Zoology · Ch 9 — Locomotion and Movement
Types of muscles
9.2
Types of muscles
Types of muscles
Muscle is a specialised tissue that develops from the middle embryonic germ layer, the mesoderm. It is built from elongated, contractile cells called myocytes (muscle cells/fibres), which are bound together by connective tissue into muscular tissue. Muscle is metabolically and mechanically central to the body — it makes up roughly 40-50% of an adult's total body weight, more than any other single tissue type.
Human muscle is classified into three types based on structure, control and location:
- Skeletal muscle — striated, voluntary, attached to bone by tendons; responsible for locomotion and posture.
- Visceral (smooth) muscle — non-striated, involuntary; lines hollow internal organs such as the gut and blood vessels, producing slow, sustained contractions like peristalsis.
- Cardiac muscle — striated but involuntary; found only in the heart wall, contracting rhythmically and tirelessly throughout life without ever fully fatiguing. …