The nervous system is split in to two major systems: The Central Nervous System and The Peripheral Nervous System.
The Central Nervous System consists of the brain and the spinal cord. The brain is divided into two symmetrical hemispheres: left (language & analytical thinking) and right (the artistic abilities of a person). The brain is then divided further into four lobes, the Frontal lobe, the Parietal lobe, Occipital lobe, Temporal lobe.
The frontal lobe is concerned with executing behaviour. This ranges from the control of individual muscles in the primary motor cortex to high level abstract planning about what to do.
The parietal lobe controls neurons that receive sensory information from the skin and tongue. The major sensory inputs from the skin touch, temperature, and pain relay through the thalamus to parietal lobe.
Occipital lobe processes visual input that is sent to the brain from the retinas. The retinas project onto the posterior pole of the occipital lobe, so that activity in different areas of V1 is related to whatever is in the image around your current point of gaze.
Temporal lobe combines auditory and visual information.
The brain contols the entire body, it sends and receives millions and millions of messages a day.
As stated above, different areas of the brain control different body functions.
Inside the brain lies the cerebral cortex, which is split in to two cerebral hemispheres. The nerve centres that control thought and voluntary action lie in these hemispheres. A broad band of fibres called the corpus callosum connect these two hemispheres together. Because nerve fibres cross each other at the base of the brain before travelling down the spinal chord, each hemisphere generally controls functions in the opposite side of the body. For example, a region in the right hemisphere manages movement of the left arm.
The brain is the most complex organ in the body. Much research has gone in to the capabilities of the brain in particular memory, reasoning, and creative thought; still much of the brain remains a total mystery.
The Brain Fact Sheet:
- The human brain is composed of about 100 billion neurons plus a trillion glial cells.
- We have more brain cells as a baby than we will ever have again.
- Lack of oxygen to the brain for 5-10 minutes results in permanent damage.
- Your brain keeps developing until your late 40’s.
- New brain connections are created every time you make a memory.
- Your brain uses 20% of the total oxygen in your body.
- When awake, the human brain produces enough electricity to power a small light bulb.
- 60% of your brain is fat.
- Half our brains can be removed by surgery with no apparent effect on personality of memory.