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Muscles  Muscles have 3 types: Skeletal Cardiac Smooth fibers Longitudinal Branched longitudinal and with Spindle shaped pa...

Muscles  Muscles have 3 types: Skeletal Cardiac Smooth fibers Longitudinal Branched longitudinal and with Spindle shaped parallel intercalated discs striations longitudinal and longitudinal and No striations transverse transverse striations striations nucleus Multi nucleated One nucleus One nucleus Control Voluntary Involuntary Involuntary Site Attached to bone Heart = GIT, bl.vs, others myocardium Function Movement Pumping of According to site blood ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ 1 Muscles  Function of skeletal muscles : 1) They produce different movements of the body by their contractions, which approximate the bones of the skeleton on which they are attached. 2) Their contractions pump venous blood to the heart. 3) They share in the heat production of the body. 4) Maintain posture and body position.  Function of Smooth muscles:  Guard entrances and exits: a) They encircle openings to digestive and urinary tracts. b) Control swallowing defecation and urination. ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ 2 Muscles  The whole muscle is surrounded by epimysium.  The muscle is formed of bundles of muscle fibers called fascicles.  Each fascicle is:  formed of muscle fibers.  surrounded by perimysium.  The fibers separated from each other by endomysium.  Each fiber is:  a single cylindrical elongated multinucleated cell 10- 80 microns in diameter.  surrounded by plasma membrane (sarcolemma)  contains several hundreds myofibrils.  Each myofibril consisted of several filaments.  These filaments are made up of the contractile proteins of muscle (actin and myosin) 3 ‫‪Muscles‬‬ ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ ‫‪4‬‬ ‫‪Muscles‬‬ ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ ‫‪5‬‬ Muscles 1)  The fibers run parallel to each other.  They take different shapes: a) Flat like: e.g. platysma. b) Strap- like: e.g. Sartorius. c) Strap-like with tendinous insertions: e.g. rectus abdominis. d) Quadrate : e.g. pronator quadratus. e) Rhomboid : e.g. rhomboideus major. ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ 6 Muscles 7 Muscles 2) e.g. biceps brachii. 3) fibers converge into tendon e.g. Pectorais major. ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ 8 Muscles 4) the fibers are arranged into concentric rings e.g. orbicularis oris. 5)  The fibers run & atached obliquely to a longitudinal tendon.  They take the following shapes: a) Unipennate: resembling ½ of a feather e.g. extensor digitorum longus. b) Bipennate: resemble g a complete feather, e.g. rectus femoris. c) multipennate: resembling 3 o more feathers joined at their basis e.g Deltoid. ‫ﻣﻠﻔﺎت ورواﺑط اﻟدورة ﻣﻘﺗﺻرة ﻋﻠﻰ اﻟﻣﺷﺗرﻛﯾن ﻓﻘط وﻻ ﻧﺣﻠل اﺗﺧداﻣﮭﺎ ﺧﺎرج اﻟدورة‬ 9 Muscles 10