Brain

The brain is one of the largest, most vital organs in the human body; without the brain, life would not be possible.
The human brain is comprised of aproxiamtly 100 billion nerve cells that communicate with one another by means of trillions of connections called synapses.
The brain recieves the infomation input (stimuli) by means of the sensory organs and utilises its processig capacity to mediate an appropriate reponse(s).

The brain is located within the skull (the cranium) for protection, and is surrounded by a group of membranes called the meninges consisting of the dura mater, the arachnoid and the pia mater. It is also surrounded by Cerebrospinal fluid (CSF) which provides more protection, cushioning the brains cortex by filling the space between the arachanoid membrane and the pia mater.

The brain can be divided into four main components, the first being the cortex, the outermost layer of brain cells (neurons), which are involved in thinking and in voluntary movement.
The basal ganglia are a cluster of structures found within the centre most region of the brain which facilitate the coordination of electrical impulses within different regions of the brain.
The cerebellum is found at the base of the brain and is associated with coordination in space and balance, with the brainstem being located between the spinal cord and the remainder of the brain and controlling our most basic functions such as breathing, heart rate regulation and blood pressure.