Muscles
Musculi
- Related terms: Muscles; Muscular system
Definition
Muscles are specialized contractile tissues that generate movement. They maintain posture, stabilize joints, and produce body heat.
Anatomically, there are three main types of muscles:
Skeletal muscle: Voluntary, striated muscle attached to bones; responsible for body movements and posture.
Cardiac muscle: Involuntary, striated muscle found only in the heart; enables rhythmic contractions for blood circulation.
Smooth muscle: Involuntary, non-striated muscle found in the walls of hollow organs and vessels; controls internal movements such as peristalsis and vasoconstriction.
Muscles act through contraction initiated by nerve impulses, allowing coordinated motion and vital physiological functions.
There are approximately 650 skeletal muscles in the human body.
References
Dave HD, Shook M, Varacallo MA. Anatomy, Skeletal Muscle. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537236/
Gray, H. (2016) Gray’s anatomy the anatomical basis of clinical practice /. Chapter 5: Functional anatomy of the musculoskeletal system. 41st edition. Edited by S. Standring. New York: Elsevier.
