Which actually is as big as two fists!

Nov 3, 2007 10:06 GMT  ·  By

1. The brain cortex, with a thickness of just a few millimeters, contains 75 % of the brain cells, their number being between 10 to 100 billion. This area harbors our "mind", thoughts, personality, records, feelings and consciousness.

The link between the two hemispheres of the cortex is done by the corpus callosum, located under the cortex. In women, corpus callosum is more developed than in men.

Most of the information reaching the cortex passes through thalamus ("the inner room"). Nearby is the hypothalamus ("lower inner room") which controls body temperature and blood pressure. The hypothalamus has a little tab called hypophysis (pituitary gland), which controls most hormones of the body. Cerebellum controls all the information linked to movement and balance (like when we ride a bike). The rachidian bulb, at the joint with the spine, controls breathing, blood circulation, heart rhythm and digestion.

2. The human brain is the size of two fists. If the cortex were plain and unfolded, the human brain would have been the size of a basketball ball.

3. How does the brain form sensations? For example, over 30 brain areas process information delivered by the eyes. In the visual cortex and a nearby area, the information are sorted, integrated and addressed. A third region detects shape and movement. A fourth area recognizes both shape and color, while a fifth actualizes continuously the maps realized for following the movement.

4. One crucial difference between a brain and a computer is that the brain functions on chemical, not electric, signals. A brain does not need to be programmed; it functions spontaneously. Some neurons can react to over 1,000 signals received from receptors or other neurons (and called synaptic). For example, in the smell sense (which is quite reduced in humans) 6 million neurons are involved, each one receiving about 10,000 signals from the surrounding neurons.

5. For each neuron in the brain, there are several auxiliary cells called glial. They keep the brain compact, act as electric isolation between neurons, fight infections and form a protective barrier.

6. What are memories? Hard to say. Scientists make the difference between declarative (facts) and procedural (habits and customs) memories.

Memories can be on very short term (up to 100 milliseconds), short term, working (active) memory that retains recent facts, and long term memory, which retains practiced verbal and motor skills. The long term memory has been linked to frontal cortex and information chosen for long term memory passes as electrical impulses through a brain area called hippocampus, which accomplishes a process of long term powering, which increases neurons' ability to transmit messages.

Another theory says that the brain's electrical rhythms are involved. The repeated oscillations (similar to a drum beats) contribute to the association between records and the moment when various brain cells are activated.

Various memories are believed to be kept in different brain parts, every concept storing memories in the brain part to which is associated. The amygdala, a nucleus at the base of the brain trunk, processes memories connected to fear. Basal glands are connected to habits and physical skills, while cerebellum is involved in conditional learning and reflexes.

7. The complex human speech has been linked to two brain areas. What we want to say is initiated in an area of the left cortex called "Wernicke zone". This communicates with "Broca zone", involved with grammatical rules. Impulses go from these areas to the muscles involved in speech. These zones are connected with the visual system (so we can read), auditory system (so we can hear what others say, understand and answer) and also have a memory bank for recalling valuable thoughts.

8. Connections between neurons are constantly changing, and if unused or unstimulated, they can disappear. That's why the brain needs constant intellectual stimulation and mind games.

Newborn babies are not blind, but they must develop the sight sense. First, they can focus only on the nearby objects. Than they start to see in 3-D when they make the difference between the images transmitted by the eyes. If one of the eyes is tapped in this period, the child won't be able to see well with it after that, as the entrance signal from the other eye controls the visual cortex of the brain.

Music too boosts child's speech and social behavior abilities. Children receiving supplementary music classes speak better and learned reading faster than other kids. Those playing instruments had better cooperation skills.

9. The right brain hemisphere is linked mostly to emotional functions and music feeling, while the left hemisphere is more analytical, linked to logical thinking and abilities.