Topic 6.4 - Muscle Structure24

Front

What is the Epimysium?

Back

The Epimysium is a connective tissue sheath that surrounds the entire muscle, providing structure and support.

Front

What is the function of the Sarcoplasmic Reticulum?

Back

The Sarcoplasmic Reticulum is a specialized endoplasmic reticulum in muscle cells that stores and releases calcium ions, crucial for muscle contraction.

Front

What is Actin?

Back

Actin is a protein that forms thin filaments in muscle fibers and plays a key role in muscle contraction.

Front

What is a Myofibril?

Back

Myofibrils are long, thread-like structures within muscle cells that contain the contractile proteins actin and myosin.

Front

What is the I band in muscle structure?

Back

The I band is a region in a sarcomere that contains only thin filaments (actin) and appears lighter under a microscope.

Front

What is the role of Myosin in muscle contraction?

Back

Myosin is a thick filament protein that interacts with actin to produce muscle contraction through a sliding filament mechanism.

Front

Define Sarcomere.

Back

A sarcomere is the basic functional unit of a muscle fiber, defined as the segment between two Z lines.

Front

What is the function of the Z line?

Back

The Z line marks the boundary between adjacent sarcomeres and anchors the thin filaments (actin).

Front

What is the A band?

Back

The A band is the dark region of a sarcomere that contains both thick (myosin) and thin (actin) filaments.

Front

What is the role of Troponin in muscle contraction?

Back

Troponin is a protein that binds calcium ions and helps regulate muscle contraction by moving tropomyosin away from actin binding sites.