Week 3 Microscopy Lab - lab work PDF

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BIOS251 OL, Week 3 Lab Name: Dhruvi Patel

OL Lab 3: Microscopy Learning Objectives:

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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.

BIOS251 OL, Week 3 Lab Name: Dhruvi Patel

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 how the external factors effects our internal system and how the tissue cells functions when a virus enters the body through the microscope.

Observations: List 3 observations you have made in this simulation. 

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If an antigen, like viruses (gluten in part 1) detected by the immune system lymphocytes are recruited to the epithelium. The lymphocytes migrate into the epithelium to fight the intrudes and sends out a variety of immune stimulators and triggers the inflammations. One of the main stains are Eosin used for H&E staining technique, in part one we used the mixture of anilin, orange G, and Fuchsia. The villi enlarge surface area of small intestines by approximately 50 times and the enlarge surface allows more efficient nutrients update. Goblet cells are the main secretory cells of the epithelium which produce large amount of mucin. the image of epithelium at station three shows the virus infect lymphocytes specifically, which somehow maintain delays the immune response and the one set of inflammation.

Answer all the questions below: 1. Distinguish the light microscope from the electron microscope. (1 point) a. Light microscope is used to identify different structure of the small intestine through the beam of lights. Whereas the electron microscope utilize electron instead of light to examine cellular structure in high detail. 2. Draw the three types of muscle tissue (3 points) Smooth Muscle Tissue

Skeletal Muscle Tissue

Cardiac Muscle Tissue

BIOS251 OL, Week 3 Lab Name: Dhruvi Patel

3. What type of cells lines the intestinal lumen? (1 point) o Cells of epithelial tissue that lines the intestinal lumen. 4. Provide the function of the following cell junctions: (4 points) a. Tight junctions: form fluid-tight seals between cells and are common among epithelial cells that line the stomach, intestines, and urinary bladder. They inhibit the passage of substances between cells and prevent the contents of these organs from leaking into the blood or surrounding tissues.

b. Adherens junctions: are made of plaque and anchor cells together. Help epithelial surface resist separation during various contractile activities, as when food moves through the intestine.

c. Gap junctions: allow cells in a tissue to rapidly communicate through connexins, transmembrane protein channels that connects cell together. Gap junctions also enable nerve or muscle impulses to spread rapidly among cells.

d. Desmosomes: contain plaque and have transmembrane glycoproteins that extend across a gap between adjacent cell membrane and link they cytoskeletons of cell together.

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? o Coeliac Disease which is a severe case of gluten intolerance. The immune system of intolerant individuals identifies the gluten as an intruder and causes inflammation of the small intestine. If a person with gluten intolerance continue to consume proteins the intestine remains in a constant state of inflammation which leads to a decrease of the absorptive surface of the small intestine and cause deficiencies in nutrient uptake. o Goblet cells- the main secretory cells of the epithelium. They produce large amount of mucin, a protein that is the main component of mucus. The Secreted mucus lubricates linings of digestive, respiratory and reproductive tracts, and urinary tract. It helps prevents destruction of stomach lining by acidic gastric juice secreted by stomach.

BIOS251 OL, Week 3 Lab Name: Dhruvi Patel...