Aṭṭhī
Bones
Aṭṭhī — the bones, the structural skeleton of the body. Visuddhimagga VIII.92 catalogues the standard Pali enumeration of bones (about three hundred in the Theravāda count) and instructs the meditator to assemble the entire skeleton mentally as the substrate of the rest of the body's contemplated parts. This is the 'central axis' part: the bones are what the rest of the body hangs from. We render the rendered point at the xiphoid-process landmark, a central-axis skeletal locus midway between the chest and the abdomen.
Point 5 of 8 in Theravāda 32 Parts of the Body (Dvattiṃsākāra)
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Majjhima Nikāya 10.10 (primary_canonical)
“In this body there are head hairs, body hairs, nails, teeth, skin, flesh, sinews, bones, bone marrow, kidneys, heart, liver, diaphragm, spleen, lungs, large intestines, small intestines, contents of the stomach, feces, bile, phlegm, pus, blood, sweat, fat, tears, grease, saliva, mucus, oil of the joints, and urine.”
MN 10.10 names bones (aṭṭhī) eighth in the body-parts list. The canonical passage supplies the contemplative inventory; its detailed grouping and visualization are developed later by Buddhaghosa.
Visuddhimagga VIII.92 (primary_canonical)
Visuddhimagga VIII.92 treats the bones in Buddhaghosa’s detailed exposition of the 32 body parts, specifying the object’s characteristic appearance and its place in the sequential training of body-part contemplation.