The Cutaneous Regions describe regions of the skin and are the most superficial. Su Wen ch. 56 is the main reference point for describing the cutaneous regions and how the skin protects the body from invasion:
"The first emergence of the one hundred diseases begins in the skin and its hair.
When the Evil strikes there, then the interstium (腠理 Cou Li) open.
When they are open, it enters the Blood Vessels (絡脈 Luo Mai) and settles there.
If it stays there and does not leave, it will be transmitted to the Meridians (經 Jing).
If it stays there and does not leave, it will be transmitted to the Bowels (府 Fu) where it settles in the Intestines and Stomach (絡胃Chang Wei) ....
If the Evil invades the skin, the interstitium (腠理Cou Li) will open.
If the Evil invades the Blood Vessels (絡脈Luo Mai), if the Blood Vessels (絡脈Luo Mai) are full, it will be injected into the Meridians (經 Jing).
If the Meridians (經 Jing) are full, it will enter the Fu (府) and Zang (藏) Organs."
The skin acts like the wall to a city, the pores its many gates. The skin is governed by the Lung and is associated with the Wei Qi. They are very closely connected to the Sinews Meridians that lie behind them and the Luo vessels whose health is determined by changes in the colour of the skin. Therefore, the treatments methods that relate to these meridians are ones that open this Exterior barrier to release Pathogens from the body. The primary methods for this are to induce sweating to release Pathogens from the Sinew layer and bloodletting to release them from the Blood. Massage, moxa and liniments that work on the surface to induce changes in skin colour or sweating will also influence them, as can internal herbs. They can also used diagnostically with skin conditions to determine which Divisions and Zangfu are affected, and with what kind of Pathogen, so their root causes can be addressed.
Su Wen ch. 56 provides unique names for each of the divisions of the skin and presents them in a specific order. Both of these imply a certain ordering and pairing. In terms of sequence, the divisions which contain the Earth and Metal elements (Yangming & Taiyin) are placed first and last, while the divisions which contain Fire and Water elements (Taiyang & Shaoyin) are nestled in the middle, leaving the Wood and Ministerial Fire divisions between them (Shaoyang & Jueyin). There are also similarities with the names that imply a special relationship between the pairs based on their Greater (Tai) and Lesser (Shao) attributions. The Yangming and Jueyin both contain the character 害 (Hai, "Harmful"), the Shaoyang and Shaoyin contain 樞 (Shu, "Pivot"), and the Taiyang and Taiyin contain 關 (Guan, "Closing"). This is interesting because the Su Wen ch. 6 says that "Taiyang opens (太陽為開 Taiyang Wei Kai), Yangming closes (陽明為闔 Yangming Wei He), Shaoyang pivots (少陽為樞 Shaoyang Wei Shu) ... Taiyin opens (太陰為開 Taiyang Wei Kai), Jueyin closes (厥陰為闔 Jueyin Wei He) Shaoyin pivots (少陰為樞 Shaoyang Wei Shu)," and while the Shaoyang and Shaoyin pairs agree with this, the Taiyang and Taiyin both contain "closing" in their name instead of "opening." From the use of "harmful" in the Yangming and Jueyin pair's name, it may suggest that these names refer to pathological states rather than physiological ones, in which case the Taiyang and Taiyin, which should open, become pathological when they close, while the Yangming and Jueyin, which should close, enter a pathological state when they open and invite harm inside. The Shaoyang and Shaoyin pair pivot, which can beneficial or harmful, depending on how much the pivot moves, and so the same word can be used for a pathological state as the physiological one.
The front of the body.
The external sides of the body.
樞儒 Shu Ru (Pivot of Cowardice)
The inner sides of the body.
儒 Ru generally means "scholars," especially Confucian ones, but can also imply cowardice. I have chosen this translation to conform with my interpretation of the names as referring to pathological states and this pair belonging to Shaoyin which includes the Kidneys that govern Fear and the Heart that governs the Shen and mental faculties as a whole.
害肩 Hai Jian (Harmful Undertaking)
The inner surfaces of the body and genitals.
肩 Jian literally means "shoulder," but can be used to refer to shouldering a burden and hence and undertaking, which seems to fit this region better.
關蟄 Guan Zhi (Closed Seclusion)
蟄 Zhi can mean "seclusion" or "hibernation."