“I could while away the hours, conferring with the flowers – consulting with the rain. And my head I’d be scratching while my thoughts were busy hatching if I only had a brain.” These are the beginning lyrics to a famous song in the movie The Wizard of Oz. However, unlike the Scarecrow in Oz, we wouldn’t be doing much singing if we didn’t have a brain. In fact, we wouldn’t be doing much living either. So what is this thing that the Scarecrow lacked?
The brain is an organ. It is one of the most complex organs in the entire body. The brain allows us to see, taste, feel, move, smell, hear, think, breathe and talk.
In fact, it controls the entire body by first receiving information and then sending that information out to the proper organs, including the skin. For example, say you are sitting and you want to stand up. The brain takes in the information that you want to stand and it then sends that information to the muscles in the body to perform the action of standing up.
Did you know that the average adult human brain weighs about 3 pounds? A baby’s brain weighs less than a pound and then it grows in size until a person reaches their late teens, although some people in the medical field believe that the brain actually continues to grow up till a person is in their mid-20s. Regardless of when it reaches its maturity, the brain is 80% developed by the age of 2. Yup, at 2 years of age your brain is almost fully developed. No wonder why so much learning goes on with toddlers.
The brain is composed of 60% white matter and 40% gray matter and it is protected by the skull. The brain cells include neurons and glial cells. Arteries, veins and capillaries (also known as blood vessels) supply the brain with oxygen and nourishment. They also take away wastes. The cells of the brain will begin to die if the brain goes for 3 to 5 minutes without oxygen.
Neurons are cells that send and receive electro-chemical signals to and from the brain and the nervous system. The brain has about 100 billion neurons. The speed of the signals from the brain happens at a rate of up to 200 miles per hour.
Glial cells support the functions for the neurons. Because they support the neurons, their numbers are even greater. In fact, glial cells make up 90% of all of the brain’s cells.
PARTS OF THE BRAIN
The brain has three parts that are known as the cerebrum, the cerebellum and the brain stem or the medulla.
1. Cerebrum: The cerebrum makes up the bulk of the brain and it is divided into four sections or regions known as lobes. The four lobes are the frontal lobe, the temporal lobe, the parietal lobe and the occipital lobe.
The frontal lobe is responsible for a person’s behavior, problem solving abilities, creative thoughts, attention, intellect, judgment, coordination of movements, some emotions, some eye movements, the sense of smell, sex drive and physical reactions.
The temporal lobe is responsible for auditory memories (like remembering song lyrics), some hearing, visual memories, music, fear, sense of identity and some language and speech. In addition, the temporal lobe has two parts known as the right hemisphere and the left hemisphere. The right hemisphere controls the left side of the body, analyzes nonverbal information and communicates emotions. The left hemisphere controls the right side of the body and produces and understands language.
The parietal lobe is responsible for the sense of touch, appreciation, responses to internal stimuli, sensory comprehension and reading functions.
The occipital lobe is responsible for vision and reading.
2. Cerebellum: The cerebellum is located at the bottom of the brain and rests on the brain stem (medulla). It is responsible for the body’s balance, poster, cardiac (heart), respiratory and vasomotor centers.
3. The Brain Stem (Medulla): The brain stem is where motor and sensory pathways are to the body and to the face. It also links to the cardiac (heart), respiratory and vasomotor centers.
The brain and all of its functions is so complex that you could spend years studying it and still find new things to learn about it. However, you now have the basic beginning understanding of the brain. So, now let’s see just what you remembered.
