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Histology Labs #11- Muscle & Nervous Tissue ID Lab Exercises

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

In this "Lab Exercise", we will be looking at some of the common Muscle & Nervous Tissue Slides. These tissues will be covered in more detail in other labs. This is only meant as an introduction to the tissues, in order compare them to Epithelial and Connective Tissues. Since these tissues are done in detail in later labs, instructors differ greatly in which muscle & nervous tissues they do at this early stage, as well as the detail that they are covered. Please check with your instructor! 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! Appendix 1 has a photo of the "Connective Tissue" wall chart. Use it to label. Appendix 2 has some sample slides, with some examples of "Descriptive Terms" from students in the past. Take a look at these. Use Appendix 2 after you have tried to come up with your own, as a way of comparing what you see with what others see. Try of see what they see. The Steps found in this "Lab Exercise Guide" should be done in the order they are found.

2 Step 1. Know what your instructor wants you to know about Muscle Tissue

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

Opening Paragraph (we'll be referring to this later)

These should be done using the wall chart, and any images in your lab or lecture book showing you muscle tissue. If another group is using the wall chart, use this image below:

Read me!

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Q1. There are 3 types of muscle tissues Where are they found? Write down a short list of where you might find these tissues, Including the role they plays. Concentrate on anything your instructor told you.

Skeletal Muscle - Cardiac Muscle - Smooth Muscle -

Q2. Name the cells of these tissues. Q3. ID the "other features" of these tissues and cells you need to know in lab Write the names of any other features you might need to know. Only include the features that your instructor wants you to know!! If the answer is "none", write that down!

4 Step 2. ID Muscle Tissues

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

Opening Paragraph (we'll be referring to this later)

Our group is on our own for looking at the muscle tissues. Hopefully, we have learned enough from looking at the other tissues using the guides to guide ourselves! We should follow these procedures for each of the muscle types:

1. Write down the cells you have to know on the slides. 2. Write down any other structures or features the instructor wants you to know. 3. If you will be examining the tissue under the scope, rind the slides needed. The next few pages will tell you that for each muscle type. 4. Understand which power is needed to ID the tissue best. That will also be on the next page for each muscle type. Check with the instructor's instructions, as they might want something different! 5. Get out as many microscopes as there are muscle tissue types. Put the slides on the microscope. Scan around until you see something similar to the images in the book, or on the wall chart. 6. TRY HARD to ID cells or other features at this power. Don't worry if you can't...we'll be zooming in to the power we need. 7. Zoom in! 8. Make a drawing! Note the power! Think of a descriptor term. 9. Look for similarities between how the slide looks, the images in the text, and the wall chart in the room! There is a copy of the "Muscle Tissue Wall Chart" in Appendix 1; make notes on it. Also look to see if there are some example descriptor term in Appendix 3.

Let's Go!

Read me!

5 #1 Skeletal Muscle:

Slide "Human White Fibrous - tendon" AND "Skeletal Muscle Tissue

NOTE: The tissue can be seen on slide marked "Skeletal Muscle Tissue" at 400X, but try the tendon slide first so we can compare 2 tissues (fibrous & skeletal muscle)!

Steps For This Slide: 1. First, re-examine the "fibrous" tissue on the slide (that is, Dense Regular Connective Tissue") at 40X, 100X, 400X. 2. Then, go back to low power. Find the Skeletal Muscle Tissue. Start at 40X, then go to 100X, but ID at 400X. 3. Follow all procedures in found in "Step 2: ID Muscle Tissues". Drawings & Notations. Try to compare Dense Regular & Skeletal Muscle:

Examples of Some Descriptive Terms for Some Tissues (some thoughts from past students)

Skeletal Muscle "railroad tracks from the air " "ladders" Skeletal Muscle Photo of railroad tracks from the air

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#2

Cardiac Muscle:

There are 2 different slides in the tray marked "Cardiac Tissue". One is from the company TURTOX. These have intercalated discs everywhere, but there are only 2 slides! The other is the company TRIACH. Here, the intercalated discs are only found near the edge of the stained area!

NOTE: The tissue can be seen on slide marked "Skeletal Muscle Tissue" at 400X, but try the tendon slide first so we can compare 2 tissues!

Steps For This Slide: 1. First, examine the slide at 40X, focus, go up to 100X, fine focus, re-examine the slide. 2. Move around at 100X, locating some intercalated discs. Go up to 400X. ID at 400X. 3. Follow all procedures in found in "Step 2: ID Muscle Tissues". Drawings & Notations. Try to compare Skeletal Muscle & Cardiac Muscle:

7 #3 Smooth Muscle:

Most instructors do not have students do a detailed microscopic exam of Smooth Muscle Tissue at this point. However, some do. It is YOUR responsibility to know if you need to look at the "Smooth muscle" slides. Here, we are only going to have you compare the Wall Chart image of skeletal, cardiac & smooth muscle. There is a copy of the wall chart in Appendix 1. 1. Follow all procedures in found in "Step 2: ID Muscle Tissues", EXCEPT those related to looking at the slides under the scope. 2. Go to the wall chart, or use Appendix 1. 3. Note the striations in Skeletal & Cardiac. Note the absence of striations in Smooth Muscle Tissue. 4. In the space below, draw all 3 cell types. You may use your text or lab book for help. Label nuclei. Draw several cells connected to each other for each muscle tissue: 5. On the next page is a set of directions for looking at the 3 muscle cell models. If you do this section, compare your drawings to the models. Did you catch everything?

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#4 Tissues that resemble other tissues

"The Difficult Four"

In all of the histology that we have covered, there are only 4 tissue types that look similar: Skeletal Muscle and Cardiac Muscle look like each other, and they look similar to Fibrous and Fibrocartilage.

Here is a past student's comments:

"Skeletal Muscle looks like Dense Regular, or fibrocartilage! But, it can be identified by noticing its striations, which look like "railroad tracks". Watch out for lacunae on fibrocartilage. Of course, the cardiac muscle is also striated, but it has intercalated disks!" I couldn't have said it better:

Dense Regular Fibrocartilage Skeletal Muscle Cardiac Muscle

Read me!

9 Q3. Look over that last page, and discuss it with your lab mates. This may be done outside of lab in order to save you time here! Draw these 4 tissues in the boxes below. Make notes describing how you are going to tell them apart on the exam!

10 #5 Compare the 3 muscle cell models:

Ask your instructor if you need to do this!

This may be done outside of lab in order to save you time here!

Below are photos of models showing the 3 muscle cell types. In each case, the image on the right is showing you the junction between the cell and a nerve. Decide which terms you need to know off the models, if any. Examine the models in lab, using the images below for labeling purposes. Start off by labeling the images (skeletal, cardiac & smooth), and indicate any structures your instructor wants you to know.

11 Step 3. Know what your instructor wants you to know about Muscle Tissue

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

Opening Paragraph (we'll be referring to this later)

These should be done using the wall chart, and any images in your lab or lecture book showing you nervous tissue. If another group is using the wall chart, you can get by with the image below:

Read me!

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Q4. There are many types of nervous tissues. First, write down which you need to know in this lab (motor neuron, glial cells, etc.) Next to each tissue you identify below, write where are they found? Write down a short list of where you might find these tissues, Including the role they plays. Concentrate on anything your instructor told you.

Q5. Name the cells of these tissues that your instructor wants you to know. Q6. ID the "other features" of these tissues and cells you need to know in lab. Write the names of any other features you might need to know. Only include the features that your instructor wants you to know!!

If the answer is "none", write that down!

13 Step 4. ID Nervous Tissues

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

Opening Paragraph (we'll be referring to this later)

Since these tissues are done in detail in later labs, instructors differ greatly in which nervous tissues they do at this early stage, as well as the detail that they are covered. Please check with the instructor! In this guide, we will only deal with the basic identification of "Motor Neurons". Any other work the instructor wants should be done on another piece of paper. We should follow these procedures for each of the nervous types our instructor wants us to be familiar with:

1. Write down the cells you have to know on the slides. 2. Write down any other structures or features the instructor wants you to know. 3. If you will be examining the tissue under the scope, rind the slides needed. The next few pages will tell you that for each nervous tissue type. 4. Understand which power is needed to ID the tissue best. That will also be on the next page for each muscle type. Check with the instructor's instructions, as they might want something different! 5. Get out as many microscopes as there are muscle tissue types. Put the slides on the microscope. Scan around until you see something similar to the images in the book, or on the wall chart. 6. TRY HARD to ID cells or other features at this power. Don't worry if you can't...we'll be zooming in to the power we need. 7. Zoom in! 8. Make a drawing! Note the power! Think of a descriptor term. 9. Look for similarities between how the slide looks, the images in the text, and the wall chart in the room! There is a copy of the "Nervous Tissue Wall Chart" in Appendix 2; make notes on it. Also look to see if there are some example descriptor term in Appendix 3.

Let's Go!

Read me!

14 #1 Motor Neuron:

Slide "Ox Spinal Cord Nerve Cells"

NOTE: Motor neurons can be seen on other slides. Depending on their availability, there may be another slide tray present. We will be examining this slide at 100X

Steps For This Slide: 1. First, examine the slide at 40X, focus, move slide around until some small motor neurons come into view. Fine focus, and re-examine the slide. 2. Move up to 100X, locating motor neurons. 3. Follow all procedures found in "Step 4: ID Nervous Tissues".

Drawings & Notations.

Neurons "octopusses" Author's Note: I know that the plural of octopus is "octopi", but that's what the student wrote! Neural Tissue showing Neuron Drawing of an octopus

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#2 Look at the Motor Neuron Model:

Ask your instructor if you need to do this! Below is a photo of a motor neuron model. The exact model in lab may be different. Decide which terms you need to know off the model. Examine the model in lab, using the image below for labeling: