The connective tissue that covers fascicles.

Endomysium

The connective tissue that covers individual muscle fibers.

Indirect Muscle Connection

Connection where collagen fibers form a tendon that merges into the periosteum.

Direct Muscle Connection

Connection where collagen fibers of epimysium are continuous with periosteum.

Aponeurosis

Broad sheet of connective tissue to which muscles attach.

Sarcolemma

The muscle cell membrane.

Sarcoplasm

The cytoplasm of a muscle cell containing myofibrils, myoglobin, and glycogen.

Transverse Tubules (T-tubules)

Tube-like structures that penetrate the interior of muscle cells, filled with extracellular fluid.

Sarcoplasmic Reticulum (SR)

The endoplasmic reticulum of muscle cells storing calcium.

Sarcomere

The functional unit of muscle contraction, made up of overlapping thick and thin filaments.

Sliding Filament Theory

Theory that explains muscle contraction as the sliding of filaments past each other.

Neuromuscular Junction (NMJ)

The synapse between a motor neuron and a muscle cell.

End-Plate Potential (EPP)

A depolarization of the muscle cell membrane due to the influx of sodium ions.

Motor Unit

A motor neuron and all the muscle fibers it innervates.

Recruitment

The process of activating more motor units to increase muscle contraction strength.

Aerobic Respiration

A process of ATP production that requires oxygen and produces a lot of ATP.

Anaerobic Respiration

A process of ATP production that does not require oxygen and produces lactic acid.

Creatine Phosphate

A compound used to quickly regenerate ATP from ADP during short, high-intensity exercise.

Excitation-Contraction Coupling

The process of converting an action potential into muscle contraction.