Department of Histology and Embryology Faculty of Medicine, PU, Olomouc, CZ

Histology practical No. 7 Topics: 1- STRUCTURAL AND FUNCTIONAL CHARACTERISTICS OF THE SKELETAL, SMOOTH AND CARDIAC MUSCLES. (Pre-lab rev.ppt).

2- RECOGNITION OF THE SKELETAL, SMOOTH AND CARDIAC MUSCLE IN STAINED HISTOLOGY AND PC-MONITORED SLIDES OR PRINTED IMAGES.

3- UNDERSTANDING THE ULTRASTRUCTURAL BASIS OF MUSCLE CONTRACTION - THE SARCOMERE.

4- RECOGNITION OF IMPORTANT ULTRASTRUCTURAL FEATURES OF SKELETAL, CARDIAC ABD SMOOTH MUSCLE IN

PC-MONITORED SLIDES OR PRINTED EM IMAGES. Slides:

1. Skeletal muscle (sval příčně pruhovaný, sl.n. 81) l.s., H&E stain.

This slide contains longitudinal sections of many skeletal muscle fibers. Find a group of straight-running skeletal muscle fibers that show many nuclei located under their sarcolemma. Identify the striations (arrow) and using the high power lens, locate the I and A bands. What kind of proteins are responsible for these striations?

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2. Tongue, skeletal muscle, (hrot jazyka, sl.n. 81) l.s., H&E stain.

This slide shows a tip of the tongue where the skeletal muscle fibers run in various directions. Compare the longitudinal sections of skeletal muscle (l.s.) with transversal ones (arrow). Note that in transverse sections the striations are not visible. What other feature helps you to indentify these transverse sections as a skeletal muscle? In your spare time, you can revise the lining epithelium and some connective tissue structures. l.s.

3. Cardiac muscle (myokard, Harris&eosin., sl.n. 1), l.s., H&E stain.

This section of the heart wall shows the cardiac muscle cells (cardiomyocytes) mostly in longitudinal sections. Find the best area where you can observe bundles of cardiac muscle cells running in one direction. Note the branching shape of cardiomyocytes (arrow), look for striations of myofibrils, evaluate central position of nuclei in cells and locate the intercalated discs that separate individual cells in bundles. Revise the ultra-structure of the intercalated disc. What makes the difference between the skeletal and cardiac muscle cut in transverse section?

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4. Smooth muscle (hladká svalovina, sl.n. 82), section, H&E stain.

This is a transverse section of an appendix without a clear cut lumen. Find the pink-stained peripheral zone of smooth muscle cells that are shown there in both, longitudinal sections (the inner sub-layer, l.s.) and transverse sections (the outer sub-layer, arrow). Locate the individual smooth muscle cells, note the absence of striations, find the elongated fusiform nuclei in t.s. layer and confirm the central position of nuclei in l.s. layer. Why some of the cells in t.s. layer do not contain nuclei?

l.s.

5. Smooth muscle, uterus (děloha, sl.n. 49) sect., H&E stain.

Uterus has a lot of smooth muscle cells in its wall. Under the superficial epithelial layer (mucosa), find the layer of the smooth muscle cells that are in bundles oriented in all directions (arrows). Compare some longitudinal and transverse sections of smooth muscle cells and note the very elongated shapes of their nuclei.

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6. Esophagus (jícen příčně, sl.n. 22) t.s., H&E stain.

In the upper part of the esophagus, there are layers of skeletal muscle (Sk.M.) and smooth muscle (arrow) next to each other for easy comparison. Find the two kinds of muscular tissue and note the difference between them. Write down in your lab. notes the most striking differences that help to differentiate these two kinds of muscle tissue.

Sk.M.

7. Study the electron micrographs that circulate during the practical session to revise the ultrastructure of skeletal muscle and smooth muscle.

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SMOOTH MUSCLE CELLS

9. In your selfstudy, revise the ultrastructure of skeletal muscle, smooth muscle and cardiac muscle cells. (Use the recommended textbook, atlas with CD-ROM and WWW)

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Identify this picture: ………………………….. Identify this picture: ………………………

In the above picture, identify the whole structure and name the labels there. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Websites: http://www.histology-world.com/audioslides/cardiac.htm http://www.histology-world.com/audioslides/skeletalmuscle1.htm http://www.anatomyatlases.org/MicroscopicAnatomy/Section05/Section05.shtml http://www.youtube.com/watch?v=WFQLFHbMMaM http://www.youtube.com/watch?v=1ExGP33Be4M&feature=PlayList&p=941DC2E7793A3815&playnext=1&playnext_from=PL&index=9 http://www.youtube.com/watch?v=HcWX-b07qqM&feature=related http://www.youtube.com/watch?v=WRxsOMenNQM&feature=related http://www.youtube.com/watch?v=VQ4OMSi6qAg&feature=related http://www.youtube.com/watch?v=InIha7bCTjM&feature=related http://www.youtube.com/watch?v=MoyQjFncPQw&feature=related http://www.youtube.com/watch?v=ZscXOvDgCmQ&feature=related http://www.youtube.com/watch?v=PJDrR3sZPZU&feature=related 7-MusclePractical.doc dk-3/2009

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