Final answer:
The human brain, weighing about three pounds, features a complex structure with the cerebral cortex, neurons, and specialized regions like the forebrain, midbrain, and hindbrain that control a variety of functions from basic to advanced cognitive processes.
Step-by-step explanation:
The adult human brain is an incredibly complex organ, weighing about 1.5 kg (approximately three pounds) and occupying about 1.1 liters in volume. Its anatomy comprises numerous folds within the cerebral cortex to fit a larger surface area of gray matter within the limited space of the cranial cavity. The brain can be divided into three main parts: the forebrain, midbrain, and hindbrain, which are responsible for various functions ranging from higher cognitive processes to autonomic functions that occur without conscious thought.
Communication within the brain and the central nervous system is facilitated by specialized cells known as neurons, which can connect to thousands of other neurons via synapses. It's also notable that the brain's size is linked to the body size rather than intelligence and involves processes like blooming and synaptic pruning across different life stages to improve its efficiency.