Glossary
muscle tissue
Muscle tissue shortens to produce movement, and its three kinds — skeletal, smooth and cardiac — differ in where they are and whether they obey you.
Muscle tissue produces movement by shortening, and it does that in three forms. Skeletal muscle moves the body, is striated, and is under voluntary control. Smooth muscle lines the walls of hollow organs — the gut, blood vessels, the bladder — is not striated, and works without being told to. Cardiac muscle is the heart's own: striated like skeletal muscle, involuntary like smooth, and able to hold a contraction long enough to empty a chamber. Striation comes from the ordered overlap of the proteins that slide past each other, so a striated fiber contracts in a visible banded pattern and a smooth one does not. Muscle pulls, it never pushes, which is why skeletal muscles work in opposing pairs around a joint. A question asks which kind sits where, and whether the person controls it.
Taught in
Related terms
- tissue — A tissue is a group of similar cells with a shared job and the material between them — the level between a cell and an organ.
- nervous tissue — Nervous tissue carries electrical signals: neurons generate and conduct them, and glial cells insulate, feed and support the neurons.
- sarcomere — A sarcomere is one repeating contractile unit of a muscle fiber, running from one Z line to the next, and it is the part that shortens in a contraction.
Source: The anatomy and physiology guide in this course, whose organ and tissue descriptions follow the US National Cancer Institute's SEER Training Modules and MedlinePlus consumer health pages. Both are US federal government material, not subject to copyright in the United States. The definition above is written for this course in our own words. (SEER Training Modules accessed 2026-10-26; definition written 2026-10-27)