Anatomy Book SVNU-23-29 PDF

Forms of the skeletal muscles: Accordlng to the arrangement of muscle fibers 1- Parallel form: the muscle fibers run parallel to the axis of force generation. this includes varleties a- Fusiform: muscle that has a wide center and tapered ends (e.g. biceps brachii). b- Strap: long. flat muscle fibe...

Forms of the skeletal muscles: Accordlng to the arrangement of muscle fibers 1- Parallel form: the muscle fibers run parallel to the axis of force generation. this includes varleties a- Fusiform: muscle that has a wide center and tapered ends (e.g. biceps brachii). b- Strap: long. flat muscle fibers are parallel from origin to insertion (e.g. sartorius). c Convergent (triangular or fan-shaped): muscle fibers are fanned out broadly at the origin and converge at its insertion (e.g. pectoralis major). d- Circular muscle: in which the fibers are longitudinally arranged, but create a circle from origin to insertion (e.g. the orbicularis oculi). 2- Pennate form: in which the muscle has a feathered appearance where the muscle fibers run obliquely to the line of pull. Varieties are; Unipennate: the tendon lies along one side of the musce,and the muscle fibers pass obliquely to it (e.g., extensor digitorum longus), b- Bipennate: the tendon lies in the center of the muscle,and the muscle fibers pass to it from twosides (e.g., rectus femoris). c- Multipennate: It is as a series of bipennate muscles lying alongside one another (e.g., the deltoid). d- Circumpennate: Muscles have the tendon lying within its center and the muscle fibers passing to it from all sides, converging as they go (e.g., tibialis anterior). Skeletal Muscle Action All movements are the result of the coordinated action of many muscles. Muscle contraction that produces movements can act in several ways: 1- Agonist (prime mover): Amuscle is an agonist (prime mover) when it is the chief muscle or member of a chief group of muscles responsible for producing a particular movement. 2- Antagonist: Itthe muscle that opposes the action of the agonist muscle. 3- Fixator: A fixator muscle contracts to stabilize the origin of the prime mover so that it can act efficiently. 4- Synergist: It may directly or indirectly assist a prime mover during movement. I|-Cardiac muscle Cardiac muscle consists of involuntary partially striated muscle fibers that branch and unite with each other. It forms the myocardium of the heart. Its fibers tend to be arranged in whorls and spirals, and they have the property of spontaneous and rhythmic contraction. Specialized cardiac muscle fibers form the conducting system 22  Right Right four The cells. and thebody's Blood The spindle-shaped the af following plasma. (1) (2) cardiovascular " " " Smooth nodes the chambers; heart ventricle: atrium: is tissues capillaries, The and The Inpropels In In propelling In heart. the storage the the is fluid a blood intoheart, of superior a The walls tubes muscle he tCardiac pulmonary receives righthollow elements: and the the digestive receives which organs the cells conducting blood connectivevenules,vessels then systemic system of contents the contents closelyof is and atrium, the muscular the a muscle carries returns platelets, pumps blood such system, the circulation inferior and that consists by non-striated deoxygenated right tissue circulation Cardiovascular System body system is blood veins. as the through arranged organ nutrients, to carry blood vessels. the III-Smooth Muscle supplied venae ventricle, peristaltic it (as Heart The white the that of and via from urinary mixes the in heart the tointo the the in involuntary 23 circulates bundles in by cavae. blood the oxygen, blood ureters), lumen. the pulmonary e th left blood, supply the bladder ingested autonomic middle through pulmonary contractions. right fromatrium, cells the or myocardium. and through including sheets. itvisceral waste the body and food provides trunkatrium mediastinum. the (WBCs), nerve and the systemic veins. circulation tissues; with It left products the the uterus. muscle is and and the present fibers The red arteries digestive pulmonarypumps ventricle. blood arteries, and circulation It for motive consists that is to blood in; to gas terminate it divided and cells consists juices power from reach arterioles, exchange of arteries. into via (RBCs) long, the the into the the and for in of  Left atrium: receives the Oxygenated blood from the lungs via pulmonary veins (a andleft pulmonary veins). veins: upper right and left, and lower right Left ventricle: receives the blood from the left atrium and pumps it into the systemic clrculatlon vla the aorta. chambers. The interatrial Two internal septa divide the heart into its four separates the right and left atria, whereas the interventricular septum separates the septum right and left ventricles. The heart has an apex, a base, 4 surfaces, and 4 borders. downwarde The apex: it is formed only by the left ventricle and is directed fonwards and to the left. Pulsations of the apex can be felt below nipple of the left breast, in the left sth intercostal space at the midclavicular line. Base: It is formed mainly by the left atrium and the back of the right atrium. It is directed backwards and to the right. It lies opposite the thoracic vertebrae (T6 T9). Aorta Superior -Ligamentum arteriosum vena cava Right -Left pulmonary artery pulmonary -Pulmonary trunk artery -Left atrium Right puimonary Left veins pulmonary veins -Left ventricle (Left border) Right atrium (Right border) Right ventricle lnterior vena cava Apex Sternocostal (anterior) view of the heart The surfaces: 1-Anterior (sternocostal) surface: It is directed forwards, upwards and to the left, related to sternum and ribs. 2-Diaphragmatic surface: It is directed downwards and slightly backwards related to the diaphragm. It is formed primarily by the left ventricle. 3-Right pulmonary surface: formed mainly by the right atrium. 4-Left pulmonary surface: formed mainly by the left ventricle. 2  The borders: the two atria, mainly the left. 1-Upper border: It is formed by by the right atrium. 2-Right border: It is formed only ventricle and the apical part of left ventricle. right -lower border: It is formed by the ventricle and partly by the left atrium. mainly by the left 4-Left border: It is formed Left recurrent laryngeal nerve Left common Arch of Ligamentum arteriosum carotid artery aorta Left subclavian artery Bifurcation of puimonary trunk Superior vena cava Right atrium Pulmonary veins Left atrium Left ventricle Inferior vena cava Coronary sinus Base of the heart Interventricular Aortic semilunar septum valve Tricuspid AV valve Bicuspid AV valve (mitral valve) Valve leaflet Valve leaflet Chordae tendineae Chordae tendineae Papillary muscle Papillary muscle -Trabeculae carneae Septomarginal trabecula (moderator band) Internal features of the heart There are 3 main sulci (grooves): Coronary (atrioventricular) and the anterior and posterior interventricular grooves (sulci) that course on the surfaces of the heart: they contain the major vessels of the heart and epicardial fat. 25  andThe Valves The of are The portion N.B. semilunar Aortic 4- 3-atriaright atria 2- 1- three Vessels The Blood The 5- 4- 3- 2- 1- the Conducting 3. 2. 1. Pulmonary MitralTricuspid responsible conducting conducting when side > > blood Atrioventricular Atrioventricular The The Sino-atrial Thepericardium. Endocardium: Myocardium serous heart Epicardium of Veins, Arteries,types atria of atrioventricular and (bicuspid) the the vesselssubendocardial the atrial of and valve: which heart mitral wall semilunarventriclesventricles heart: whichblood ventricles, system node for system system portion makes has valve: It are initiation has (cardiac ventricle.valve. rightallows on lefttheventricle. transport lines three vessels: transport bundle node(SAN). a is of ofthick of contract. the are closed bundle formed th e th e up valve: between It plexus and the the left deoxygenated (AVN). muscle) lavers: th e separated allows blood blood (AVB). and walls.heart inner blood network maintenance heart heart: pulmonary trunk. between side) branches, ofand of: coordination external the toward conduction consists surface has is that Oxygenated away the left by 26 of relatively primary layer. ventricle prevent the atrioventricular the from tubes of and of right heart. cells of the mnodified forms t blood passto the that the thin constituent is the cardiac ventricle and (the formed to heart.transport contraction walls, the blood Purkinje th e atriumto pass thefromto rhythm. cardiac internal opening and valves whereas by from rightthe from atrium of the muscle the fibers). of layer the the refluxing (tricuspid the blood. the middle visceral opening of the of the left musculaturefibers There ventricular the aorta. layer. layer into on which heart. of are the the the of  of decreasing Arteries Arteries circulation Typestheof 2- 1- the arteries. wall bloodfibers. Mediumtrunk, aorta, Large body tissues. 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The smallest arteries (