Asthi dhātu — bone proxy
Fifth tissue / skeletal support
Asthi dhātu is placed over a leg proxy so the dense skeletal category can be distinguished from the preceding soft tissues. The coordinate is a target-organ projection for a substance classification and must not be read as a surface diagnosis of bone.
Point 5 of 7 in Dravyaguṇa — Seven Dhātu Affinity
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Caraka Saṃhitā (primary_canonical)
The dhātu sequence names asthi as bone and discusses its formation after meda; the lower-limb proxy is editorial and not supplied as a plotted locus.
Vasant Lad, Ayurveda: The Science of Self-Healing (secondary)
Modern teaching explanation of asthi dhātu as the skeletal tissue; a leg point is used only as an easily read target-organ proxy.