The Heaviest Organ in the Human Body

The liver is the heaviest organ in the human body. Its average weight is between 1.4 to 1.6 kilograms or 3.1 to 3.5 pounds. It is also the largest internal organ and the largest gland in the human body.

Liver

The Smallest Organ in the Human Body

The smallest organ in the human body is believed to be the pineal gland. It is an endocrine gland found within the brain. Its normal size is comparable to the size of a pea (about 8 millimeters only). The pineal gland is also known as epiphysis cerebri, epiphysis or pineal body.

Pineal Gland

The Most Complex Organ in the Human Body

The most complex organ in the human body is obviously, the brain. The brain is the control system of the central nervous system (CNS) which is responsible for behavior. It produces our every thought, action, feeling, memory and experience of the world. Approximately one hundred billion nerve cells or neurons with complex patterns of connectivity compose the brain.

Brain