Microscopic Anatomy of a Skeletal Muscle

Front

A-Band

Back

The dark band in skeletal muscle fibers that contains thick filaments (myosin) and some overlapping thin filaments (actin).

Front

What is the endoplasmic reticulum in a muscle cell called?

Back

Sarcoplasmic reticulum.

Front

What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue?

Back

A bands and I bands.

Front

The H zone, located within the A band, lacks thin filaments and is represented by ________.

Back

D.

Front

Z-Disc

Back

The boundary structure of a sarcomere that anchors thin filaments (actin) and connects adjacent sarcomeres.

Front

What are I bands?

Back

The light bands in skeletal muscle fibers that contain only thin filaments (actin).

Front

What is a sarcomere?

Back

The functional unit of a muscle fiber, defined as the segment between two Z-discs.

Front

What is the role of myosin heads during muscle contraction?

Back

They bind to actin filaments and pull them inward, causing muscle contraction.

Front

What is the function of the sarcoplasmic reticulum?

Back

To store and release calcium ions, which are essential for muscle contraction.

Front

What is the M line?

Back

The line in the center of the A band that anchors thick filaments (myosin).