celldiagram.worldBiology · Specialized Cell
Muscle Cell Diagram
A skeletal muscle cell is a long multinucleate fiber packed with repeating protein machinery for contraction.
Interactive vector diagram — click a part, hide labels, or download a 300 DPI PNG / editable SVG.
Diagram labels and functions
| Structure / stage | Function |
|---|---|
| Sarcolemma | Cell membrane around a muscle fiber. |
| Myofibrils | Parallel bundles that shorten during contraction. |
| Sarcomere | Repeating contractile unit. |
| Actin | Thin filament pulled during contraction. |
| Myosin | Motor protein in thick filaments. |
| Mitochondria | Supply ATP for repeated contraction. |
Inside a muscle fiber
Myofibrils run the length of the cell and are divided into sarcomeres. Within each sarcomere, myosin pulls actin inward.
Why muscle cells need ATP
ATP powers cross-bridge cycling and ion pumps. Muscle cells therefore contain many mitochondria and store glycogen.
Related diagrams
Frequently Asked Questions
Why is a muscle cell long?
Its elongated shape lets force develop along many repeating sarcomeres.
What is a sarcomere?
The repeating contractile unit between two Z lines in striated muscle.
Why are there many mitochondria in muscle cells?
Contraction and ion transport require a continuous ATP supply.
Search terms covered by this page
muscle cell diagram