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How Does the Brain Work?

 


   The main functional unit of the brain is a type of nerve cell called the neuron, of which the human brain possesses roughly 100 billion. The human body contains three types of neurons, each different in function. Sensory neurons carry signals from the outside world into the central nervous system. Motor neurons carry signals from the central nervous system to muscles and glands. Interneurons form a connection between other neurons; they are neither sensory nor motor. Each sensation, memory, thought, and movement we experience is the result of electrochemical signals that pass Through neurons. The ability of our brain to function is the result of the 24/7 activity of neurons.

   

    The human brain consists of the brain stem, the cerebellum, the cerebrum, and
the limbic system.The BRAIN STEM contains the medulla, which regulates heart rate and breathing; the pons, which links to the cerebellum to help with movement and posture, as well as creating a certain level of consciousness necessary for sleep; and the midbrain, which helps regulate body movement, hearing, and vision.

   

   The CEREBELLUM, often called “thel ittle brain,” allows the body to movep roperly, controlling functions such as posture, balance, and coordination. The CEREBRUM is the largest part of the brain, and responsible for most of its functions. It is divided into four sections:
   (1) the frontal lobe, which controls, among other things, intellect, judgment, creative thought, problem solving, muscle movements, smell, and personality; 

  (2) the parietal lobe, which focuses on comprehension and monitors visual functions, reading, and tactile sensation;

  (3) the temporal lobe, which controls visual and auditory memories; and

 (4) the occipital lobe, which is responsible for processing visual information. The cerebrum is split into a left and a right hemisphere, connected by neurons that pass information from one side to the other.

  

   The LIMBIC SYSTEM contains glands that help relay hormonal responses in the body. The amygdala is responsible for the response and memory of emotions, especially fear. The hippocampus helps process long-term memory and emotional responses. The hypothalamus controls hunger, thirst, and body temperature, while the thalamus helps control attention span and monitors information in and out of the brain to track bodily sensations, such as pain.

  

    The regions of the brain frequently work  independently, but sometimes different regions work together to perform a task. For example, several regions in the brain function cooperatively to allow us to read. MRI brain scans show that the ability to sound out printed words is a function of a part of the parietal lobe, while making connections with a new word and sound is associated with the cerebellum and hippocampus. The ability to read out loud quickly appears to be a function of several brain locations.

    

    Despites centuries of scientific study, however, we are at still at a loss to explain many of the human brain’s mysteries. Among the unsolved puzzles scientists are trying to unravel are the following: How are memories stored and retrieved? How do brains make sound predictions about the world? What does “intelligence” mean in biological terms? Getting a stronger grip on the functioning of the brain could have enormous ramifications. According to Norman Weinberger, a neuroscientist at the University of California, Irvine, “If we understand the brain, we will understand both its capacities and its limits for thought, emotions, reasoning, love, and every other aspect of human life.”

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