This atlas takes the BodyParts3D reference anatomy apart into 2,234 individually selectable pieces grouped into 15 systems. Orbit, zoom, toggle systems, search a structure by name, isolate it, or explode the whole body into its parts.
Explore the 3D body atlas4 structures
Among other roles, skin shields the body, limits water loss and senses its surroundings; the group includes skin, scalp hair, eyebrows and lips.
Skin guards the body against wind, water and UV sunlight and forms a barrier against water loss. Skin, and especially the hairs growing from its follicles, can also sense changes in the surroundings. The skin and its accessory structures also help regulate body temperature and electrolyte balance, and they make vitamin D. In this model the body-surface group consists of the skin, scalp hair, eyebrows and lips.
278 structures
Holds the body up, helps it move, shields organs, stores minerals and makes blood cells; the model also files the teeth and gums here.
Bones hold the body up, help it move and shield its organs; when a muscle contracts across a joint, the bone works as a lever. The bone matrix is a store of minerals, notably calcium and phosphorus; red marrow is where blood cells are made, and the fat held in yellow marrow can serve as an energy reserve. In this model the skeletal group also includes the teeth and gums.
416 structures
Skeletal muscles create and stop movement, hold posture, keep joints from overmoving, and give off heat as they contract.
Skeletal muscles do more than create motion: they also stop it, for instance by working against gravity to hold a posture, and they keep bones and joints from moving too far. The heat they give off as they contract is one of their contributions to homeostasis.
45 structures
Connective tissue supports and joins other tissues, and ligaments hold bones together at joints. The group is mainly ligaments, tendons and membranes.
Connective tissues have many roles, but above all they support and connect other tissues; tendons, for example, attach muscles to bones. Ligaments, tough bands of fibrous connective tissue, bind bones together at joints; they permit normal joint movement but restrict its range, which prevents excessive or abnormal motion. In this model the connective group is mainly ligaments, tendons and membranes such as the interosseous membranes of the forearm and leg.
18 structures
The heart's two ventricles do the main pumping, sending blood to the lungs and around the body, while valves keep the flow one-way.
The heart has four chambers, and its two ventricles do the main pumping, driving blood either to the lungs or around the rest of the body. Its valves keep blood moving through it in a single direction. In this model the heart appears mainly as the cavities of its chambers and the cusps and leaflets of its valves.
636 structures
Arteries carry blood away from the heart, branching down to capillaries where nutrients and wastes change places.
Arteries take blood away from the heart and divide into smaller and smaller vessels: arterioles, then capillaries, where nutrients and wastes are exchanged. Systemic arteries deliver oxygen-rich blood to the body's tissues; in the pulmonary circuit, by contrast, arteries carry oxygen-poor blood, and only to the lungs, for gas exchange. Their walls are thicker than those of veins, since they lie closer to the heart and take blood surging at much higher pressure.
475 structures
Veins bring blood back to the heart; many, especially in the limbs, have valves that stop it flowing backward.
Veins bring blood back toward the heart. Because they are low-pressure vessels, many of them, especially in the limbs, have valves that help blood flow one way, toward the heart, and prevent it from flowing backward. The pulmonary veins carry blood that has just taken up oxygen in the lungs back to the heart.
386 structures
Takes in, integrates and responds to information. The model includes the brain, spinal cord and peripheral nerves such as the sciatic, median and ulnar nerves.
The brain and spinal cord make up the central nervous system; everything else, the nerves and ganglia, forms the peripheral nervous system, although where the line between the two falls can depend on which aspect of the system is being considered. Its basic functions are sensation, integration and response: it takes in information about our surroundings, integrates it, and produces responses.
43 structures
Specialized receptors pick up stimuli; the model has the eyeball, tear apparatus and external ear, but no middle or inner ear.
Sensation starts when a stimulus activates specialized receptor cells. In this model the sensory group is mostly the eyeball and its parts (cornea, iris, lens, retina), the tear apparatus, and the external ear; the middle and inner ear are not included.
124 structures
Airways carry air to the lungs, where alveolar sacs swap oxygen and carbon dioxide.
The respiratory system has two zones: a conducting zone of organs not directly involved in gas exchange, and a respiratory zone, where gas exchange takes place in alveolar sacs. The main job of the lungs is to swap oxygen and carbon dioxide with outside air.
103 structures
A one-way digestive tube and its accessory organs break food down; nutrients enter the body by being absorbed.
The digestive organs fall into two groups: the alimentary canal, a one-way tube whose main role is to nourish the body, and the accessory digestive organs, which are critical to breaking food down and to bringing its nutrients into the body. Nutrients only truly enter the body once they are absorbed.
6 structures
Kidney nephrons clean the blood; urine runs down the ureters to the bladder and leaves through the urethra.
The kidneys' nephrons clean the blood and keep its make-up balanced. Waves of peristalsis push urine down the ureters into the bladder, and the urethra then takes it out of the body. The kidneys are also where vitamin D must be hydroxylated to become active, and they make most of the circulating EPO, a protein that stimulates red blood cell formation in the bone marrow.
169 structures
Returns excess fluid to the blood and filters out pathogens; the model has lymph vessels and nodes, the thymus and the spleen.
The lymphatic system, made of vessels, cells and organs, returns excess fluid to the bloodstream and filters pathogens out of the blood. Besides lymph vessels and nodes, the model contains the thymus, where T cells do most of their maturing, and the spleen, a major secondary lymphoid organ.
9 structures
Ductless glands release hormones, which travel mainly in the blood; the model has the pituitary, pineal, thyroid, parathyroid and adrenal glands.
Endocrine glands have no ducts: they release hormones into the surrounding fluid, and the bloodstream is the main route that takes them to target cells throughout the body. In this model the endocrine group holds the pituitary, cradled in the sella turcica of the sphenoid bone; the pineal gland, which secretes melatonin; the two adrenal glands on top of the kidneys, one of whose major jobs is responding to stress; and the thyroid and parathyroid glands.
12 structures
The model is male: the testes make sperm and androgens, and ducts and glands carry the sperm on and form semen.
The model is male, so only male reproductive organs are present. This system makes sperm and transfers them to the female reproductive tract. The paired testes produce both sperm and androgens; sperm mature in the epididymis and exit through the ductus deferens, while the seminal vesicles and prostate contribute fluids that form semen.
System descriptions: written by Sciencepedia from facts in Anatomy and Physiology 2e (OpenStax, CC BY-NC-SA 4.0), sections 4.3, 5.3, 6.1, 9.4, 10.2, 12.1, 14.1, 17.1, 17.3, 17.6, 17.7, 19.1, 20.1, 21.1, 22.1, 22.2, 23.1, 25.2, 25.3, 25.10, 27.1 · reviewed by the Sciencepedia editorial board
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