Anatomy and Cell Biology 3319 Lecture : Anatomy Notes
20 Feb 2012
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Skeletal muscles consist of fascicles, which are bundles of nerve or muscle fibres bound together by connective tissue. In different muscles, the fascicles are aligned in different patterns. Circular muscles surround external body openings, which they close by contracting (ex. orbicularis oris). In convergent, the origin of the muscle is broad and the fascicles converge toward the tendon of insertion, creating triangle shape (ex. pectoralis major). In parallel, the fascicles run parallel to the muscle. Parallel muscles can be fusiform (tapered ends, ex. biceps brachii) or strap-like (ex. sternocleidomastoid). In pennate pattern, the fascicles are short and attach obliquely to a tendon that runs the whole length of the muscle. Muscle attachments: origin immovable, static part of movement. A muscle that crosses on the anterior side of a joint produces flexion and one that crosses on the posterior side produces extension.
