ZOO 2090 Lecture Notes - Lecture 10: Longissimus, Cranial Nerves, Electric Eel
Document Summary
Classify muscles according to commonly used criteria. Highlight the function of major muscle groups in vertebrates. By method of nervous control (voluntary or involuntary) By microscopic appearance (smooth, cardiac or skeletal: skeletal muscle associated with skeleton, cardiac muscle of heart wall, smooth muscle of blood vessels and many visceral organs. Differentiation into segmented somites (epimere), hypomere and mesenchyme. October 16, 2013 somites are divided further into dermatome (skin), myotome (muscle) and sclerotome (vertebral column: somites anterior mesoderm clusters do not become fully segmented fate of mesoderm divisions, 1) myotome divisions of somites. Most postcranial and some cranial muscles: 2) somitomeres. Muscles of gut and heart: 4) mesenchyme. Usually two groups of muscles working opposite to each other flexors/extensors bend/straighten a limb or a part of a limb. Abductors/adductors draw a limb away or toward the midline of the body. Pronators/supinators turn palm or sole down/up. Protracts/retractors levators/depressors raise/lift or lower constrictors/dilators close/open orfices.