Human body systems
The atlas groups 2,234 modelled structures into 15 body systems. Choose a system to read its overview and browse the structures that have study pages.
Skeletal system
The skeletal system provides the rigid framework of the body. Bones protect vital organs, act as levers for muscles, store calcium and phosphate, and contain marrow that produces blood cells.
20 pages
Muscular system
Skeletal muscles convert chemical energy into movement. They attach to bones through tendons, and each muscle is described by its origin, insertion, nerve supply and action.
46 pages
Heart and cardiac structures
The heart is a four-chambered muscular pump. The right side sends blood to the lungs, and the left side sends oxygenated blood to the rest of the body. Valves keep blood moving in one direction.
1 pages
Nervous system
The central nervous system comprises the brain and spinal cord. Cranial and spinal nerves form the peripheral nervous system, carrying sensory information to the centre and motor commands to muscles and glands.
3 pages
Arteries
Arteries carry blood away from the heart. The aorta gives rise to progressively smaller branches that supply the head, limbs and organs, while the pulmonary arteries carry deoxygenated blood to the lungs.
2 pages
Veins
Veins return blood to the heart. Superficial veins lie under the skin, deep veins accompany arteries, and valves in many veins prevent backflow.
2 pages
Respiratory system
The respiratory tract conducts air from the nose and mouth through the larynx, trachea and bronchi to the lungs, where gas exchange takes place in the alveoli.
2 pages
Digestive system
The digestive tract runs from the mouth to the anus. Accessory organs such as the liver, gallbladder and pancreas add bile and enzymes that help break down food.
7 pages