A&P 1 Histology Labs #12 - Post-Lab Exercises: Putting Connective, Muscle and Nervous Tissues In Context: Re-visit Tissue Layers

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1 1 A&P 1 Histology Labs #12 - Post-Lab Exercises: Putting Connective, Muscle and Nervous Tissues In Context: Re-visit Tissue Layers Have someone in your group read the following out loud, while the others read along: In this "Walk About", we will be looking at tissue layers. This will help the student put everything he or she is learning about tissues in context. 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! The Steps found in this first "Walk About Guide" should be done in the order they are found.

2 2 Step 1. Putting tissues in context. This may be done later to save time in lab! #1 Have someone in your group read the following out loud, while the others read along: Opening Paragraph (WE WILL BE REFERING TO THIS LATER): Remember our 'Visceral organ'?. It usually refers to the abdominopelvic and thoracic organs involved in Digestion, Reproduction, Respiration, Excretion. As a substance is moved through the tube, the tube either extracts stuff from the tube (absorption), or it puts substances into the tube (secretion, or excretion. Surrounding the lumen are 'tissue layers', which are a collection of tissues, with a specific task. Not all visceral organs have these 4, but they are common. We'll see them in a lot of organs. Layers: LUMEN Remember that all the layers may exhibit all the tissue types; here, we are looking for overall trends! Connective tissues are easily seen visually in the submucosa and the serosa. They are found in other places as well! In the submucosa, they are connecting and supporting in several ways. Something we'll see often is loose connective tissues supporting other tissues by storing water and nutrients, adipose, and immune cells. There are usually blood vessels in this layer, containing blood. If we need a little more support, we might see some dense connective tissue, also. In the serosa, the dense connective tissues, especially "dense irregular", will be surrounding the organ. forming an "outer protective coat" for the organ, and helping to connect the organ to the body. We'll also often see some adipose, which forma a nice protective cushion.

3 3 The other 2 main category of tissues, muscle and nervous, will be found in several places, most notably the muscularis layer! Why we find muscle tissue there should be obvious. Nervous tissue controls muscular movements through the tube! #2 Now answer the following questions: Q1. In your own words, talk to your lab mates about the difference between a "tissue" and a "tissue layer"? Which can be thought of as a "mini-organ"? (HINT: we answered this question in an earlier "Walk-About"!) Q2. Of course, connective tissues are found throughout the organ. But, according to what you read in the "Opening Paragraph", where is it easy to find connective tissues in many visceral organs? Label them on the image below

4 4 Q3. Of course, connective tissues are found throughout the organ. But, according to what you read in the "Opening Paragraph", where might you most likely find these connective tissues? On the photo, indicate where we might find the following, by placing the number in the correct layer: 1. Blood in blood vessels 2. Areolar and adipose providing nutrients and immunity 3. Dense Irregular forming a protective coat 4. Adipose protecting the organ from rubbing against other organs

5 #3 Something that is made of cartilage is called "cartilaginous". On the image below, "Step 1" looks closely at the trachea on a torso model, such as the one in lab. "Step 2" shows what a tissue slide would look like from a real trachea. 5 Q4. Look at the cartilaginous rings of the trachea on the close-up photo of the model. Then look at the photo of the slide. Can you label the following on the slide, drawing boundaries on the image? Lumen of the trachea Mucosal layer Submucosa with glands Hyaline cartilage ring