BIOL&241: Lab 6 Part 1 Lab 6- Activity 1- Examining Epithelial Tissue Under the Microscope (Note- there is a separate handout for Lab 6A, Activity 2- Connective Tissue). This handout should serve to clarify what types of epithelia to look at, what sketches to hand in, and what to label in your sketches. Remember, to include a title of each sketch, and the total magnification. You MUST LABEL the important features of your sketches! You will also want to indicate the TYPE of epithelia (if its not stated in your sketch title). Slides 6A-6D are simple epithelia. 6A. Look at and sketch simple squamous epithelium. To do this, you should look at the slides labeled, either: “adipose tissue” or “artery, vein, capillary” (also adipose tissue). We are using adipose tissue (fat), because it is rich in blood vessels. A. Try to find a very, very small blood vessel, a capillary. B. In your sketch, label: the nucleus of a simple squamous cell, the lumen of the capillary, and any visible blood cells. You may want to include a bit of the surrounding adipose tissue in your sketch. (NOTE- the figure on p70 is NOT adipose tissue!) You may want to look at the capillary cartoon on page 699 of your text, or an arteriole on page 698. 6B. Look at and sketch simple cuboidal epithelium. Here you will be looking at kidney epithelia. You are looking for kidney tubules (parts of nephrons). There are many to see. Tubules are highly coiled, and thus you may see tubules that have been sliced in transverse section (cross section) or in longitudinal section (along the length of the tubule). A. Clearly indicate the tubule itself, the tubule lumen, at least two cuboidal cells, and label each cell’s nucleus. B. Indicate the apical and basal region of one cuboidal cell. 6C. Look at and sketch simple columnar epithelium. You will again be looking at kidney epithelia. Some of the tubules are made up of a single layer of columnar epithelia. Try to find one! A. In your sketch, label: the lumen, the tubule itself, a single cell, and that cell’s nucleus. B. Also, indicate on this cell the apical region, and where the basal region is found. 6D. Look at and sketch simple columnar epithelium with goblet cells. This is a slide of the intestinal wall. The epithelium here is highly folded, or has ridges that go up and down. This tissue also has numerous glands (that typically stain a different color than the columnar cells). Goblet cells are found scattered among the epithelial lining of the intestines. A. In your sketch, label: the lumen, a simple columnar epithelial cell, a goblet cell, and the basal lamina. B. Can you see the vesicles inside the goblet cell? Slides 6E-6F are epithelia with ‘funky’ arrangement. 6E. Look at and sketch pseudostratified ciliated columnar epithelium. This epithelium is found lining much of the upper respiratory tract. A. In your sketch, label: the lumen, the basal lamina, & indicate where you see cilia. B. Do all of these columnar cells touch the basal lamina? 6F. Look at and sketch transitional epithelium. This epithelium lines organs that need to stretch (like the bladder). A. Do all of these cells touch the basal lamina? B. Do you think that this particular slide shows a relaxed or stretched organ? Why? Slides 6G-6H are of stratified epithelium. 6G. Look at and sketch stratified squamous epithelium. A. Label: the region of the ‘strata’ (stack) where you would expect to find cells undergoing mitosis, the region of the ‘strata’ where you would be likely to find dead cells, label the basal lamina, and indicate where the underlying connective tissue is. 6H. Please venture to the web to look at and sketch stratified columnar epithelia. A. Label the lumen. Label two, stacked cells and their nuclei. Notice that the bottom cell may not appear columnar at all. In fact, we look at the shape of the TOP cell to classify epithelia! B. Links to stratified columnar: http://www.cytochemistry.net/microanatomy/epithelia/stratified_columnar.htm http://www.mhhe.com/biosci/ap/histology_mh/strcol2.jpg GENERAL LINKS FOR EPITHELIA A few good links for epithelia are listed here. If you so not have time to complete your sketches of the epithelia, consider using images from these links to sketch from, BUT BE SURE TO INCLUDE a reference with your sketch, and an estimate of total magnification!! http://www.bu.edu/histology/m/t_epithe.htm http://science.tjc.edu/images/histology/Index.htm http://www.unomaha.edu/hpa/2740epithelium.html#col Adapted from H. Iverson