Xīn 辛 — Pungent → Lung
Metal phase / Lung affinity
Pungent is paired with the Lung and Metal phase in the five-flavor system. The thoracic point is a functional target-organ projection for the Lung network and is not a surface map of respiratory pharmacology.
Point 4 of 5 in Five Flavors → Five-Zang Organ Tropism
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Huangdi Neijing · Suwen (黃帝內經素問) (primary_canonical)
Suwen ch. 23 (Xuanming wuqi) discusses the five qi and five flavors in relation to the zang; ch. 5 supplies the wider five-phase correspondence frame. This is the canonical basis for the flavor-to-organ affinities represented here.
Bensky, Clavey & Stöger, Chinese Herbal Medicine: Materia Medica (secondary)
The materia-medica reference explains how taste and channel-entry language is used in modern clinical classification; the five-flavor organ set remains a classical correspondence, not an anatomical taste map.