Library · Anatomy
The skeleton
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An adult person's skeleton usually has 206 bones. Together with cartilage, ligaments, and tendons, they make up about a fifth of your body weight.
The first thing to get out of your head is the idea that bone is dry stone. It is connective tissue, that is, supporting tissue, and it is metabolically active: a tissue that works all the time. That is why it provides structure, protects the vital organs, and, attached to the muscles, works as a system of levers. When a muscle pulls, the bone moves with it, and that is where movement comes from.
But it also stores things. It is a scaffold that also shields what is inside and serves as the body's calcium pantry: when calcium in the blood drops, bone releases its own to cover the shortfall. And inside, in the red marrow, which is the spongy filling of some bones, the body makes most blood cells. So your skeleton is structure, shield, warehouse, and factory all at the same time.
In brief
The adult skeleton usually has 206 bones and, together with cartilage, ligaments, and tendons, accounts for about 20 percent of body weight.
Bone is metabolically active connective tissue: it provides support, protects vital organs, and, with the muscles, works as a system of levers that produces movement.
It also releases calcium when blood levels drop, and most blood cells are made in its red marrow.
A scaffold that also shields what is inside and stocks the calcium pantry.
Sources (3)
- SEER Training Modules, National Cancer InstituteDivisions of the Skeleton, SEER Training Modules
- SEER Training Modules, National Cancer InstituteIntroduction to the Skeletal System, SEER Training Modules
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Bone, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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