Introduction to Muscle Cells and Muscle Fibers

Comprehensive practice flashcards covering muscle anatomy, wrappings, cell structures, and signaling pathways from the introductory lecture.

What initiates excitement in muscle tissue to allow for contraction?

Nerve impulse transmission, where chemicals bind to receptors to open channels and usher in a nerve impulse.

What type of impulses communicate with muscles and spread through their structures from the nervous system?

Electrical impulses.

What is the ultimate goal of any muscle stimulation?

To make the muscle contract and get shorter.

What structures create the light and dark striations seen in skeletal muscle under a microscope?

Thick and thin bands of myofilaments (muscle fibers).

How is skeletal muscle movement controlled?

It is voluntarily controlled.

What connective tissue structure surrounds an individual muscle cell or muscle fiber?

Endomycium.

What is a muscle fascicle?

A group or collection of muscle cells wrapped together that all contract at once to achieve whole muscle movement.

Which connective tissue wraps up a muscle fascicle?

Paramyseum.

What connective tissue surrounds the entire muscle itself?

Epimysium (also referred to as fascia).

What is the primary function of tendons?

To connect muscle to bone.

Which specific tendon is noted as linking muscle of the foot up to the calf?

Achilles tendon.

What is the name of the plasma membrane of a muscle cell?

Sarcolemma.

What is the name for the semi-liquid cytoplasm of a muscle cell?

Sarcoplasm.

In what polysaccharide form is glucose stored in the muscle cytoplasm to help produce ATP?

Glycogen.

Which pigment protein carries and stores oxygen inside the muscle fiber?

Myoglobin.

What specialized structure acts as a modified smooth endoplasmic reticulum in muscle cells?

Sarcoplasmic reticulum.

Which key cation is stored inside the sarcoplasmic reticulum to activate muscle contraction?

Calcium ion.

Where do terminal cisterns lead?

To transverse or T tubules.

What is the function of transverse (T) tubules?

They go down inside the sarcolemma to allow nerve impulses to travel inside the muscle fiber and activate muscle contraction.