Parts Of The Brain And Their Function

Tutorial: The Brain
The brain was a mystery for a very long time. Modern imaging has allowed us to study the brain and locate where important functions are occurring. Please remember that the functions do not happen in just one area of the brain. Many neural layers and areas are found in any one activity that happens. But what we do know though is that some areas do appear to be predominantly involved in certain functions. We will learn about the brain in the three-part model. We’ll first look at the hindbrain. The hindbrain is located where the spinal cord goes into the cranium. The first area that we see if the medulla. It is the swelling at the tip of the spinal cord. It is concerned with all of our automatic functioning, such as breathing, heart rate and swallowing. We do not have to think about these things, they happen automatically. Inside the medulla is a part called the reticulum activation system. It is concerned with arousal, attention and sleep. The second part of the hindbrain that we see is the cerebellum. The cerebellum is sometimes called the small brain. It controls all of our fine motor functioning and balance. For example, when you first learn to ride a bike, you have to think about everything you do. After you learn to ride a bike, it becomes totally automatic, and that is because of the cerebellum. The next part that we see is the pons. Pons means bridge in Greek and that’s exactly what the pons is. It is a bridge taking in all of our sensory information and taking it to the cortex to be interpreted.
The second part of the brain is the midbrain. The midbrain takes all of the incoming neural information and channels it to the correct part of the cortex to be interpreted. It is also involved in muscle tone and helps in sleep, wakefulness and attention.
The forebrain is the last part of the brain to be studied. It is the most complicated part of the brain, and it is what separates us as human beings from other animals. When we first look inside the skull, what we see is the cerebrum. The cerebrum is composed of two parts called hemispheres. One is on the right side and one is on the left side. The outer covering of the cerebrum is called the cortex. It is made up of what is called convolutions – the worm-like structures that you see when you look at the brain. We can look at the cortex in another way and divide the cortex into four sections called lobes.
The function of the lobe is to interpret information coming in from our senses. Located in the back of the head is the occipital lobe. The occipital lobe processes visual information, or what we see. Coming to the top of the head is the parietal lobe. The parietal lobe processes information on pain, touch, temperature and pressure. Located on the sides of our head, right above our ears, are the temporal lobes. The temporal lobes process auditory information, emotion, and have a part in memory. Located right above our forehead is our frontal lobe. It is the largest part of the cortex and the part of our brain that makes us human. It is involved in speech production, logical and rational thought, and has the ability to understand and plan the future. There are two areas behind the frontal lobe. The first one is the motor cortex and it interprets our muscular sensations. Right behind it is the sensory cortex and it is the part of the cortex that tries to coordinate all of the information coming in from all of our senses.
© KC Distance Learning

On the inside of the cerebrum is the limbic system. The limbic system is a primitive part of the cerebral cortex. It is made up of several parts that have a function in the everyday working of the brain. The first part is the corpus colossal. It is a band of nerve fibers that hold the right and left hemisphere together. It allows the right side of our brain to know what the left side is doing, and the left side to know what the right side is doing. The second structure is the thalamus. The thalamus is sort of a relay center of the brain. It takes in all of the sensory information and takes it to the cortex to be interpreted, and takes it from the cortex back to the spinal cord to get back to the body. The next part is the hypothalamus. The hypothalamus controls all of our drives and tries to maintain homeostasis. Homeostasis is an equilibrium at which our body functions best. The hypothalamus controls drives such as hunger, thirst and sex. The next structure is the hippocampus. The hippocampus is very important in the processing of our short-term memories into long-term memories. This is the part of the brain that is first attacked by the disease Alzheimer’s. The hippocampus also helps us in facial recognition. The next part is the amygdala. The amygdala adds emotion to memory. It also has a direct role in the formation of our memories. Located inside our frontal lobe are two areas that help in our speech production. The first is Broca’s area. For most people, all right-handed people, and most left-handed people, Broca’s area is located in the left hemisphere.
This allows us to speak. It coordinates what we want to say with our tongues and our muscles. The next area is located a little bit behind Broca’s area more toward the temporal lobe is Werniche’s area. Werniche’s area allows us to understand what is spoken to us.
Patients with severe epilepsy have allowed us to discover another important concept about our brains. To help severe epileptics when drugs failed, a dramatic operation was performed and it involved cutting the corpus collosum. As you can remember, the corpus collosum is the band of nerve fibers that holds the hemispheres together.
Separating the hemispheres allows the seizures to be localized and not spread from hemisphere to the other. The split-brain patient will learn that the hemispheres will have distinct, different functions. This is called lateralization. The left hemisphere controls the right side of the body. It also coordinates our language abilities because it has both
Broca’s area and Werniche’s area in it. The left side is also the logical, rational brain and excels in such areas as science and math. The right hemisphere controls the left side of the body. It excels in spatial abilities. It is our artistic and musical part of our brain. It also has a function in detecting and emoting emotions. In all but split-brain patients, we use all of our brains and both hemispheres since they communicate with each other. The right hemisphere knows what is happening in the left hemisphere, and the left hemisphere knows what’s going on in the right hemisphere.
Here is a fun activity for you to try. You will need four sheets of paper and a pencil. You need to be right-handed or find a friend or family member who is. Put a pencil in our right hand and tap a sheet of paper for one minute. Take the second sheet of paper and put the pencil in your left hand and tap that sheet of paper for a minute. Now switch
© KC Distance Learning

back to your right hand and tap the sheet of paper for a minute, but for the entire minute talk. Repeat the same thing with the left hand for one minute while you’re talking. You should see a decrease on the paper in the amount of taps in the right hand taping while you were talking. The reason for this is that the right hand is controlled in the left part of the brain. Language is also controlled in the left part of the brain, and because of this, the brain is competing for both things going on at one time.

© KC Distance Learning