Your Brain - General Features
The Human Cortex
The most striking feature of the human brain is seen in the cortex. This is the folded, hemispherical structure which constitutes the bulk of the visible brain.
It is not present in reptiles.
The cortex is relatively recent. It is perhaps one hundred thousand years old and is the part of the brain most closely associated with our ability to form complex representations of the external world, to reason logically and to use language.
It is much more dominant in humans than in any other species.
Regions of the cortex control vision, our auditory senses, and voluntary movement and touch sensations. It is also crucial for long term memory.
Neurons and Networks
The central nervous system is composed of something like one hundred billion nerve cells or neurons.
Each nerve cell or neuron possesses a single axon along which it can pass electrical signals to other neurons. Incoming signals are carried by a neuron's dendrites which form a tree-like structure around the neuron.