what is the brain

The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger, and every process that regulates the body. It is the most complex part of the human body, weighing about three pounds in the average adult. The brain is composed of the cerebrum, brainstem, and cerebellum, with the cerebrum being the largest part of the brain and performing higher functions like interpreting touch, vision, and hearing. The brain is responsible for controlling thinking, behavior, movement, and more, and it receives, processes, and interprets sensory information. It has three main parts: the cerebrum, cerebellum, and brainstem, each with its own special responsibilities. The brain is nourished by a rich network of blood vessels and contains about 100 billion nerve cells, with branches connecting the nerve cells at more than 100 trillion points.