Tantra recognizes seven energy centers in the human body. These are known as 'chakras'. Chakra means "what revolves" and hence signifies a wheel. In a physical sense the chakras are visualized as lotuses, composed of different number of petals. Each chakra governs a certain sense organ, and has its own presiding deity.
The seven chakras are:
Muladhara Chakra: Muladhara means "root foundation", and is hence also known as the root chakra. It is located at the base of the spine. This chakra has four petals and rules the organ of smell, the nose. Its presiding deity is Brahma.
Svadhishthana Chakra: In Sanskrit, Svadhishthana means self-abode. It is situated in the spine in the region just above the genitals, and is made up of six petals. This chakra governs the principle of taste, and its presiding deity is Lord Vishnu.
Manipura Chakra: Manipura means "the city of gems", and this chakra is thought to be radiant like a city of jewels. It is also called the 'navel' chakra since it is located behind the navel. It is made up of ten petals, and its presiding deity is Rudra. The Manipura chakra rules over the sense organ of sight, the eyes.
Anahata Chakra: Anahata means "unstuck sound", and it is from this chakra that the inner sounds or natural music of the body is said to arise. It is made up of twelve petals and is located along the spine at the level of the heart. Its presiding deity is believed to be Isha. It governs the organ of touch, the skin.
Vishuddha Chakra: Vishuddha means "very pure", and as such this center is believed to very subtle. It is made up of sixteen petals, and the presiding deity is Ardhanarishvara. This chakra governs the organ of sound, the ears, and is located in the throat.
Ajna Chakra: Ajna means command, and this chakra is called the center of command as it is from here that the other chakras are guided. It is often called the Third Eye, and is located between the eyebrows. And its presiding deity is Paramashiva. It rules over the mind as a sense organ.
Sahasra Padma Chakra: Sahasra in Sanskrit means thousand, and padma means lotus, this chakra hence is also known as "the thousand petalled lotus." It is located above the crown of the head. It is the meeting place of the Kundalini Shakti with Shiva. It governs the voluntary nervous system, and is said to be the seat of pure consciousness or ultimate bliss.