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Histology Labs Guide #5 - Epithelial Tissue ID: Squamous Tissue Lab Exercises

Have someone in your group read the following out loud, while the others read along:

In this "Walk About", we will be looking at squamous tissue YOU WILL NEED THE IMAGES IN YOUR TEXTBOOK! Our lecture book has an excellent section on the tissues, including summary tables. Of course, there are usually extra textbooks in lab, but there are not enough for everyone! PLEASE NOTE: Your group will be needing a microscope at the workstation. All of the steps in this guide are designed to be done at the workstation. DO NOT use a microscope that is already set up in the room, being used as a demo. Instead, get a new one from the microscope storage, get out a power cord, plug the cord into the microscope, and use the microscope at your station! This guide will assume that you have already done any readings, or watched any videos, your instructor has required. If you haven't, you'd better do that before going through this guide! The Steps found in this "Walk About Guide" should be done in the order they are found.

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Step 1. ID Simple Squamous Tissues

Have someone in your group read the following out loud, while the others read along:

Follow the numbered steps, answering questions along the way: First, let's find the "Simple Squamous" table in either our lecture or lab book. Look a the image in your book. Find where they indicate the cell you should be looking for.

Q1. Draw one in the box, noting the nucleus:

There are several slide trays in the room. Each tray has a different set of slides. Go and get a slide from the Simple Squamous trays. The slide will be marked "LUNG".

Now, we are going to put it in the microscope. Make sure your scope is on low power (40x). Now, following the numbered instructions below (1-

3), look in the eyepiece.

Q2. On the microscope (not the photo), can you see a cell? A nucleus? Can you see cell shape?

REALLY TRY!!! But answer honestly:

YES NO Not Sure

Something else ... Ignore It!

Move around until you see something like this.

Look at a similar region as this on the slide!

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3.

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Now, we will zoom in. Find something that looks like the insert photo below (labeled 100X):

Q3. On the microscope (not the above photo), can you see a cell? A nucleus? Can you see cell shape?

REALLY TRY!!! But answer honestly:

YES NO Not Sure Better than before

100X

40X

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Now, we will zoom in further. Find something that looks like the lower photo at 400X:

Q4. On the microscope (not the above photo), can you see a cell? A nucleus? Can you see cell shape?

REALLY TRY!!!

YES NO (If your answer is still "no", look at APPENDIX 1 and ask your instructor for help)

Q5. On the microscope (not the above photo), go back to LOW POWER. Now can you see cells, nuclei, and cell shape at this low power?

100X

400X

5 #7 You may be tested on this tissue at 100X or 400X.

Q6. Go up to 100X (middle power). Draw what you see in the box on the left. Label the lumen (if more than 1, label them all), cells, and their nuclei. Write the power and a descriptor term below. Then go to 400X (high power). Do the same on the right.

Power:

Descriptor Term: Q7. Write down some representative locations for this tissue. If your instructor mentioned any, make sure you write them down! Q8. Write down any extra information your instructor wants you to know. If the answer is "none", just write that! Q9. Talk about this phrase with your lab mates:

"The truth is, unless we'd seen a lung slide before, the correct answer to Q#2 was 'not sure'. If we had said 'yes', even if we turned out to be right...how did we know?" "And if we said 'no' on Q2: how did we know?"

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#8 In the lab room, there is a Wall Chart labeled "Epithelial Tissues", with 2 examples of Simple Squamous Tissue (there is a copy below). Go look at the chart if it is available.

The first photo (extreme upper left of chart) looks VERY different than what we just saw with the lung. See the photo to the right.

Q10. Explain why it looks so different:

CClloossee uupp vviieeww

7 The second photo ( upper middle of chart) looks VERY different than what we just saw with the lung. See the photo to the right. This image is taken from a blood vessel. The problem is: you don't know what a blood vessel looks at low power. Look at the photo of a blood vessel slide below. Follow the steps (1-3):

Q10. Outline 1 simple squamous cell on the image of the wall chart above. Q11. Which of these phrases describes the difference between the "wall chart" image, and the photo in Step 3 above? The wall chart image is:

In better focus at higher power at lower power

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8 #9 ONLY DO THIS STEP if you are still having problems.

If you are having problems getting your eye to see the cells on a lung slide, call your instructor over and go through the following image. It is not necessary to follow along on a microscope, but you may try it. This image uses a step higher in magnification than we saw earlier. This is an "oil immersion lens". You will need help using this lens if you try to follow these steps on a microscope.

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Step 2. ID Stratified Squamous Tissues

Have someone in your group read the following out loud, while the others read along:

Follow the numbered steps, answering questions along the way:

First, let's find the "Stratified Squamous" table in either our lecture or lab book.

Look a the image in your book. Find where they indicate the cell you should be looking for. (HINT: it is the same cell as we saw in STEP #1).

Q12. Draw one in the box, noting the nucleus:

There are several slide trays in the room. Each tray has a different set of slides. Go and get a slide from the Stratified Squamous trays. The slide will be marked "ESOPHAGUS".

Now, we are going to put it in the microscope. Make sure your scope is on low power (40x). Now, look in the eyepiece. Find something like the image below.

Q13. Label the lumen on the photo. . Q14. On the microscope (not the photo), can you see a cell? A nucleus? Can you see cell shape?

REALLY TRY!!! But answer honestly:

YES NO Not Sure

Move around until you see something like this. Look at this on the slide!

1. 2.

10 #5 Now, we will zoom in. Find something that looks like the lower photo at 100X:

Q15. On the microscope (not the above photo), can you see a cell? A nucleus? Can you see cell shape?

REALLY TRY!!! But answer honestly:

YES NO Not Sure Better than before

Keep your eye on the lumen

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Now, we will zoom in further. Find something that looks like the lower photo at 400X:

Q16. On the microscope (not the above photo), can you see a cell? A nucleus? Can you see cell shape?

REALLY TRY!!!

YES NO

(If your answer is still "no", ask your instructor for help) Q17. On the microscope (not the above photo), now go back to LOW POWER. Now can you see cells, nuclei, and cell shape at this low power?

Keep your eye on the lumen

12 #7 You may be tested on this tissue at 100X or 400X. Q18. Go up to 100X (middle power). Draw what you see in the box on the left. Label the lumen (if more than 1, label them all), cells, and their nuclei. Write the power and a descriptor term below. Then go to 400X (high power). Do the same on the right.

Power:

Descriptor Term:

Q19. Write down some representative locations for this tissue. If your instructor mentioned any, make sure you write them down! Q20. Write down any extra information your instructor wants you to know. If the answer is "none", just write that!

Q21. Talk about this phrase with your lab mates:

"The truth is, unless we'd seen a stratified squamous slide before, the correct answer to Q#11 was 'not sure'. If we had said 'yes', even if we turned out to be right...how did we know?" "And if we said 'no' on Q11: how did we know?"

13 #8 In the lab room, there is a Wall Chart labeled "Epithelial Tissues", with an example of

Stratified Squamous Tissue (see Appendix 2). Go look at the chart if it is available. There is also a photo in your book.

Q22. On the image of the wall chart to the right, draw an arrow pointing to the lumen Q23. Do the 3 look similar (book image, wall chart photo, and slide)? If you need to, draw them in the space below. Point out any SIMILARITIES.