Brain

The brain is the body's main control center and the most complex organ of the nervous system. Protected by the skull and surrounded by cerebrospinal fluid, it contains about 86 billion neurons, specialized nerve cells that communicate through electrical and chemical signals.

These neurons form vast networks that process information from the senses, control movement, regulate breathing and heartbeat, and make learning, memory, language, emotions and decision-making possible. The brain also works continuously without conscious effort, coordinating many automatic functions that keep the body alive while adapting to changes inside and outside the body.

Although it represents only about 2% of an adult's body weight, the brain uses around 20% of the body's oxygen and energy because its cells are constantly active. It is divided into several regions with different roles, including the cerebrum, which is involved in thought, perception and voluntary movement, the cerebellum, which helps maintain balance and coordinate precise movements, and the brainstem, which controls essential functions such as breathing, heart rate and wakefulness.

The brain remains capable of changing throughout life by forming and strengthening connections between neurons, a property known as neuroplasticity. Healthy sleep, regular physical activity, mental stimulation and a balanced diet all contribute to maintaining normal brain function.