How many body systems are in the atlas?

Seventeen layers, from the skeleton and muscles to the lymphatic and endocrine systems, joints and ligaments, the body surface and a separate pregnancy reference.

Can I see nerves and vessels under the muscles?

Yes. Lower the opacity of the muscles, or use X-ray mode, and the nerves and vessels beneath stay clickable.

Human body systems in 3D, layer by layer

Peel the body back, system by system.

Turn each body system on or off to build up the anatomy the way you study it: start with the skeleton, add the muscles, then the vessels, nerves and organs. Fade any layer, show one system on its own, or switch to X-ray mode to see deep structures through the surface.

One switch per system: Skeleton, muscles, heart, arteries, veins, nerves, respiratory, digestive, urinary, lymphatic, endocrine and reproductive organs, joints and more.
Opacity for every layer: Make the muscles see-through to follow the nerves and vessels beneath them.
Solo a system: Show a single system, such as the arteries, to trace its branches from the heart to the hand.
X-ray mode: Fade the outer layers so a selected deep structure shows through the body.

The 17 layers

Skeleton: Bones form the supporting framework of the body, protect organs, and provide attachment points for muscles. Their internal tissue also stores minerals and produces blood cells.
Muscles: Skeletal muscles generate movement by pulling on their attachments. Together with tendons, they move joints, stabilize posture, and produce heat.
Heart: The heart is a muscular pump with four chambers. Its valves direct blood forward through the pulmonary and systemic circuits.
Sensory organs: These structures contribute to special senses, including sight, hearing, and balance. Their specialized tissues detect stimuli and work with the nervous system to convey information.
Arteries: The heart drives blood through the circulation. Arteries carry blood away from the heart to supply tissues or, in the pulmonary circuit, to the lungs.
Veins: Veins return blood toward the heart. Superficial and deep networks collect blood from the tissues; the pulmonary veins bring oxygenated blood back from the lungs.
Nervous system: The brain, spinal cord, and peripheral nerves carry and process signals. They support sensation, movement, coordination, and automatic regulation of body functions.
Respiratory: The airways conduct air to the lungs, where oxygen and carbon dioxide move between air and blood. Breathing depends on pressure changes produced by respiratory muscles.
Digestive: The digestive tract breaks down food, absorbs nutrients and water, and moves waste onward. Accessory organs contribute bile and digestive enzymes.
Urinary: The kidneys filter blood and regulate fluid, electrolyte, and acid–base balance. Urine travels through the ureters to the bladder and exits through the urethra.
Lymphatic: Lymphatic vessels return excess tissue fluid to the circulation. Lymph nodes and other lymphoid organs support immune surveillance and responses.
Endocrine: Endocrine organs release hormones into the blood to coordinate processes such as metabolism, growth, stress responses, and reproduction.
Reproductive: The reproductive organs produce germ cells and sex hormones. In the male they produce and carry sperm; in the female they produce ova, receive and nourish a fertilized ovum, and the breasts secrete milk.
Pregnancy reference: Reference structures of a full-term pregnancy: the placenta, amnion and umbilical cord. They are shown separately and hidden by default.
Body surface: The body surface provides an outer anatomical reference. The integumentary system forms a protective barrier and contributes to sensation and temperature regulation.
Connective tissue: Cartilage, ligaments, and other connective tissues support, connect, and separate structures. Their roles include stabilizing joints and distributing mechanical loads.
Joints & ligaments: Ligaments, joint capsules, labra, articular discs, menisci and bursae. Ligaments bind bone to bone; capsules enclose synovial joints; bursae let tendons glide.

Questions

How many body systems are in the atlas?: Seventeen layers, from the skeleton and muscles to the lymphatic and endocrine systems, joints and ligaments, the body surface and a separate pregnancy reference.
Can I see nerves and vessels under the muscles?: Yes. Lower the opacity of the muscles, or use X-ray mode, and the nerves and vessels beneath stay clickable.