by Omar Salvador

Created on: November 18, 2011   Last Updated: November 21, 2011

The activities of all the organs and systems of the human body are controlled by a dominant organ - the brain. As the body's master organ, the human brain is the center of consciousness, emotion, learning, reason, and skill; it is likewise a repository of memories. The intricateness of the human brain and its power to direct influence over every process of the body make even the most advanced computer an

insignificancy when compared to it.

The human brain - that compact mass of puckered grey and white matter protected first and foremost by the skull - is one amazing electrical and chemical machine. Millions of  fragments of information are received, processed and sent out by this super machine every second, and this is true even during sleep. It does not, however, work alone; it counts on the body's sense organs for information from the outside world. The complexity of the structure of the human brain is such that to describe it, in detail, as an electrical and chemical machine is quite a task.

The brain structure, in a nutshell:

Among all the organs of the body, the brain is the one that is best protected. Weighing about 1400 grams (49 ounces), the brain is secured by 3 layers of protection, each one carefully arranged. The first layer is the hard, bony helmet known as the skull. The second layer consists of three strong fibrous membranes known as the meninges, which further envelop and protect the brain's delicate tissues. Lastly, a cushion of cerebrospinal fluid circulates between the middle (arachnoid mater) and inner (pia mater) meninges, buffering the brain, especially when the head is knocked from side to side or from back to front.

The human brain is made up of 3 main parts:

1. Cerebrum - interprets messages from the sense organs and controls such higher functions as the ability to speak, reason, and remember. This activity takes place largely in the cortex, the outer grey layer of the cerebrum.

2. Cerebellum - orchestrates balance and muscle coordination.

3. Brain stem - links the brain with the spinal cord and helps to regulate the vital functions of the body, including breathing, heartbeat, sneezing, coughing, swallowing, and blinking.

Several more crucial structures are located deep within the brain:

- Thalamus - relays sensory nerve impulses to the cerebral cortex.

- Hypothalamus - secretes the chemical corticoliberin, which helps to control the body's metabolism and to regulate appetite and sex drive.

- Pituitary gland - secretes different

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