BIOS251 W5 Lab Instructions(1)

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Chamberlain University College of Nursing *

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251

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Biology

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Jun 19, 2024

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Week 5 Lab Instructions Integumentary System Activity Deliverable Points Part A Activity: Observing Prepared Slides of Epithelium 6 Part B Activity: Observing Prepared Slides of Dermis 6 Part C Activity: Prepping/Observing Wet Mount of Cheek Cells 6 Part D Lab Worksheet (Questions) 12 References: 1. Saladin Anatomy & Physiology: The Unity of Form and Function Part A Step 1: Read the Entire Lab Packet 1.0 – Read through the laboratory packet – SEE ATTACHED SHEETS Part A Step 2: Come to the Lab with Proper PPE BACKGROUND: The integument contains multiple layers (epidermis, dermis, and hypodermis) and various cell types in each layer. The outer layer contains five different cell types: stratified squamous epithelium, keratinocytes, melanocytes, Langerhans cells, and Merkel cells. The middle layer of the integument is referred to as the dermis, which is composed of connective and vascular tissue. The dermis and epidermis form the cutaneous membrane. Beneath the dermis lies the subcutaneous or hypodermal layer, which consists of loose connective tissue, specifically adipose tissue. PURPOSE: In this lab, you will be asked to observe prepared slides of the epithelium and dermis of human skin. You will also prepare a wet-mount of cheek cells and observe them under the microscope. Finally, you will demonstrate your knowledge by completing the Lab Worksheet. MATERIALS:  A copy of the lab report for each member of your group  A writing utensil  Prepared slides of epithelium, connective or vascular tissue  Crystal Violet stain  DI water  Glass slides and cover slips  Microscope BIOS251 Week 5 Lab Instructions Page 1 of 7

 Immersion Oil  Lens wipes  Toothpicks PREPARATION:  Read your lab in its entirety before coming to class.  Clear your workstation of all unnecessary materials. Book bags and or purses should be hung on hooks or places at the front of class. Make sure all other unnecessary materials (coats, drink containers, unused textbooks, etc.) are all stored and placed in a safe area out of the way.  Obtain all materials listed above.  Familiarize yourself with your lab materials.  Follow the directions of the packet and as presented by your instructor.  Students must wear safety eyewear, gloves and lab coat at all times.  Used glass slides and cover slips are discarded in waste glass container  Be aware of the instructions for documenting your lab work. You will be performing the lab in a group but will each be responsible for recording your own data and creating your own lab report. ACTIVITY: Part A - Observations of Epithelium We will observe cells in the most superficial layer of integument in this activity Method: 1. Obtain the preserved slide of epithelial cells. Your instructor may have one or more slides for you to observe. 2. Use Appendix A to follow instructions on using a Microscope. 3. Observe the slide under 10X, 40X and then using 100X objective lenses, following the directions from your instructor. Note to Students: Don’t forget to use oil with 100X lens only. After completing the observation, clean the oil immersion lens with lens paper to remove oil. Be careful to not contaminate other objective lenses (4X, 10X, 40X) with oil. 4. Record and describe your observations made using a low-power magnification (10x) and high- power magnification as directed by your instructor (40x or 100x). Make sure to note as many details as possible, and include the magnification used. BIOS251 Week 5 Lab Instructions Page 2 of 7

Observation: Epithelium 40X 100X 4 x 40 x Activity: Part B – Observation of the Dermis We will observe the cells in the middle layer of integument in this part of the lab. Method: 1. Obtain the preserved slide of connective and/or vascular cells. Your instructor may have one or more slides for you to observe. 2. Note to students: Use Appendix A to follow instructions on using a Microscope. 3. Observe the slide under 10X, 40X and 100X objective lenses as directed by your instructor. Don’t forget to use oil with 100X lens. Note to Students: Don’t forget to use oil with 100X lens only. After completing the observation, clean the oil immersion lens with lens paper to remove oil. Be careful to not contaminate other lenses (4X, 10X, 40X) with oil. 4. Record and describe your observations made using a low-power magnification (10x) and high-power magnification as directed by your instructor (40x or 100x). Make sure to note as many details as possible, and include the magnification used. BIOS251 Week 5 Lab Instructions Page 3 of 7

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Observation: Dermis 40X 100X 10 x 40 x Activity: Part C- Preparing and observing wet-mount slides of Human Cheek Cells We will observe our cheek cells as an example of squamous epithelial cells using Crystal violet stain. We will gently scrape the inside of our cheeks using toothpicks and use our own cells as a specimen. Method: 1. Obtain a clean glass slide and a coverslip. 2. Put a small drop of Methylene Blue stain on the slide. Use a tooth pick to transfer cheek cells to the stain solution. 3. Put a coverslip on the specimen. Use wipes to carefully remove excess culture from the edges of the coverslip. Note to Students: Use Appendix A to follow instructions on using a Microscope. Instructions for preparing a wet-mount slide are in Appendix B. 4. Observe the slide under 10X, 40X and 100X objective lenses as directed by your instructor. Don’t forget to use oil with 100X lens. Note to Students: Don’t forget to use oil with 100X lens only. After completing the observation, clean the oil immersion lens with lens paper to remove oil. Be careful to not contaminate other lenses (4X, 10X, 40X) with oil. BIOS251 Week 5 Lab Instructions Page 4 of 7

5. Record and describe your observations made using a low-power magnification (10x) and high- power magnification as directed by your instructor (40x or 100x). Make sure to note as many details as possible, and include the magnification used. Observation: Wet Mount of Human Cheek Cells 40X 100 X 10 x 40 x OBSERVATION REPORT: W5 Lab Worksheet Integument 1. List and describe the 3 main cell types of skin and include the cell types found in them. (2 points) A)Epidermis: -Keratinocytes: These cells are the predominant type fond in the epidermis and are responsible for synthesizing keratin, which contributes to the skins protective and water-resistant properties -Melanocytes: These cells produce the pigment melanin which gives the skin its color and provides protection of ultraviolent radiation Langerhans cells: Theses cells are part of the immune system and help protect against infectious diseases Merkel cells: These cells are involved in the sensation of touch B) Dermis: -Fibroblasts: These cells produce fibers and elastin fibers, which provide support and elasticity of the skin -Mast Cells: These cells are involved in the body’s inflammatory response by secreting histamines and other substances when there is damage or an allergic reaction -Macrophages: These are immune system cells that play a role in removing cellular waste and infectious agents from the skin BIOS251 Week 5 Lab Instructions Page 5 of 7

C) Hypodermis: Subcutaneous layer -Adipocytes: these are fat cells that store energy and provide insulation -Blood Vessels and nerve endings: These help transmit sensory information and help to regulate temperature 2. Draw an image of the three main layers of skin. Label the different labels and the structures in them. (4 points) 3. Compare the prepared (pre-made) slides of epithelium with the wet mount of your cheek cell images. What were the similarities and differences? (3 points) Similarities: -both samples may have been stained to make the cells look more visible -both prepared slides and wet mounts are used for microscopic observation of cells -both cells involve epithelial cells, even though the epithelial cells on the prepared slides may be from a different part of the body Differences: -the prepared slides show a larger possible choices of cell types, while the wet mount may only show the cheek cells -the prepared slides usually have a clear and high quality image, while the wet mount may be less clearand may require more observation BIOS251 Week 5 Lab Instructions Page 6 of 7

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4. Describe the types of cells found in connective tissues and provide examples of their functions. (3 points) Fibroblasts: cells that are responsible for producing collagen, elastin, and other fibers that give connective tissues their strength and elasticity Adipocytes: these cells are specialized in lipid storage, providing energy reserves and thermal insulation Mast cells: they secrete substances such as histamine that contribute to the body’s response to injury and allergies Macrophages: These cells are part of the immune system and function to consume and break down cells, pathogens, and unwanted particles. Chondrocytes: found within cartilage, these cells are responsible for maintaining the cartilage structure Osteocytes: these cells are integral to bone structure, involved in sustaining bone tissue. And play a role in managing the levels of calcium Blood cells: within connective tissue, blood cells house various blood cells including erythrocytes, leukocytes, and thrombocytes, which are all essential in transporting oxygen **LAB REPORT IS DUE PRIOR TO THE DUE DATE AS ASSIGNED BY YOUR PROFESSOR BIOS251 Week 5 Lab Instructions Page 7 of 7

BIOS251 W5 Lab Instructions(1)

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