anatomy · section one
the skeleton
206 bones · 237 joints
Point at the drawing, or search for a bone by any name you know it by. Choosing one marks it in ink and turns everything it joins onto green, because a bone on its own tells you almost nothing — what it does is decided by what it is attached to.
green marks what it joins onto
“hip bone. two of them.”
appendicular skeleton · pelvis
Hip bone
Os coxae · two of them · also called pelvic bone, hipbone, innominate bone
It carries the weight of your upper body from the spine out into the legs and gives the hip and buttock muscles a wide surface to pull against. Rest your hands on your hips and the curved ridge under your palms is its upper rim, while the two hard bones you sit on are its lower edge.
it starts as three separate bones that only fuse together inside the hip socket in the mid-teens
what it joins onto
- sacroiliac jointsynovial plane joint bound by very strong ligamentsa few millimetres of give, and no more
- pubic symphysis, where the two hip bones meet in frontcartilaginous symphysisalmost none - it softens late in pregnancy
- hip jointsynovial ball-and-socketball-and-socket - swings the thigh in any direction
62 entries, 206 bones