Unit 4 Reflection

This unit focused on the integumentary system. We explored the various layers of the skin (which are shown and labelled in the diagram below) and the purposes that the skin serves, for example, maintaining homeostasis and protecting the body. We also discussed how accessory organs like cutaneous glands, hair, and nails are formed and how they all work together with the skin to protect our bodies. 

We also touched on the Immune System, which consists of many different factors varying from nonspecific to specific that work together to defend the body against pathogens. The human body's first line of defense against invaders is non-specific resistance, which mainly involves the skin and mucous membranes, but also includes the epiglottis, urine flow, defecation and vomiting, tears, and saliva. Various chemical methods of nonspecific resistance like sebum, perspiration, lysozyme, and gastric juice work alongside the skin and mucous membranes to protect the body. If the pathogens somehow evade this first line of defense, eosinophils, basophils, neutrophils, and macrophages, which make up the second line of defense, work to inhibit the pathogens. Both the first and second lines of defenses are non-specific and will attack all pathogens. If the pathogen still manages to get by these two lines, the third line of defense - the specific response - will take place with the help of lymphocytes that differentiate into B cells and T cells and react to a particular antigen (a part of a pathogen). B cells and the antibodies they produce go on to neutralize pathogens or trigger complement proteins to cause cell lysis or attract phagocytes that take in the pathogen. T cells, on the other hand, release toxic substances that directly trigger apoptosis (programmed cell death). A comparison of how B cells and T cells work to defend the body against pathogens is depicted in the image below. We also discussed how benign and malignant cancers come about and can result from genetic and environmental factors. 

I almost fully understood most of this unit as it was a reinforcement of the most recent unit in AP Biology. I'm still a little bit confused as to how tumors arise and how they manage to evade the three lines of defense in our immune response. I still wonder as to how the glands in the integumentary system work and how nerve fibers get signals to the brain when we touch something and what, if any, role does the tactile corpuscle play in this process.

This unit solidified what I've learned about myself and my studying habits all through high school: I most definitely am a visual and verbal learner. As I was reading the textbook and filling out the reading guides for this unit, I found myself constantly drawing and labelling diagrams of the layers of the epidermis, the different types of white blood cells, and how T cells and B cells reacted differently when they encountered a pathogen. I've learned that diagrams really help me understand what we are learning about by making the material more tangible and "real" rather than theoretical. It really helps me to relate concepts we learn in class to everyday life; for example, using a hypothetical scenario of someone getting the flu or cancer and talking through or drawing out what that would potentially look like in the person's body on a cellular level. I think this is one of my major strengths, especially when it comes to science classes like biology and anatomy, as much of what we learn can be drawn or mapped out, making it easier to understand the bigger picture. A major weakness of mine is definitely memorizing specific details and applying them to that big picture, but I think my strength of visualizing and drawing out diagrams really helps me remedy this weakness. 

According to the VARK Questionnaire, I have a multimodal learning preference, meaning using visual aids, diagrams, and writing things down generally helps me learn. My scores from the VARK Questionnaire were visual: 9, aural: 8, read/write: 9, and kinesthetic: 11. I've been experimenting with studying strategies in some of my other classes and I think I agree. When studying for AP Biology, for example, I take notes from the textbook and then add in details from class lectures and try to incorporate diagrams or flowcharts to make sense of what the chapter discussed. The results from the VARK Questionnaire are generally what I thought they would be because I prefer using spatial diagrams and images, words (both written and spoken), and using my body, hands, and sense of touch to help me learn. I will definitely incorporate these techniques when studying for the upcoming Unit 4 Test, by actively studying: drawing out diagrams, taking notes from the textbook by hand, and maybe explaining the unit to a friend or classmate verbally to help me make sense of all the information.