The Brain (By Marcos and Alex)

The brain is the main organ of the nervous system, and the organ who difference us more, from the rest of the animals of the planet.


The brain is the organ that is responsible for the sense, thought, memory and body control. The human brain is a relatively small, weighing about 1.5 kilograms and takes about 2 percent of body weight. It is surrounded by a skull for a physical protection.
And it is formed by 30.000 millions of neurons formed a grey-pink tissue.

• The brain is divided into two hemispheres (left and right), each consisting of four lobes (frontal, parietal, occipital and temporal). The outer layer of the brain called the cerebral cortex or "gray matter". It covers the deep nuclei located in the cerebral hemisphere called "white matter".

• Cerebellum: responsible for psychomotor function, the cerebellum coordinates the inner ear sensory input and muscle for adequate control of the position and movement.

• Brainstem: at the base of the brain, forms the link between the cerebral cortex, white matter and spinal cord. Involved in the control of breathing, sleep and circulation.

• Thalamus and hypothalamus: The thalamus has a wide range of connections with the cortex and many other parts of the brain, as the basal ganglia, hypothalamus and brain stem. You can feel the pain but does not locate precisely. The hypothalamus has several important functions, including appetite control, sleep patterns, sexual behavior and response to anxiety.´

• Basal ganglia:The caudate nucleus, putamen and globus pallidus and basal ganglia are involved in controlling movement. These highly specialized groups of cells / nuclei are located in the white matter behind the cerebral cortex.

The brain is billateral, have two parts exactly alike, but the left part controlls the right part of the body or vice versa.

The first the first indication of the existence of the first brains was in the Cambrian explosion, from this, the brains evolved a lot, and we still fight for complain it.