Lab 3 Epithelial Tissue PDF

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Summary

Lab for understanding types of epithelial tissue...

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3.1 LAB 3: EPITHELIAL TISSUE Epithelial tissue covers body surfaces; lines hollow organs, body cavities and ducts: and forms glands. Epithelial cells are arranged in continuous sheets, in either single or multiple layers. The main objective for this lab is to learn the structure and functional relationships of epithelial tissues. You will be viewing slides for identification of tissue, as well as structures associated with the tissue. Use the following table to guide you through the tissues. Please note- there may be more than one type of tissue on the slide. You need to make sure you know what you are looking at. Use your guide, text and following worksheet to assist you. OBJECTIVES:   

To identify epithelial tissue types and specific structures under the microscope. To know where these tissues may be found in the body. To know the functions of the types of epithelial tissue.

MATERIALS:    I.

Prepared slides Images in Moodle Visible Body -The Tissue Level of Organization: 4.1-4.5

EPITHELIAL TISSUE (Epithelium) General Information: 

Epithelium is located all around the body, especially covering and lining organs.

EXAMPLE: outer layer of skin, lining body cavities, lining glands and blood vessels 

Characteristics



a. avascular (lack blood vessels) b. can regenerate c. help to produce a basement membrane d. sandwiched between a lumen and basement membrane e. often have specialized cell junctions ~ ex: spot desmosomes Epithelial tissue is generally named based on a. b.

the shape of the cells found in the tissue the general organization or layering of these cells Shapes: 1) 2) 3)

squamous - squashed or flattened cuboidal - cubed shaped with large central nucleus columnar - long and rectangular with nucleus located in the bottom 1/3 of the cell

Organization: 1) 2) 3) 

simple - one cell layer thick stratified - multilayered, only bottom layer touches basement membrane pseudostratified - looks layered ... but all cells touch basement membrane

Cell Associations: In epithelial tissue there are other additions to the tissue layer besides shape and layering. 1) 2) 3)

Goblet cells - mucous-producing cells Cilia - hair-like projections on the outer surface Microvilli - finger-like projections on the outer surface

Table 3.1 Tissue Types Tissue Simple Squamous Epithelium 



Single layer of flattened cells with a central nuclei Allows for diffusion and filtration of materials.

Simple Cuboidal Epithelium 

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Organ/ Slide Name Kidney

Single layer of cube-like cells with a central nuclei Functions in secretion and absorption.

Kidney

Tissues found on the slide.

3.2

Simple Columnar Epithelium Without goblet cells

Intestine

Column shaped cells with nuclei near the basal side of the cell.  May contain additional structures such as cilia, microvilli  Functions in absorption and secretion Simple Columnar Intestine Epithelium With goblet cells 

  

Column shaped cells Contains goblet sells and microvilli Functions in absorption and secretion of mucus

Psudostratified Eptithelium 



 

Single layer of cells of varying heights. All cells reach the basement membrane. May contain goblet cells and cilia Functions in secretion and movement of materials by the cilia

Trachea

Stratified Squamous Epithelium  

 

Esophagus – Nonkeratinized

Several layers of cells Basal cells are cuboidal or columnar. As the cells migrate toward the lumen they become flattened squamous cells. Non keratinized or Keratinized keratinized Functions in producing membranes for protection

http://www.mhhe.com/biosci/ap/histology_mh/stratepi.html

Name:

Assignment Simple Squamous Epithelium 1. Get a slide labeled Kidney or Simple Squamous Tissue. 2. Open Visible Body to 4.4-Simple Epithelium and click on the second circle under the picture. This is a magnified image of a kidney glomerulus. Using this image and the one from table 3.1 as a guide, locate simple squamous tissue on the slide under the microscope. 3. Once you have located the tissue draw what you see under the microscope. 4. Once you have located the tissue, in the circle below draw what you see under the microscope, label and answer the questions.

1. Where in the body, other than the kidney, would you find simple squamous tissue? ________________________________________ ________________________________________ 2. Name two characteristics of this tissue. a) _________________________________ b) _________________________________ 400X Label: one squamous cell, a nucleus and the cell membrane. Note: you will have to draw in the cell membrane

Simple Cuboidal Epithelium 1. Get a slide labeled Kidney 2. Open Visible Body to 4.4-Simple Epithelium and click on the third circle under the picture. This is a magnified image of a kidney glomerulus. Using this image and the one from table 3.1 as a guide, locate simple cuboidal tissue on the slide under the microscope. 3. Once you have located the tissue, in the circle below draw what you see under the microscope, label and answer the questions. 1. Specifically where in the Kidney would you find simple cuboidal epithelium? _________________________________________

2. State one function of this tissue. 400X

Label: one cuboidal cell, nucleus and cell membrane

__________________________________

A-3.2 Simple Columnar Epithelium With Goblet Cells 1. Get a slide labeled Goblet Cell Epithelium 2. Open Visible Body to 4.4-Simple Epithelium and click on the fourth circle under the picture. This is a magnified image of the small intestine. Using this image and the one from table 3.1 as a guide, locate simple columnar tissue with goblet cells on the slide under the microscope. 3. Once you have located the tissue, in the circle below draw what you see under the microscope, label and answer the questions.

1. Where would you find this tissue? ____________________________________ 2. Goblet cells produce and secrete mucus. What is the function of the mucus? ____________________________________ ____________________________________

400X Label: a goblet cell, a non-goblet cell, nucleus, lumen, apical surface, basal surface and cell membrane

Psudostratified Epithelium 1. Get a slide labeled Trachea and Esophagus: You will be looking at the trachea. 2. Open Visible Body to 4.4-Simple Epithelium and click on the fifth circle under the picture. This is a magnified image of the trachea. Using this image and the one from table 3.1 as a guide, locate psudostratified tissue on the slide under the microscope. 3. Once you have located the tissue, in the circle below draw what you see under the microscope, label and answer the questions.

1. Would you find this tissue in the nasal cavity? ______________________________________

400X Label: a psudeostratified cell, basement membrane, lumen, nucleus, cilia

2. This tissue almost always has cilia. What is the purpose of having cilia in the trachea? ______________________________________

A-3.3

Stratified Squamous – Nonkeratinized 1. Get a slide labeled Trachea and Esophagus: You will be looking at the esophagus. 2. Open Visible Body to 4.5-Stratified Epithelium and click on the first circle under the picture. This is a magnified image of the epidermis of the skin. Using this image and the one from table 3.1 as a guide, locate stratified squamous tissue on the slide under the microscope. 3. Once you have located the tissue, in the circle below draw what you see under the microscope, label and answer the questions.

1a. Why would you find non keratinized stratified epithelium in the esophagus? 400X Label: one squamous cell, nucleus, cell membrane

_________________________________

2. What substance makes squamous cells keratinized ___________________________________

Stratified Squamous- Keratinized 1. Go to the following web page: https://www.austincc.edu/histologyhelp/tiss ues/tg_stra_sq_ker_e.html 2. Review all three images (40X, 10X and 400X) 3. Draw and label the third image (400x). 4. Answer the questions

Label: one squamous cell, nucleus, cell membrane

______________________________

3. . Name one benefit of cells being keratinized ___________________________________ ___________________________________...