The Human Brain -Only Science

The Brain

The brain is an amazing three-pound organ that controls all functions of the body, interprets information from the outside world, and organizes the essence of the mind and soul. A few of the many things governed by the brain are Intelligence, creativity, emotion, and memory. Protected within the skull, the brain is composed of the cerebrum, cerebellum, and brainstem. It is made up of more than 100 billion nerves that communicate in trillions of connections called synapses. 

The brain receives information through five senses: sight, smell, touch, taste, and hearing - often many at one time. It assembles the messages in so that it has meaning for us and can store that information in our memory. The brain controls our thoughts, memory, speech, movement of the arms and legs, and the function of many organs within our body.

The central nervous system-CNS is composed of the brain and spinal cord. The peripheral nervous system-PNS is composed of spinal nerves that branch from the spinal cord and cranial nerves that branch from the brain.

The largest part of the human brain is The cerebrum. The cerebral cortex is an outer layer of grey matter, which covers the core of the white matter. The cortex is split into the neocortex and the much smaller allocortex. The neocortex is made up of six neuronal layers, while the allocortex has three or four neuronal layers. Each hemisphere is conventionally divided into four lobes – the frontal, temporal, parietal, and occipital lobes. The frontal lobe is associated with executive functions including self-control, planning, reasoning, and abstract thought, while the occipital lobe is dedicated to vision. Within each lobe, cortical areas are associated with specific functions, such as the sensory, motor, and association regions. Although the left and right hemispheres are broadly similar in shape and function, some functions are associated with one side, such as language in the left and visual-spatial ability in the right. The hemispheres are connected by commissural nerve tracts, the largest being the corpus callosum.

Facts:

1. The human brain is the largest of all vertebrates in relation to body size.
2. It weighs about 3.3 pounds or 1.5 kilograms.
3. The average male has a brain volume of 1,274 cubic centimeters.
4. The average female brain has a volume of 1,131 cubic centimeters.
5. The brain makes up about 2% of the human body weight.
6. The cerebrum makes up 85% of the brain's weight.
7. It contains about 86 billion nerve cells (neurons).
8. It contains billions of nerve fibers (axons and dendrites).
9. These neurons are connected by trillions of connections or synapses.
10. About 75% of the brain is made up of water. This means that dehydration, even in small amounts, can have a negative effect on the brain functions.
11. The sperm whale's brain is the largest brain In all animals. It weighs about 20 pounds.
12. The human brain will grow three times its size in the first year of life. It continues to grow until you're about 18 years old.
13. It is a myth that humans only use 10 percent of the brain. We actually use all of it. We’re even using more than 10 percent when we sleep.

Source: Wikipedia