Chakras are believed to be part of the subtle body, not the physical body, and as such, are the meeting points of the subtle (non-physical) energy channels called nadi.
Sahasrara Ajna Vishuddha Anahata Manipura Svadhishthana Muladhara Bindu There are believed to be seven major chakras, which are arranged vertically along the axial channel (sushumna nadi). David Gordon White traces the modern popularity of the seven chakra system to Arthur Avalon's The Serpent Power, which was Avalon's translation of a late work, the Sat-Cakra-Nirupana. Below is a description of the seven chakras, with various associations. Each of these chakras also has its elemental deity (Vasu), demigod of its material element. From the top down, they are thought to be: Sahasrara Sahasrara (Sanskrit: सहस्रार, IAST: Sahasrāra, English: "thousand-petaled") or crown chakra is generally considered to be the state of pure consciousness, within which there is neither object nor subject. When the Kundalini energy rises to this point, it unites with the male Shiva energy, and a state of liberating samadhi is attained. Symbolized by a lotus with one thousand multi-coloured petals, it is located either at the crown of the head, or above the crown of the head. Sahasrara is represented by the colour white and it involves such issues as inner wisdom and the death of the body. Its role may be envisioned somewhat similarly to that of the pituitary gland, which secretes hormones to communicate to the rest of the endocrine system and also connects to the central nervous system via the hypothalamus. According to Gary Osborn, the thalamus is thought to have a key role in the physical basis of consciousness and is the 'Bridal Chamber' mentioned in the Gnostic scriptures. Sahasrara's inner aspect deals with the release of karma, physical action with meditation, mental action with universal consciousness and unity, and emotional action with "beingness." Corresponding deity for material element of this state is Dhruva. Ajna Ajna (Sanskrit: आज्ञा, IAST: Ājñā, English: "command") or third-eye chakra is symbolised by a lotus with two petals, and corresponds to the colours violet, indigo or deep blue, though it is traditionally described as white. It is at this point that the two side nadi Ida (yoga) and Pingala are said to terminate and merge with the central channel Sushumna, signifying the end of duality, the characteristic of being dual (e.g. light and dark, or male and female). The seed syllable for this chakra is the syllable OM, and the presiding deity is Ardhanarishvara, who is a half male, half female Shiva/Shakti. The Shakti goddess of Ajna is called Hakini. Ajna (along with Bindu), is known as the third eye chakra and is linked to the pineal gland which may inform a model of its envisioning. The pineal gland is a light sensitive gland that produces the hormone melatonin which regulates sleep and waking up, and is also postulated to be the production site of the psychedelic dimethyltryptamine, the only known hallucinogen endogenous to the human body. Ajna's key issues involve balancing the higher and lower selves and trusting inner guidance. Ajna's inner aspect relates to the access of intuition. Mentally, Ajna deals with visual consciousness. Emotionally, Ajna deals with clarity on an intuitive level. Vishuddha Vishuddha (Sanskrit: विशुद्ध, IAST: Viśuddha, English: "especially pure"), or Vishuddhi, or throat chakra is depicted as a silver crescent within a white circle, with 16 light or pale blue, or turquoise petals. The seed mantra is Ham, and the residing deity is Panchavaktra shiva, with 5 heads and 4 arms, and the Shakti is Shakini. Vishuddha may be understood as relating to communication and growth through expression. This chakra is paralleled to the thyroid, a gland that is also in the throat and which produces thyroid hormone, responsible for growth and maturation. Physically, Vishuddha governs communication, emotionally it governs independence, mentally it governs fluent thought, and spiritually, it governs a sense of security. In Tibetan buddhism, this chakra is red, with 16 upward pointing petals. It plays an important role in Dream Yoga, the art of lucid dreaming. Corresponding deity for material element of this chakra is Dyaus. Anahata Anahata (Sanskrit: अनाहत, IAST: Anāhata, English: "unstruck") or heart chakra is symbolised by a circular flower with twelve green petals called the heartmind. Within it is a yantra of two intersecting triangles, forming a hexagram, symbolising a union of the male and female. The seed mantra is Yam, the presiding deity is Ishana Rudra Shiva, and the Shakti is Kakini. Anahata is related to the thymus, located in the chest. The thymus is an element of the immune system as well as being part of the endocrine system. It is the site of maturation of the T cells responsible for fending off disease and may be adversely affected by stress. Anahata is related to the colours green or pink. Key issues involving Anahata involve complex emotions, compassion, tenderness, unconditional love, equilibrium, rejection and well-being. Physically Anahata governs circulation, emotionally it governs unconditional love for the self and others, mentally it governs passion, and spiritually it governs devotion. Manipura Manipura (Sanskrit: मणिपूर, IAST: Maṇipūra, English: "jewel city") or solar plexus/navel chakra is symbolised by a downward pointing triangle with ten petals, along with the colour yellow. The seed syllable is Ram, and the presiding deity is Braddha Rudra, with Lakini as the Shakti. Manipura is related to the metabolic and digestive systems. Manipura is believed to correspond to Islets of Langerhans, which are groups of cells in the pancreas, as well as the outer adrenal glands and the adrenal cortex. These play a valuable role in digestion, the conversion of food matter into energy for the body. The colour that corresponds to Manipura is yellow. Key issues governed by Manipura are issues of personal power, fear, anxiety, opinion-formation, introversion, and transition from simple or base emotions to complex. Physically, Manipura governs digestion, mentally it governs personal power, emotionally it governs expansiveness, and spiritually, all matters of growth. Corresponding deity for material element of this chakra is Agni. Svadhishthana Svadhishthana (Sanskrit: स्वाधिष्ठान, IAST: Svādhiṣṭhāna, English: "one's own base") or sacral chakra is symbolised by a white lotus within which is a crescent moon, with six vermilion, or orange petals. The seed mantra is Vam, and the presiding deity is Brahma, with the Shakti being Rakini (or Chakini). The animal associated is the crocodile of Varuna. This chakra is located in the sacrum and is considered to correspond to the testes or the ovaries that produce the various sex hormones involved in the reproductive cycle. Svadhishthana is also considered to be related to, more generally, the genitourinary system and the adrenals. The key issues involving Svadhishthana are relationships, violence, addictions, basic emotional needs, and pleasure. Physically, Svadhishthana governs reproduction, mentally it governs creativity, emotionally it governs joy, and spiritually it governs enthusiasm. Muladhara Muladhara (Sanskrit: मूलाधार, IAST: Mūlādhāra, English: "root support") or root chakra is symbolised by a lotus with four petals and the colour red. This centre is located at the base of the spine in the coccygeal region. It is said to relate to the gonads and the adrenal medulla, responsible for the fight-or-flight response when survival is under threat. The seed syllable is LAM. Muladhara is related to instinct, security, survival and also to basic human potentiality. Physically, Muladhara governs sexuality, mentally it governs stability, emotionally it governs sensuality, and spiritually it governs a sense of security. Muladhara also has a relation to the sense of smell. This chakra is where the three main nadi separate and begin their upward movement. Dormant Kundalini rests here, wrapped three and a half times around the black Svayambhu linga, the lowest of three obstructions to her full rising (also known as knots or granthis).It is the seat of the red bindu, the female drop (which in Tibetan vajrayana is located at the navel chakra).[clarification needed] The seed syllable is Lam (pronounced lum), the deity is Ganesh, and the Shakti is Dakini.The associated animal is the elephant.