The organ that works 24 hours is the kidney although that is just one of the organs of the body that works 24 hours.
Other organs that work 24 hours include the heart and brain.
The heart is a pump that keeps blood moving around your body.
It works 24 hours a day to keep you alive. Each day, your heart beats about 100,000 times.
The smallest organ in the human body is the pineal gland which can be found near the center of the brain, in a groove between the hemispheres.
It's not an organ like those in the abdominal cavity.
The pineal gland is a small, pea-shaped gland in the brain.
The pineal glands function isn't fully understood although researchers do know that it produces and regulates some hormones, including melatonin.
Melatonin is best known for the role it plays in regulating sleep patterns.
Sleep patterns are also called circadian rhythms.
Hair is an accessory organ.
Hair comes from hair follicles which is a type of organ.
Hair is an accessory organ of the skin made of columns of tightly packed dead keratinocytes found in most regions of the body.
The accessory structures of the skin, including the hair, nails, sweat glands and sebaceous glands, play an important role in the skin's key functions.
Hair is made of a tough protein called keratin.
A hair follicle anchors each hair into the skin.
The hair bulb forms the base of the hair follicle.
In the hair bulb, living cells divide and grow to build the hair shaft.
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function.
In the hierarchy of life, an organ lies between tissue and an organ system.
Tissues are formed from same type cells to act together in a function.
The brain is also an organ and one of the most complex organs in the human body.
The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulates our body.
Together, the brain and spinal cord that extends from it make up the central nervous system, or CNS.