Worksheet on Skeletal Muscle 1) Label the structures of a skeletal muscle. Please note that some of the labels are pointing to the same structure. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 2) Identify the structures of the muscle fibre below by using the words provided. You may write the whole word or just the letter. Just click on a box to add text – be carefully not to move the image or the whole thing goes wonky. A B C D E F G H I 3) Match the descriptions with the correct muscle fibre structure. Use the words above in question 2 and put the letter on the line next to the matching description. (Not all words will be used) i. ii. iii. iv. v. vi. Composed of a T-tubule, the terminal cisternae, and gaps……… Cylindrical structures that carry out contraction………. Extensions of the sarcolemma that separate the sarcomeres……… Specialized plasma membrane of the skeletal muscle cell; forms membrane connections between each of the sarcomeres………. The specialized endoplasmic reticulum of the skeletal muscle cell……….. Units of the myofibrils……… 4) a) b) c) d) e) f) g) h) i) j) k) 5) Identify the parts of the sarcomere below by using the words provided. You may write the whole word or just the letter. A B C D 6) Match the descriptions with the correct sarcomere part. Use the words above, and put the letter on the line next to the matching description. (Not all words will be used) i. The bands that mark the sarcomere’s borders ii. The bands that mark the middle of the sarcomere iii. Under a micrograph, they are the lightest and least dense structures; composed of actin, troponin, tropomyosin iv. Much more dense than thin filaments; composed of myosin 7) The distance between the ends of the thin filaments was known as . 8) The distance between the thick filaments of one sarcomere and the thick filaments of an adjacent sarcomere was known as the . 9) The length of the thick filaments was known as the 10) Identify the areas in the following picture below 1 1 . 2 2 3 3 11) The and shortens, but the does not shorten during muscle contraction.