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Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...
In some of its facets human anatomy is closely related to embryology, comparative anatomy and comparative embryology, [1] through common roots in evolution; for example, much of the human body maintains the ancient segmental pattern that is present in all vertebrates with basic units being repeated, which is particularly obvious in the ...
The organs, muscles, and other contents of the torso are supplied by nerves, which mainly originate as nerve roots from the thoracic and lumbar parts of the spinal cord. Some organs also receive a nerve supply from the vagus nerve. The sensation to the skin is provided by the lateral and dorsal cutaneous branches.
Human anatomy is the scientific study of the morphology of the adult human. It is subdivided into gross anatomy and microscopic anatomy . Gross anatomy (also called topographical anatomy, regional anatomy, or anthropotomy) is the study of anatomical structures that can be seen by unaided vision.
The human body is the entire structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organs and then organ systems . The external human body consists of a head , hair , neck , torso (which includes the thorax and abdomen ), genitals , arms , hands , legs , and feet .
He could distinguish the human body's sensory and motor nerves and believed air entered the lungs and heart, which was then carried throughout the body. His distinction between the arteries and veins—the arteries carrying the air through the body, while the veins carry the blood from the heart was a great anatomical discovery.
Scientists have discovered which animal was the first to branch off from our collective common ancestor. For years, debate had raged over whether the first to diverge was the sea sponge or the ...
In a 2018 study, carbon was found to compose approximately 550 billion tons of all life on Earth. [ 16 ] [ 17 ] It is the second most abundant element in the human body by mass (about 18.5%) after oxygen.