The Most Complex Machine
By Liana
Staff Writer
The human brain is the most complex machine in the world. We all have one--it sits in our heads and controls our thoughts and actions. It governs who we are, basically. But what exactly is the brain? How does it work, and what are the secrets behind this amazing blob inside our skulls?
The brain contains about one hundred billion nerve cells, called neurons. Collectively, the neurons are called grey matter. But, each neuron sends out long thin structures called axons and dendrites that let it connect to other neurons. The brain’s white matter is made up of these axons and dendrites. The brain also contains another type of cell, glial cells, which amplify brain signals and aid thought processing.
Great, the brain is made of cells. But how does it work? The neurons communicate with each other via releasing and receiving neurochemicals (e.g. glutamate, dopamine, etc.). Some of these chemicals simply pass an impulse signal from one neuron to another (they do this by crossing a synapse—a tiny gap—from one neuron to the other); other chemicals influence entire brain regions. The brain makes million of new connections every second, while losing other connections. This is what lets us remember things, form habits, and have a unique personality.
New technology has allowed us to learn more about the brain. This technology includes electroencephalograms (from the scalp it detects neurons’ electrochemical pulses), positron emission tomography (PET scan, monitors blood flow), and magnetic resonance imaging (MRI, images the actual brain).
These new technologies have helped people associate certain areas of the brain with certain functions. These are the main parts:
Cerebrum: The largest part of the brain is made up of two hemispheres. The right hemisphere generally controls creativity and spatial awareness, and the left, language, comprehension, and arithmetic. The cerebrum deals with complex cognitive activities. It can be divided into four main lobes:
Frontal: complex thought, decision-making, planning, attention control, emotions
Parietal: movement, orientation, senses touch
Occipital: vision
Temporal: language, memory, hearing, sequencing
Cerebellum: Located under the cerebrum and at the back of the brain, the cerebellum coordinates muscles and is responsible for balance.
Brainstem: It connects the cerebrum and cerebellum to the spinal cord. It controls many involuntary actions, like breathing, digestion, and sleep and wake cycles.
Here is a diagram of these structures:
Other brain structures, located deeper within the brain, are:
Basal ganglia: controls fine motions
Limbic system: a more primitive brain part that deals with urges and appetites
Hypothalamus: controls internal organs’ functions (e.g. hunger, blood pressure)
Thalamus: helps relay information
So that’s basically how the brain works. It may seem relatively simple, but a more in-depth look would show just how intricate and phenomenal the brain really is. To get a hint of its complexity, did you know that the cerebrum alone has over 125 trillion synapses?! People still don’t understand all of the brain’s workings. Psychology Today writes, “…we still remain ignorant of how the brain coordinates all of its activities and develops language, thought and a sense of self.” One professor, Stephen Smith, says, “[Scientists] found that the brain’s complexity is beyond anything they’d imagined, almost to the point of being beyond belief.” So one of the big challenges of modern science, along with studying the bottom of Earth’s oceans, the Milky Way galaxy, and deep space, is figuring out the human brain.
People are complicated—every person has his/her own personality, a complex inner mind, and takes years to really know. It is simply astounding when we realize that a brain—a three-pound pinkish-grayish wrinkly mass—is behind each and every person. Will we ever know all of the brain’s secrets? Maybe. But at this point in time, neuroscience still has a great deal to go.
Sources:
Garrett, Ph.D., Mario. "Complexity of Our Brain." Complexity of Our Brain. Psychology Today, 25 Feb. 2014. Web. 21 Jan. 2015. <http://www.psychologytoday.com/blog/iage/201402/complexity-our-brain>.
"Brain Anatomy." Brain Anatomy. Mayfield Clinic, 1 Jan. 2013. Web. 21 Jan. 2015. <http://www.mayfieldclinic.com/PE-AnatBrain.htm#.VL2CLcksqz4>.
Moore, Elizabeth Amrstrong. "Human Brain Has More Switches than All Computers on Earth." CNET Magazine, 17 Nov. 2010. Web. 21 Jan. 2015. <http://www.cnet.com/news/human-brain-has-more-switches-than-all-computers-on-earth/#ixzz15KimfLp>.
Brain diagram source:
http://www.yourbrainattack.com/brain-functions.htm