biological clock — Your biological clock is your body's way of registering time. It does not rely on events such as day or night, but on factors such as your habits, your age, and chemical changes taking place in your body.
biorhythm — a cyclically recurring pattern of physiological states in an organism or organ, such as alpha rhythm or circadian rhythm; believed by some to affect physical and mental states and behaviour
wheel of life — the symbol of the cycle of birth, death, and reincarnation.
