Levi Myers

Biology of Disease

Curated Paper 2: Brains and Guts

10/28/2016

Brains and Guts

For this paper I would like to discuss some of the connections that I have bee able to make as they relate to different areas of my life. These past few weeks we have been talking about neurological and gastrointestinal diseases. We have been going over mechanisms of these diseases and applying them to some of the diverse symptomology that can be seen in the populous. We started out our discussions with neurological disease. The first connection I made was involved with a very common disorder in the United States called Alzheimer’s. Alzheimer’s disease (AD), is caused by the formation and accumulation of two proteins called A b amyloids and Tau. These proteins cause problems when one of two things happens. First there is excessive formation of these proteins and this is followed and compounded by the ineffective removal. As these proteins build up they interfere with the workings of the cortex and eventually lead to death. These plaques form and build up on the folds of the most external portion of the brain the cerebral cortex. As this pressure builds up it causes the death of the neural tissues. These proteins form in very specific regions of the brain and one of the first steps of the disease is the generation of the defective amyloid plaques that cover the folds of the brain. As these proteins form they take the space of the cortex and brain mass is lost. This results in the loss of many vital functions necessary for essential human interactions.

A few years ago my grandmother was diagnosed with Alzheimer’s disease. After a time of dealing with the disease she became incapable of living on her own and needed to be cared for. This responsibility fell on my family and she moved in with us.  Because of this I was able to see what this disease does first hand and studying it allowed me to understand some of the things I saw her do. There was one day this semester in particular where I was studying the pre frontal lobe with some of its associations and functions were. These generally deal with the long-term planning and higher thinking abilities. In my readings there was a study done on people who had gotten frontal lobotomies and they had a bunch of weird effects. These patients lost the ability to complete complex puzzles and were unable to perform multiple tasks at the same time. They were talk but these conversations tended to be short and long concepts tended to be too much for them to grasp. Similar effects happen to people who have this disease. My grandmother for example suffered from similar things. Early on in her disease there was almost no noticeable difference until we started talking about something new or the conversation was longer than 10 or 15 minutes. In these situations the flow of the conversations would be off. She would not be able to remember the direction of her thoughts. As her disease progressed it was obvious that she was loosing her ability to communicate. She slowly digressed from more complex language and concepts to short phrases and lower vocabulary. This continued until she was more or less unable to speak. This led me to research what parts of the brain were the most used in both spoken and interpretation of language. From my studies I was once again able to connect these memories with something that I studied called the Broca’s and Wernicke areas. These areas are used in the production and interpretation of speech. There are hosts of diseases that deal with problems in these areas such as Broca’s aphasia and where an individual is able to think of words but not able to speak them or they are jumbled and make no sense to the listener. However the words would make sense to the person speaking them. I was able to connect these things to our studies of Alzheimer’s.

After this we delved into the mysteries of gastrointestinal diseases that have been on the rise over the last few decades. In my studies I came across a couple of these diseases and made the following connections. First I studied about ulcerative colitis. This is a nasty disease that is very informative in its name. The patient will suffer from ulcers that occur in the lower regions of the large intestine or colon. While I was volunteering in the emergency department we would have people that came in with what the doctors called GI bleeds. I was a good friend with one of the physicians there and he told me that he could tell where in the GI tract a bleed would be just from the color of the stool. I pondered this at the time and the thought resurfaced as I was researching the gastrointestinal tract. After reading about ulcerative colitis I learned that blood would generally be darker the higher in the GI tract that the bleed starts. The heme of the blood gets destroyed and parts of it are reabsorbed in the intestines. The longer the blood is in the intestine the longer it has to become digested. This made the doctors comment finally come into focus. Another time in the Emergency department we had a patient that had had some head trauma and the doctor used lights to test the responsiveness of his pupils. I studied about something that I have never heard of before called the thalamocortical system. Almost all of the sensory information processed by the brain has a relay system that incorporates the thalamus and the cortex. These signals travel from the thalamus to the cortex and then back to the thalamus where other signals are sent. This is interesting in that when this connection is severed in any way the brain has a very hard time with communicating to the rest of the body. We learned about the connection pathways in the brain and this is one of the reasons that they do the test. If both pupils dilate then the connection is not in immediate danger if only one eye dilates then there is a big issue with the neuronal connections and they can expect cerebral damage.

            Lastly I had a friend in high school that had rather sever lactose intolerance. This problem while not life threatening caused him to have to make a lot of changes in his diet that reduce the side effects of eating things with large amounts of lactose. I learned from our discussions in class and from my reading that humans are the only mammals that continue to drink milk past their infancy. For most, the enzyme lactase is only substantially active during these early years. After this time the expression decreases. It so happens that about 70% of humans have an altered allele that allows for production of lactase throughout their lives.  Overall I was able to learn a lot from our studies and to make sense of the life that I have lived through making connections to scientific principle we talk about.