A mudra is a symbolic or ritual gesture or pose in Hinduism, Jainism and Buddhism. While some mudras involve the entire body, most are performed with the hands and fingers. As well as being spiritual gestures employed in the iconography and spiritual practice of Indian religions, mudras have meaning in many forms of Indian dance, and yoga. The range of mudras used in each field differs, but with some overlap. In addition, many of the Buddhist mudras are used outside South Asia, and have developed different local forms elsewhere. In hatha yoga, mudras are used in conjunction with pranayama , generally while in a seated posture, to stimulate different parts of the body involved with breathing and to affect the flow of prana. It is also associated with bindu, bodhicitta, amrita, and consciousness in the body. Unlike older tantric mudras, hatha yogic mudras are generally internal contractions, involving the pelvic floor, diaphragm, throat, eyes, tongue, anus, genitals, abdomen, and other parts of the body. Examples of this diversity of mudras are Mula Bandha, Mahamudra, Viparita Karani, Khecarī mudrā, and Vajroli mudra. These expanded in number from three in the Amritasiddhi, to 25 in the Gheranda Samhita, with a classical set of ten arising in the Hatha Yoga Pradipika. Mudra is used in the iconography of Hindu and Buddhist art of the Indian subcontinent and described in the scriptures, such as the Nātyaśāstra, which lists 24 asaṁyuta and 13 saṁyuta mudras. Mudra positions are usually formed by both the hand and the fingers. Along with āsanas , they are employed statically in meditation and dynamically in the Nāṭya practice of Hinduism. Hindu and Buddhist iconography share some mudras. In some regions, for example in Laos and Thailand, these are distinct but share related iconographic conventions. According to Jamgön Kongtrül in his commentary on the Hevajra Tantra, the ornaments of wrathful deities and witches made of human bones are also known as mudra "seals".