ZOO 2090 Lecture Notes - Lecture 9: Electric Eel, Skeletal Muscle, Stapes

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2090
• Professor: Jinzhong Fu

Document Summary

Collection of modi ed cells that can generate force along the axis of their bres ! contractile. Force can be used to produce movement or restrain movement. In order to do that, muscle cells are electrically excitable responsive to nervous stimulation. Some muscles are modi ed to generate electric shocks (e. g. , electric eel) or electric elds (e. g. , electrosensory. Classification: by location (somatic and visceral, by method of nervous control (voluntary or involuntary, by microscopic appearance (skeletal, cardiac or smooth) Classification: skeletal muscle ! associated with the skeleton, cardiac ! muscle of the heart wall, smooth ! muscles of blood vessels and many visceral organs. All muscles originate from mesoderm differentiation into segmented somites (epimere), hypomere and mesenchyme somites are divided further into dermatome (skin), myotome (muscle) and sclerotome (vertebral column) Somitomeres ! anterior mesoderm clusters do not become fully segmented. Muscle homology is often established based on nerve innervation.