The Physical Anatomy page describes the body Western medicine can measure — bones, muscles, fascia, nerves, breath. This page describes a different body. Not a different organ — a different map: the one yoga built over centuries by paying close attention to what practice actually feels like from inside.
The two maps don't compete. They describe the same territory in different vocabularies, and they're useful for different things. Anatomy tells you why a hamstring resists. Subtle anatomy tells you what it's like to breathe into one. Both are true; neither is the whole story.
A note before we start, said once so we don't keep returning to it. Where the two maps seem to line up — and they sometimes do — we'll call it resonance, not equivalence. The yogic channel called ida is associated with the calming, cooling, receptive side of experience, and modern physiology has the parasympathetic nervous system, which does something similar. That's a real resonance worth noticing. It is not a claim that ida is the parasympathetic nervous system. The traditions developed independently, looking at the same human, finding patterns that sometimes rhyme. Hold the rhyme lightly.
This page lays out yoga's inner map — five sheaths, three channels, five winds, seven centres, three knots, and the locks and gestures where the map most directly shapes practice — then makes room for a parallel map from Traditional Chinese Medicine, and closes by comparing how yoga and TCM each use the idea of five elements. Three maps in total, one body.
The five koshas — yoga's layered self
YogoLogo's Layered Self runs from the physical body inward through the senses, ego, and intellect to pure awareness at the centre. That's one map. The koshas are yoga's other map of the same layered being — five sheaths, each subtler than the last, wrapped around the same centre.
Kosha means sheath, or covering. There are five, from densest to subtlest: Annamaya, the food body; Pranamaya, the breath or energy body; Manomaya, the mental sheath; Vijnanamaya, the wisdom sheath; and Anandamaya, the bliss sheath, closest to the centre.
The traditional image is a set of nested coverings around a single light. The light is already there; practice is not building it but loosening the sheaths so the light comes through. Asana works primarily on the first two — the food body and the energy body — but every layer influences every other. A stiff hip can quiet the mind; a grieving mind can stiffen a hip.
The Layered Self in full — the layers and the practice — lives on the Layered Self; the koshas mapped interactively onto those layers live with Yoga Philosophy, beside their classical roots.
The three nadis — channels of energy
If prana is the animating current, nadis are the channels it runs through. The classical texts count tens of thousands. Three matter for practice.
- Ida — runs up the left side of the spine. Associated with the moon: cool, receptive, introspective, restorative. When ida is dominant, the left nostril breathes more freely.
- Pingala — runs up the right side. Associated with the sun: warm, active, outward-facing, energising. When pingala is dominant, the right nostril breathes more freely.
- Sushumna — the central channel, running up the spine itself. Associated with stillness and integration. The aim of much yogic practice is to balance ida and pingala enough that energy flows freely up sushumna.
The resonance with the autonomic nervous system is worth naming. Ida tracks closely with the parasympathetic — settling, digesting, restoring; pingala with the sympathetic — mobilising, alerting, doing. That nostril dominance shifts through the day, and with practice, is observable. The deeper claim — that consciously balancing the two channels is part of how meditation becomes possible — is yoga's, not science's. Resonance, not equivalence.
Nervous-system mechanics live on Physical Anatomy; the practice that balances ida and pingala — nadi shodhana — lives on Pranayama.
The five vayus — the winds of prana
If prana is the current and nadis are the channels, the vayus are the directions of flow. Vayu means wind. There are five, each governing a region of the body and a kind of movement.
- Prana vayu — chest and head; the inward-and-upward current. Governs inhalation and reception. (Note: prana names both the whole life-current and this specific upward wind; context tells you which.)
- Apana vayu — pelvis and lower abdomen; the downward-and-outward current. Governs exhalation, elimination, and release.
- Samana vayu — the navel region; the gathering, balancing current. Governs digestion in the broadest sense — taking in, breaking down, distributing.
- Udana vayu — throat and head; the upward current. Governs speech, expression, and the lift of attention.
- Vyana vayu — the whole body; the pervading current. Governs circulation and the coordination of everything else.
Most yogic practice works with the interplay of prana and apana: inhaling, the upward current gathers; exhaling, the downward current releases. The two meet in the navel, where samana lives — where digestion happens, of food, of breath, of experience. The vayus are why a long exhale settles the system and a deep inhale lifts it.
Breathwork that consciously directs the vayus lives on Pranayama.
The seven chakras — a brief reference
Chakra means wheel. The seven main chakras are points along the central channel where the subtle anatomy says energy concentrates and organises. They are the part of yoga's inner map most familiar to modern readers, and the part most easily turned into something they were never meant to be. This is a reference, not a practice page — what follows is the map, so the language is available when you meet it elsewhere.
From base to crown:
- Muladhara — root, base of the spine. Earth. Grounding, survival, belonging.
- Svadhisthana — sacral, lower abdomen. Water. Creativity, sensuality, flow.
- Manipura — solar plexus, navel. Fire. Will, confidence, transformation.
- Anahata — heart, centre of the chest. Air. Love, compassion, connection.
- Vishuddha — throat. Ether or space. Expression, truth, communication.
- Ajna — between the eyebrows. Light. Intuition, clarity, discernment.
- Sahasrara — crown of the head. Sometimes given a colour and an element, sometimes pointedly not — it represents what is beyond all of that.
A modern bridge — the endocrine mapping
A modern interpretation maps each chakra onto a gland of the endocrine system. The mapping is intuitive — based mostly on shared location — and a useful bridge if you're coming from a Western frame. It is not a classical claim, and it isn't established science. Held as a bridge, it's helpful; held as anatomy, it overreaches. The pairings most commonly given: Muladhara → adrenals; Svadhisthana → reproductive glands; Manipura → pancreas; Anahata → thymus; Vishuddha → thyroid; Ajna → pituitary; Sahasrara → pineal. The locations line up neatly; the functional claims are not testable in any rigorous way. Take it as a memory aid and a translation device, not a mechanism.
The three granthis — knots on the central channel
If the chakras are points where energy organises, the granthis are points where it gets stuck. Granthi means knot. There are three, each placed at a major transition along sushumna.
- Brahma granthi — the lower knot, at the level of muladhara and svadhisthana. The knot of material attachment: survival, security, sensual pleasure. Practice meets it when these things stop running the show.
- Vishnu granthi — the middle knot, at the level of manipura and anahata. The knot of emotional attachment: relationships, identity through others, preference and aversion. Practice meets it when affection becomes broader than its objects.
- Rudra granthi — the upper knot, at the level of ajna. The knot of egoic attachment: the subtlest one, the attachment to being a particular someone with particular insights. Practice meets it when individuality itself begins to feel like a costume.
The classical claim is that energy rising up sushumna cannot pass these points without the corresponding knot loosening. Each granthi marks a different layer of identification — with the body, with the emotions, with the self — that has to be seen through before practice can deepen further. This is why the next section matters: each of the three main bandhas is said to act on one of the three granthis.
Bandhas and mudras — where the inner map meets the body
This is where subtle anatomy becomes most directly practical. Bandhas are locks — deliberate engagements of specific muscular and structural gateways. Mudras are gestures — of the hands, the face, or the whole body — that direct attention and, in yogic language, prana.
The three main bandhas, and the knots they address:
- Mula bandha — root lock. A gentle lifting of the pelvic floor, specifically the perineal body. Said to seal the downward flow of apana so it meets the upward flow of prana, redirecting energy along sushumna. Acts on brahma granthi.
- Uddiyana bandha — upward-flying lock. A drawing of the lower abdomen back and up under the ribcage, on empty lungs. Said to lift prana up the central channel. Acts on vishnu granthi.
- Jalandhara bandha — throat lock. A gentle drawing of the chin toward the chest. Said to contain prana in the upper body during breath retention. Acts on rudra granthi.
Practised together during certain breath retentions, the three are called maha bandha — the great lock. Mudras are subtler — small physical configurations said to act as valves and switches for attention and energy; the simplest is chin mudra, thumb and index fingertip touching, the rest extended, where the thumb represents pure awareness and the index finger the individual self, their meeting the union the whole practice points at.
The same caveat applies. The structures are real and the mechanical engagement is real; the energetic account is yoga's language for what practice feels like when these locks are used skilfully.
The full practical treatment — how to engage each lock — lives on Bandhas & Mudras, under Pranayama.
Meridians — a parallel map from Chinese medicine
Yoga isn't the only tradition that built a map of the body from the inside. Several thousand miles east and over a comparable span of centuries, Chinese medicine developed its own — different vocabulary, different organising principles, recognisably looking at the same territory. The names rhyme:
- What yoga calls prana, TCM calls qi — the animating current of a living body.
- What yoga calls nadis, TCM calls meridians — the channels that current flows through.
- What yoga calls the balance of ida and pingala, TCM calls the balance of yin and yang — the receptive and active poles. They aren't the same concept, but they're cousins.
TCM counts twelve principal meridians, each tied to an organ system, and two extraordinary vessels running up the central axis — roughly where sushumna runs. The resonance is real; the frameworks are not interchangeable. Treat the overlap as resonance, not equivalence.
Yin yoga: the practical bridge. One modern style of yoga is built directly on the meridian map. Yin yoga, developed by Paul Grilley and Sarah Powers, holds postures for long periods at moderate intensity, working the connective tissue and the meridians that run through it — the place where most Western practitioners first meet TCM's vocabulary inside yoga. → Its full treatment lives on Yin Yoga; the tradition itself has its own room on Traditional Chinese Medicine.
Five elements, two traditions
Both yoga and TCM organise their inner maps around five elements. The numbers match; the vocabulary does not; and the two are doing different work with the idea.
Yoga's five elements (also Ayurveda's). Pancha maha bhutas — the five great elements: ether (or space), air, fire, water, earth. Read as the building blocks of matter and experience, running from subtlest (ether) to densest (earth). The senses correspond to them — hearing to ether, touch to air, sight to fire, taste to water, smell to earth — and Ayurveda combines them in pairs to form the three doshas: vata (ether + air), pitta (fire + water), kapha (earth + water). The elements answer the question: what is this made of?
TCM's five elements. Wood, fire, earth, metal, water — no ether, no air. The TCM five are read as phases of transformation: wood rising, fire peaking, earth settling, metal contracting, water resting. Each phase generates the next and controls another across the cycle. The elements answer a different question: what phase is this in?
So the rhyme is real and the difference is real. Yoga is mapping substance; TCM is mapping process. You can hold both; they don't compete.
The body as a hand — a teaching diagram
One traditional teaching uses the hand itself as a map of the five elements. The lineage YogoLogo follows, as taught by Santosh (Yogadarshanam), maps the fingers this way: thumb — fire (solar plexus, manipura); index — air (heart, anahata); middle — ether (throat, vishuddha); ring — earth (root, muladhara); little — water (sacral, svadhisthana). Each finger ties to a chakra carrying the same element, so the hand becomes a portable diagram of the inner anatomy — and the logic behind hand mudras: bringing two fingers together is bringing two elements into contact.
A note on a discrepancy: Vasant Lad gives a different finger-element mapping in Ayurveda: The Science of Self-Healing — the same five elements, ordered differently, in a diagram organised around pulse diagnosis rather than chakra correspondence. The foundational texts don't fix a specific mapping; it's a lineage-level detail where teaching traditions diverge. YogoLogo follows the yoga lineage's version above because it integrates with the chakra map. Lad's is worth knowing, especially if you read his book.
Closing
Three maps of the same body. The outer one — bone, muscle, nerve, breath mechanics — is what Western medicine sees. The inner one — sheaths, channels, winds, centres, knots, locks — is what yoga sees, and what practice begins to feel like from inside. The third — meridians and qi — is TCM's, met most directly through yin yoga. Alongside all three, Ayurveda's reading of the body — the same five elements, organised into doshas — sits as a companion tradition.
No map replaces the others. The practical use of having more than one is this: when something happens on the mat that one vocabulary can't quite name — a release that isn't muscular, a settling that isn't a stretch — another map gives you language for it without asking you to abandon what you already know.
Sources
- Bihar School of Yoga — Asana, Pranayama, Mudra, Bandha; Prana and Pranayama; Moola Bandha — The Master Key (primary for koshas, nadis, vayus, chakras, granthis, bandhas)
- B.K.S. Iyengar — Light on Pranayama; Light on Yoga
- Leslie Kaminoff — Yoga Anatomy
- Vasant Lad — Ayurveda: The Science of Self-Healing
- Santosh (Yogadarshanam) — the yoga-lineage finger-element mapping
- Bernie Clark — The Complete Guide to Yin Yoga