BIOS-251 Week 4 Lab Assignment: Microscopy (GRADED A)

OL Lab 4: Microscopy Learning Objectives: • Understand different microscopy techniques and their limitations • Identify various cell types and cellular structures • Understand staining techniques • Understand coelia ...

OL Lab 4: Microscopy Learning Objectives: • Understand different microscopy techniques and their limitations • Identify various cell types and cellular structures • Understand staining techniques • Understand coeliac disease and intestinal inflammation Introduction: Histology is an important tool of biology which helps us understand how tissues are structured and how they function. This is helpful when we are investigating diseased or malformed tissues. In this simulation you will examine a chicken intestine sample that is infected with a retrovirus and observe how the virus infects the lymphocytes (the cells that provide immune protection) and how it inhibits inflammation. Inflammation is a sign of tissue damage. You will use different microscopic techniques to examine chicken intestine slide. Try out the electron microscope Electron microscopes can be used to visualize objects that are too small to see when using a light microscope—for example the microvilli. You can zoom in and out to observe different cellular structures such as mitochondria and the cell. Using the 5X magnification, you will identify the villus, and then proceed with higher magnifications to identify smooth muscle, extracellular tissue, epithelial cells, Goblet cells and the nuclei. Learn about fluorescence staining techniques For example, by staining the DNA with DAPI, you can easily identify a cell’s nucleus. In this part of the lab, you will examine a chicken intestine sample that is infected with a retrovirus and observe how the virus infects the lymphocytes and how it inhibits inflammation. The retrovirus can be further developed as medicine for coeliac disease. Part 1: Complete Labster Microscopy Part 2: Report and Reflection Purpose: Describe in your own words and in complete sentences, the purpose of this experiment. The purpose of this experiment was to understand the components of microscopic techniques. It was meant to observe the inflammation effect the small intestine. You see how a virus affects cells. Observations: List 3 observations you have made in this simulation. 1.The infection of epithelial cells target the lymphocytes cells to fight the viruses present in the epithelium. 2. The body does not fully activate its immune response to fight the virus present if there is not an increase in lymphocytes cells in the body. 3. Celiac disease if the activation of immune response due to the presence of gluten proteins in the intestinal tract. Resulting in the body to inflame can cause damage to the body’s organs and tissues. Answer all the questions below: 1. Distinguish the light microscope from the electron microscope.(1 point) The light microscope uses a beam of light to produce the image of a specimen and the electron uses a bean of electrons that produces a higher resolution image. 2. Draw the three types of muscle tissue (3 points) Smooth muscle Skeletal muscle Cardiac muscle 3. What type of cells lines the intestinal lumen?(1 point) The cell type that lines the intestinal lumens are simple columnar epithelium. 4. Provide the function of the following cell junctions: (4 points) a. Tight junctions: Regulates the movement of substance between cells by forming a tight continuous barrier between epithelial cells b. Adherens junctions: Holds together the contracting fibers in cardiac muscle that allows contraction. c. Gap junctions: Gaps in connected cells that allow small molecules to pass through. d. Desmosomes: adjacent cells that are attached together by cadherin plaques located in the cell membrane and keratin, and used to maintain the tissues mechanical integrity. 5. Reflection: Reflect on at least 2 key concepts you have learned from this simulation. How would you relate it to the physiological functions of the body? One key concept I learned is that overreactive immune responses within the body that results in inflammation, resulting in tissue and organ damage in cases such as Celiac disease, in comparison to the body’s inability to respond to other viruses such as HIV. Another key concept I learned is that to the body’s key indicator of inflammation to reacting to virus and the presence of other foreign substance. I would relate it too the functions of the body because your body naturally regulates itself so the immune system will automatically fight off viruses that it senses. Grading Rubric: Activity Deliverable Points Part 1 Complete simulation 15 Part 2 Complete lab report and answer questions • Purpose (1 point) • Observation (3 points) • Questions (9 points) • Reflection (2 points) 15 Total Complete all lab activities 30