New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Human brain

The human brain is the most complex organ in the body and the control center of the nervous system. Weighing about three pounds and composed of approximately 86 billion neurons, it governs every aspect of thought, emotion, behavior, and bodily function. Protected by the skull and suspended in cerebrospinal fluid, the brain processes sensory information, coordinates movement, regulates internal systems, and enables learning, memory, language, and consciousness.

The brain is divided into several major regions, each with specialized roles. The cerebrum, the largest part, is responsible for higher cognitive functions like reasoning, problem-solving, and voluntary movement. It is divided into left and right hemispheres and further into lobes that handle vision, touch, hearing, and decision-making. The cerebellum, located beneath the cerebrum, helps coordinate balance and precise motor control. The brainstem connects the brain to the spinal cord and regulates vital functions such as breathing, heart rate, and sleep.

The brain communicates through a vast network of neurons, which transmit electrical and chemical signals via synapses. Supporting these neurons are glial cells, which provide structural support, nutrition, and protection. This intricate system allows the brain to integrate information from the environment, make decisions, and generate responses in real time.

The human brain is also remarkably adaptable. Through a process called neuroplasticity, it can reorganize itself by forming new neural connections in response to learning, injury, or experience. This adaptability is key to development, recovery, and cognitive flexibility throughout life.

Understanding the brain remains one of science’s greatest challenges. Advances in neuroscience and neuroimaging continue to uncover how the brain functions in health and disease, offering insights into conditions such as Alzheimer’s, Parkinson’s, stroke, epilepsy, and mental illness. As research progresses, the human brain remains both a marvel of biology and a frontier of scientific discovery.

Related Stories
 


Health & Medicine News

August 26, 2026

Moderate calorie restriction lowered an immune protein called C3 that appears to help drive chronic inflammation as the body ages. Blocking the same protein reduced age related inflammation in mice, ...
Britain’s postwar sugar rationing created a rare natural experiment that let researchers examine how early sugar exposure might affect health decades later. People who experienced more rationing during their first 1,000 days had lower rates of ...
A compound found in turmeric may help protect blood vessels from some of the damage caused by Type 1 diabetes. In rats, curcumin reduced inflammation, improved cellular signaling, and restored vascular health to levels resembling those of ...
A wavelength of light largely missing from indoor LEDs may play an important role in protecting developing eyes from nearsightedness. Researchers found that indigo light completely prevented myopia in tree shrews, whose eyes share important ...
Early-life stress may physically alter how DNA is packaged in the brain, leaving stress-related genes primed to activate more easily years later. In mice, researchers were able to block this effect, preventing the heightened anxiety and stress ...
A low-carb diet may raise LDL cholesterol much more sharply in people who are genetically predisposed to high cholesterol, particularly when they consume lots of saturated fat. The findings could help explain why people following seemingly similar ...
Older adults who received the Shingrix shingles vaccine were 24% less likely to be diagnosed with dementia over four years in a study of more than 500,000 people. Researchers estimate the difference could amount to roughly one dementia case ...
Researchers have found a way to supercharge natural killer cells, powerful immune cells that can attack cancer, so they can penetrate solid tumors and keep fighting once inside. In mice, these ...
A major study found that adults with depression show disrupted production of new neurons in the hippocampus, potentially weakening the brain’s ability to separate new experiences from painful memories. The researchers also identified broad ...
People who reach 110 and beyond appear to have unusually large numbers of rare immune cells capable of killing abnormal cells. These CD4 cytotoxic T cells became more common with age and often expanded into large groups of nearly identical cells, ...
Common medications may reshape the gut microbiome long after the last dose is taken. In a study of more than 2,500 people, researchers found lasting microbial changes linked not only to antibiotics, but also to antidepressants, beta-blockers, ...
Backyard bird feeders could become unexpected hotspots for H5N1 as Australia’s bird flu outbreak spreads, bringing species together in ways that rarely occur naturally. Experts say stopping feeding is safest, while smaller amounts of food, no ...

Latest Headlines

updated 12:56 pm ET