Based on the diameter of the cell, the largest cell in the body is the oocyte, or egg. However if based on the length of the cell’s synapses, it is the nerve cell. 1. The oocyte is the female reproductive cell, which has a diameter of about 200μm and is spherical in shape. After a woman is born, the number of oocytes is fixed, and in most cases, only one oocyte matures and is released each menstrual cycle. 2. Nerve cells are the cells that conduct and exchange information, and they are the cells with the greatest length in the human body. For example, the motor cells in the anterior horn of the spinal cord can transmit information about motor commands from the brain from the spinal cord to the end of the toes. There are many kinds of cells in the human body with different forms, which play different physiological functions in the organism and work together to maintain the normal functioning of the human body.