Development of Muscular System of Animals
The muscular system consists of specialised cells – the muscle fibres which are of three varieties, skeletal, plain and cardiac.
These are differentiated from the myoblasts which are derived from the mesoderm. The smooth muscle fibres of the iris and sweat glands are ectodermal.
The muscles originate in the myotomes. The visceral (plain and cardiac) musculature is developed from the splanchnic mesoderm that surrounds the gut and heart.