The Human Brain: An "Unsolved Mystery"??..

Image credits

Of all the marvelous things on the earth, none is more astounding than the "human brain". For example, every second, "some 100 million bits of information pour into brain from the various senses"..

According to Dr. Irving S. Bengelsdorf, a science editor; "anyone who speaks of a 'computer' as an 'electronic brain' has never seen a brain"..

credit

The "Human Miracle"..yeah.!!..i call it that or the human brain, has the ability to scan messages at intervals of seconds without errors or mistakes..

Its "supernatural" nature and how it carries out this functions almost still remains remains a "mystery"??..

The human brain is the "command center of the central nervous system". It receives input from the sensory organs through the nerve cells and sends output to the muscles..

The human miracle

image credit

The human brain has the same basic structure as other mammal brains, but is larger in relation to body size than any other brains.

Interestingly, one may ask this question; HOW CAN THE HUMAN BRAIN COPE WITH OVER 100MILLION MESSAGES POURING INTO IT EVERY SECOND??..

Two factors are involved here, to enable the brain achieve this swiftly:

Firstly, in the brain stem, there is a network of nerves; equivalent to the size of your little fingers. This network is called the "recticular formation".

Image sources

It acts as a kind of traffic control center, monitoring the millions of messages coming into the brain, sifting out the trivial and selecting the essentials for attention by the cerebral cortex..

Each second, this little network of nerves permits only a few hundred, at most, to enter the conscious mind.

Secondly, a further pinpointing of our attention seems to come about by waves that sweeps the brain "8 to 12" times per second..

These waves cause periods of high sensitivity, during which the brain notes the stronger signals and acts upon it.wow..interesting isn't?

The most fascinating part, is that by means of these waves; "the brain scans itself about every tenth of a second to focus on the essentials"..

Therefore, "an amazing flurry of activity is going on in our heads every second!"..

HOW DOES THE HUMAN MIRACLE DEVELOP???..

image source

The "human brain" which is something to wonder at, begins in the womb.

Three weeks after conception, the brain cells start forming. They grow in spurts, at a time up to 250,000 cells in a minute.

After birth, the brain continues growing and developing its network of connections.

The "gulf" separating the human brain from that of any animal then manifest itself quickly.

"The brain of the human infant, unlike that of any other animal, triples in size during its first year", states the book The Universe Within..

Subsequently, in time; about 100 billion nerve cells, called "neurons", as well as other types of cell are packed into a human brain, although it makes up to only two percent (2%) of the body's weight.

The key brain cells; "the neurons", do not actually touch or coincide with one another. They are separated by "Synapses",(tiny spaces less than one millionth of an inch across).

These gaps are bridged by chemicals called neurotransmitters, 30 of which are known, but the brain may possess many more..

credit

These chemical signals are received at one end of the neuron by a maze of tiny filaments called "dendrites".

The signals are then transmitted at the end of the neuron by a nerve fibre called an "axon".

In the neurons, the signals are "electrical" but across the gaps, they are "chemical". Thus, the transmission of the nerve signals is "electro-chemical" in nature..

image source

Each impulse is of the same strength, but the intensity of the signal depends upon the frequency of the impulses, which may be as high as one thousand per second..

The vast numbers of microscopic nerves fibres making these connections within the brain are often referred to as its "wiring".

They are precisely placed within a maze of staggering complexity; but how they are placed in the exact spots called for by the "wiring diagrams" remains a mystery??..

credit

Parts of the Human Brain

image sources

The human brain consists basically of the following parts, namely;
The cerebrum, Hypothalamus, Pituitary gland, Pons, Corpus Callosum, Thalamus, Mid brain, Medulla Oblongata, Ventricles, Cerebellum and the Brain stem..

Anatomy, Design and Functions of the Parts of the Human Brain

A diagram of the cross section of the human brain

image credit

According to "neuroanatomy", the "cerebrum" is the uppermost part of the brain, which is subdivided into two cerebral hemispheres..

In humans, it is the largest part of the brain and is described as the seat of motor and it also performs other sensory functions. It is responsible for higher mental functions such as; consciousness, reasoning, emotions, thoughts and memory.

Below the cerebrum, lies the "brain stem", and behind, sits the "cerebellum".

The outermost later of the cerebrum, is the "cerebral cortex", which comprises of four(4) lobes, namely; "the frontal lobe, the Parietal lobe, the Temporal lobe and the Occipital lobe.

Image source

The human brain, like other vertebrate brains, consists of three sections, namely; the "forebrain, midbrain and hindbrain". Each of which contains cavities full of fluids known as "Ventricles".

The forebrain develops into the cerebrum and underlying structures; the midbrain becomes part of the brain stem, and the hindbrain gives rise to regions of the brain stem and the cerebellum.

The "Cerebral cortex" is a large piece in human brains, and is described as the seat of complex thought.

Close to the back of the skull, we have the "Occipital lobe" that helps in "visualization or visual processing"..

The "Temporal lobes" comprises of : the "Hippocampus" and "Amagydala", which processes "sound" and "language". These part also play important role in "memory" and "emotion" respectively..

The "Parietal lobes" is vital for space and navigation. It also joins input to the brain from different senses.

The "Thalamus" and "Hypothalamus " lies in between the cerebrum and the brain stem. The hypothalamus connects the nervous system to the endocrine system where hormones are produced through the pituitary gland.

The thalamus links sensory and motor signals to the cortex and is also involved in regulating consciousness, alertness and sleep.

The "Cerebellum" lies under the cerebrum and has a vital function in motor control. It plays a role in coordination, balance and also helps in recognition.

The human brain is subdivided divided into two hemispheres; the left and right, connected by a bundle of nerve fibers called the "Corpus callosum".

The "hemispheres" are strongly, though not entirely, symmetrical. The right brain controls all the muscles on the left-hand side of the body; and the left brain controls the right side.

One hemisphere may be slightly dominant, as with left- or right-handedness. The left brain is said to contain regions involved in speech and language and the right brain is responsible for space, visual processing and artistic skills.

Lastly, the "Brain stem"; which is the carrier of the other parts, connects the brain to the spinal cord and comprises of the; "Medulla Oblongata, Pins and Midbrain".

The basic functions of the brain stem are: supplying some of the cranial nerves to the face and head, linking information between the brain and the body and also performing critical functions in controlling the heart breathing and consciousness.

functions of the parts of the human brain

image source

Some fascinating facts about the human brain

• The human brain is the largest brain of all vertebrates relative to body size. It weighs about 3.3 lbs. (1.5 kilograms).

• The brain makes up about 2 percent (2%) of a human's body weight.

• The cerebrum makes up 85 percent (85%) of the brain's weight.

• It contains about 86 billion nerve cells (neurons) — the "gray matter".

credit

• It contains billions of nerve fibers (axons and dendrites) — the "white matter". These neurons are connected by trillions of connections, or synapses..

image source

According to the science writer, Morton Hunt; "our active memories hold several billion times more information than a large contemporary research computer"..

Nevertheless, I think, the "human brain" is the most marvelous and mysterious object in the whole universe..hope you enjoyed it..

References

1. Color Atlas of Anatomy by Rohen, Yokochi and Lutjen-Drecoll.
2. The book; "The Universe Within"
3. http://www.livescience.com
4. http://wikipedia.com

• Samuel Isongs (@profsam)