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The Nervous System can be split into two main groups: the peripheral nervous system and the central nervous system.  Within the peripheral nervous system, there are two more groups: the autonomic, which controls self-regulated organs or glands, and the somatic, which controls voluntary movement of different skeletal muscles.  Then within the automatic system, there are two more groups, the sympathetic, which is arousing, and the parasympathetic, which is a calming system.  The two systems work together to almost keep balance in the body.  The sympathetic system is a biological response to some situation which can result in sweaty palms, raised heart rate, inhibits digestion, the stopping of salvation, dilated pupils, and other bodily functions.  It is important to differentiate the fact that the sympathetic nervous system does not account for how you choose to fight or how you choose to fight.  If you decide to run away from a scary situation, that would not be your sympathetic nervous system, that would be your somatic system because you chose to run away, it was not a biological impulse. 

 

Source: https://neuroamer.com/2017/06/19/what-happens-to-the-body-following-simultaneous-stimulation-of-the-sympathetic-and-parasympathetic-nervous-system-autonomic-conflict/

As you can see in the picture, the sympathetic system is located in the center of the spinal cord (which is also where the CNS is) and operates through fast-firing neurons.  The sympathetic system releases adrenaline.   The Parasympathetic system occurs in both the brain and the sacral spinal cord.

I have had the first-hand experience with both parts of the autonomic system.  When I was going into my freshman year of high school I went to France with my family and my friends.  We went to Lake Annecy and swam a lot.  We ended up sailing to a beautiful cliff jump.  All of my friends went to free climb a slippery cliff.  I watched my friends climb up and jump off.  I knew they would ask me soon why I am not doing it too.  Right before I started to climb I could feel my heartbeat quicken, my hands start to sweat, my breathing becomes uneasy, and I thought I had to pee, but I did not fight and I did not fly away, I started to climb.  As I got higher and higher I could feel the “symptoms” getting worse.  As I reached the top I felt the most intense part of the “symptoms”.  I knew that I would have to jump soon so I stood for a little to try and get my breathing back to normal and then I jumped.  Honestly, it was one of the most terrifying things I have voluntarily done.  Once I hit the water I felt my body almost instantaneously calm down.  I could feel my heartbeat go back to normal, my breathing normalizes and could tell my body was in a more calm state.  I can thank the parasympathetic system for that.

After reflecting on all of the concepts and theories that we have learned so far, one that stood out to me was operant conditioning with positive reinforcement. Positive reinforcement involves the addition of a reinforcing stimulus following a behavior that makes it more likely that the behavior will occur again in the future. This theory was introduced by BF Skinner and he showed how this theory worked through his experiment called the Skinner box. In the Skinner box, he placed a rat inside the box that contained a lever. When the rat would knock down the lever a food pellet would drop into a container next to the lever. This caused the rats to quickly learned that they would be rewarded if they just knocked down the lever. This goes to show that positive reinforcement strengthens a behavior by providing a consequence that would make an individual seek for a reward.

Positive reinforcement occurs in everyday life and more often than you think. I remember when I was in grade school in order to watch television during the week I had to complete my homework first. Completing my homework allowed me to be rewarded with watching whatever was on TV. This caused me to complete my homework in a fashionable time because the faster I got it done, the more time I had to watch television. Over time, this created a stimulus in myself that made me want to complete the homework. And that is not the only thing that involved positive reinforcement in my life. In high school I played football and in practice you are rewarded on how how hard you work and the passion you show in your craft. If a player followed those traits then they were rewarded by playing and starting in the games. This creates motivation to work harder and urges the player to give a lot more effort when it was time to practice.

These examples just go to show that the world is ran through positive reinforcement. It pushes people to complete a task and it gives them a goal or reward to look forward to when they complete the task.

 

The concept I am choosing to write about is Magnetic Resonance Imaging or MRI’s. I was never sure what an MRI was, but I knew it was similar to an x-ray. An MRI is different in from an x-ray in many ways. An MRI is a machine that allows doctors to look at soft-tissue with out opening the body. This allows doctors to see tumors, tears, or narrow slices. The MRI machine allows doctors to see very detailed and important parts of the body without making any incision. This machine was a huge advancement in the medical field because it can see almost every detail; this is due too the machines great spatial resolution. The spatial resolution on an MRI scan can go millimeters, so the doctors can see all the tissue and organs. My first experience with an MRI was this past school year. During the school baseball season, I dislocated my shoulder, an obvious injury the doctor can see from outside the body. However, the doctor told me it was necessary for me to receive an MRI in-order to tell if I tore any of the muscles in my shoulder. I had gotten x-rays in the past, but the MRI experience was much different. I laid down on a bed and was put into this big machine. After 15 minutes or so I was pulled out of the machine and was sent home. When my results arrived, they found further injury. The doctor told me I had torn my labrum and had chip out on my shoulder socket due to my shoulder being popped back in. The MRI allowed the doctors to see past just the dislocation and discover that I had torn a ligament. This related back to class because doctors always use MRI’s. They are often used to study the functions of the brain. Doctors can have patients perform task while they use an MRI’s to watch different functions of the brain. This was a huge advancement because previously they would have to open the body but now they can use this machine to study vital organs while patients complete tasks that make the brain work in different ways.

The nervous system is controlled by electrical and chemical signals between nerve cells called neurons. These neurons (shown below) communicate with each other through chemicals called neurotransmitters. When a neuron receives an electrical impulse of a certain magnitude, it travels from the dendrites to the axon and down to the axon terminals. This is called an action potential. The neurotransmitters are stored in the axon terminals, and are released into the synapse, which is the space between two neurons. These neurotransmitters fit into the dendrites of the receiving neuron like a lock and key and set off an action potential in that neuron, creating a chain reaction.

(from https://medicalxpress.com/news/2018-07-neuron-axons-spindly-theyre-optimizing.html)

Different neurotransmitters produce different psychological and physiological responses. For example, serotonin affects mood, hunger, sleep, and arousal. Low levels of serotonin lead to adverse effects. Chronically low levels of serotonin lead to clinical depression. Agonist drugs can mimic the effects of certain neurotransmitters, which is why Prozac has proven to be effective in treating depression by imitating serotonin in the body.

Even people who do not have a clinical mental illness are affected by different levels of neurotransmitters on a daily basis, and there are different ways that we can naturally increase serotonin levels. My favorite way to improve my mood by increasing neurotransmitter levels is exercise. Most runners describe a “runner’s high” after intense physical activity. Of course, this is different from getting high from drug use, but some components are similar. Like Prozac, many recreational drugs are agnostic drugs that mimic the effects of serotonin and other mood-enhancing neurotransmitters. Exercise causes the body to naturally produce more serotonin and endorphins, which improves the mood.

A little bit of exercise can make a big difference. Sometimes I jog for ten minutes if I don’t have time for a full workout, and even that is enough to improve my mood for the rest of the day. Understanding the biology of why we feel the way we do can help us to make choices that improve our overall mental health.

 

In our fourth lecture in Psychology, we learned that everything psychological is simultaneously biological through beginning to understand the complex function of the nervous system.  More specifically, we learned about the information system built from billions of interconnected cells called neurons. A neuron is the basic working unit of the brain; it is a cell that transmits information to other nerve cells, muscle, or gland cells. Neurotransmitters can often be referred to as “chemical-messengers”. They are molecules that transmit information between neurons, or from neurons to other parts of the body. You may have heard that depression is the result of a “chemical imbalance” in the brain. According to Harvard Health Publishing, “Research suggests that depression doesn’t spring from simply having too much or too little of certain brain chemicals. Rather, there are many possible causes of depression” (“What Causes Depression” 2019). My grandmother has suffered from depression for many years now. In 2018, she was hospitalized for her depression for several months in a rehabilitation center in Altoona. This was an extremely hard time for my family. My grandmother has been forever changed by her depression. She went from a being an energetic and loving individual, to becoming inverted and distant. She barely talks anymore. I hope and pray that with time and treatment she will be back to herself again. A reason for my grandmother’s severe depression could be attributed to how her nerve cells communicate with each other. According to Harvard Health Publishing, “Brain cells usually produce levels of neurotransmitters that keep senses, learning, movements, and moods perking along” (“What Causes Depression” 2019). To further explain, in some people who are severely depressed like my grandmother, the complex systems that accomplish this malfunction. Receptors can be both over and under-sensitive to a specific neurotransmitter. One of the big neurotransmitters believed to influence depression is serotonin. My grandmother takes medication that functions to help her low serotonin levels reuptake. I hope with more research, my grandmother can find a medication that works for her.  

MLA Citation

“What Causes Depression?” Harvard Health Publishing, Harvard Medical School , 24 June 2019, www.health.harvard.edu/mind-and-mood/what-causes-depression.

Top down processing is one of the ways the brain processes information. It is fundamentally different than bottom up processing.  Bottom up processing is when the brain takes in as many sensory details as it can and then forms an image, sound, or thought in our head. Top down processing is when the brain utilizes information that it already has, such as past images, experiences, or feelings to process information. Top down processing is the reason we don’t need all the letters of a word to be able to read it, and why some people see different images when shown the same picture.

In sports, especially baseball, top down processing is used all the time. The game simple moves too fast to be able to use bottom up processing.  If a player tried to take into account all the details of a pitch; like speed, spin, location, and movement, as it was coming towards them, the ball would be in the catchers mitt before they could even think about swinging. I remember my coach always telling me that all thinking should be done before you get in the box. Once you’re up to bat, your mind should be clear. This is why players need to rely on years of experience and pitcher’s tendencies during an at bat. For instance, if a pitcher throws a curveball, you are not telling yourself in your head that its a curveball coming towards you, your brain is just able to recognize it and tell your body how to react because it has seen so many curveballs before. This is why many hitters struggle with lefties or with pitchers who have unique deliveries or arm slots. These pitchers are less common, so the brain has less prior knowledge about what the ball looks like coming out of their hand and how it will move. This makes it more difficult for the brain to use top down processing and instead has to rely on bottom up processing, making it harder to stay relaxed and focused while up to bat.

Below is a video of multiple pitches overlapped into one video. As you can see, all the balls start in the some place, but wind up in totally different places at different times. If the batter was to use bottom up processing, they would never be able to recognize the pitch in time. Instead, the batters brain is using prior knowledge about what the pitcher is likely to throw in that count and how the pitch looks compared to other pitches he’s seen in a prior at bat or even a different game. Overall, top down processing is what allows baseball players, and other athletes, to make decisions so quickly without taking into account every sensory detail they are experiencing.

The human body has so many functions that control us on a daily basis but the body makes up an excessive amount of signals that we cannot always come to terms with or understand why our bodies send these signals to us when certain situations happen. The sympathetic nervous system is one of those signals that our body sends us when we experience a stressful, overwhelming or high intensity situation or activity. The sympathetic nervous system makes up a part of the autonomic nervous system which contains two divisions; the sympathetic and parasympathetic nervous system. Both of these divisions are controlled by our body and we simply do not have control over them because our bodies naturally send these signals to us when we experience an overwhelming, stressful situation and then the aftermath of our bodies returning to regular heart race and blood flow. In other words, when our bodies prepare to experience something intense, our sympathetic nervous system activates which causes our blood flow to increase, excessive sweating, dilated pupils, heavy breathing and speedy heart rate and then as we work through the experience the parasympathetic nervous system helps our body get through it and return to that “safe” feeling. The sympathetic nervous system is a feeling that no person can escape entirely because at some point in life everyone faces a situation that scares them, makes them angry, sad, stressed or excited. All of these emotions will result in the body activating the sympathetic nervous system to prepare you for this sensational feeling. A time where my sympathetic nervous system came into play was last semester in my Geary Hall dorm where my two friends decided to wake me up from a dead sleep and pretend they were an intruder. There was no rhyme or reason for my friends to play this joke on me other than pure boredom and the fact that they lived 2 floors above me. It was probably around 12am when I fell into a deep peaceful sleep until I was woken up from an alarming, aggressive loud knock on my door. I sprung up out of bed and stared at the door for about 2 seconds until the loud banging picked up again. My stomach fell into my toes practically, I was dripping sweat, my body felt like it was throbbing, my heart was pounding so hard that I felt like I could literally hear my heart beating and I could hardly think straight. In this moment I had no place to run and only so many places to hide so I squatted on my bed frozen not knowing where to go or what to do. The banging continued and within a few more seconds I heard, “OPEN THE DOOR.” With all of my emotions coming into play I began to come to terms with the fact that I was going to die. I could not even control the way I felt and I could not control my heart rate or excessive sweating, in fact all I remember was feeling like I was going to pass out and die. All of a sudden I heard my phone ring and saw a text saying, “ITS ME DON’T CALL THE POLICE.” In that moment my whole body felt relieved and I felt absolutely exhausted but safe and happy at the same time. There was no better feeling in the world then that moment walking over to my door and being able to open it knowing I was not going to die and it was just my friends. This situation that I went through of anxiety and fear related to the sympathetic nervous system because my body responded the exact way it was supposed to. My blood flow increased, my heart was racing, I was sweating and I experienced that feeling of my muscles being so tense. My situation is also related to the repercussions of the parasympathetic nervous system. My body then came back to all of its normal levels after that feeling of anxiety and fear left my body and I was able to relax by feeling safe and comforted. The bodily functions are all very interesting but these divisions of how our nervous systems react and prepare us for certain situations really prove how much our bodies can really do and produce for us.

 

Work Cited

“Nervous System: To Lift or to Rest?” CrossFit Holland Michigan – Try a Free CrossFit Class, www.crossfitlakeeffect.com/nervous-system-to-lift-or-to-rest.

“Fight or Flight: The Sympathetic Nervous System.” LiveScience, Purch, www.livescience.com/65446-sympathetic-nervous-system.html.

Recently in class, we have discussed the visual system. Upon going over this system, we were able to discuss how this system works and the different areas of the eye. One thing that I thought was very interesting was phototransduction. This is the conversion of light energy into neural impulses. I find it very interesting that no two people can see the exact same in terms of colors and perceptions. From what I understand, the stimulus input of light energy varies for everybody. On the electromagnetic spectrum, humans are only able to see “visible light”. This “visible light” is seen through the wavelengths and intensity. The wavelength is the distance from the peak of one wave to the peak of the next. This is related to how humans perceive hue, or color. In addition, the intensity (brightness/lightness) refers to the amount of energy in a wave. This is how humans are able to perceive brightness. However, the different perceptions vary from person to person. I believe that this goes along with the saying of, “My color red is not the same as your color red.”

However, something that is held in common is that all humans are able to see with their eyes. This may seem like an obvious statement, but it actually is very complex when thinking about how the different parts of the eye work together to perceive and interpret colors and visuals in their own unique way. The first part of the eye that we learned about is the cornea. The cornea is the transparent tissue where light enters. Next is the iris, which is a muscle that changes the opening in the eye by expanding and contracting. This opening is known as the pupil, which also lets light in. The lens in the eye focuses rays of light on the retina, and the retina holds sensory receptors which process visuals and send the message to the brain.

Learning about the eye caused me to recall an experience of my own where my eye was injured. In the middle of a soccer game, the ball was kicked into my face at exactly the right angle to hit my eye directly on. This hit actually caused a bruise on my cornea. Upon the initial hit, the vision in my affected eye partly went black. When one part of my eye was injured, I can assume that this messed up my visual system, causing the impaired visual. At the eye doctor, I was able to see a type of x-ray that showed my eye. I remember the doctor showing me the different parts of my eye, all of which we discussed in class. I was also able to actually see the bruise that was on my cornea through this “x-ray” process as well. I thought that it was really cool to be able to discuss the parts of the eye and how these parts of the eye work together to create the visual system in which we are able to perceive things. I was then able to relate the class discussion to actual images of my own eye that I could recall seeing in the picture.

Psych blog post 1

Click on the picture of the youtube video!