*LokDonLub

*CIRCULATORY SYSTEMS

*4 chambers : R/L atriumsR/L ventricles

H E A R T

*4 Valves : Mitral valveTricuspid valveAortic valvePulmonary semilunar valve

*Heart Wall : 1, 2EndocardiumMyocardiumEpicardium

*I. Endocardium Inner layer of atriums & ventricles2Homologous with tunica intima of blood vesselsConsist of : 1, 2Endothelium : Simple squamous epitheliumJunctions :Tight/occluding junctionsGap junctions 2. Subendocardial layer :Loose connective tissue Contain veins, nerves, Purkinje cells (branches of impulse conducting system of heartConnected to myocardium

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II. Myocardium Thickest on ventricles2Thickest tunicscardiac muscle cellsThinnest Smaller cardiac muscle cellsSpeciallized muscle cells in atrium produce atriopeptin, ANF(Atrial Natriuretic Factor), cardiodilatin, cardionatrin help in maintain fluid & electrolyte balance3

*Type Of Cardiac Muscle Fiber Conducting Impluse Fiber2. Contractile Fiber

*Conduction system of heart: 2, 3Modification of cardiac muscle cellsGenerate a rythmic stimulus Consist of : 2 node in atrium wall: Sinoatrial node/SA nodeAtrioventricular node/AV nodeAV bundle branches of AV nodePurkinje fibers branches of AV bundle1. Conducting Impulse Fiber

*Purkinje fibers : 2, 3Branches of AV BundleLocated at subendocardialDistinctive appearance with ordinary cardiac muscle :Larger & contain more cytoplasmLess myofibrilRich in mitochondria & glycogen1 or 2 central nuclei

*2. Contractile Fiber Elongated, cylindrical & branching fiberEach fiber contains only 1 or 2 nuclei, centrally placedCross striations similar to skeletal muscle (A/I/H band & M/Z line)Sarcoplasm contain numerous large mitochondria

*Special junctions at the end of two cardiac fiber3 junctions :Fascia adherens Macula adherens (desmosome)Gap junctions

*Intercalated Disc with light microscopedark lines crossed the cardiac fiber

*III. EpicardiumHomologue to tunica adventitia in blood vessels3Outermost layer of heart wall3Consist of : 1, 2Pericardium viceral mesothelium (simple squamous epithelium)Subepicardial layer loose connective tissue with coronary vessels, nerves & gangliaPericardium parietal: mesothelium & conn. tissueSpace between pericardium contain serous liquid for lubricating

*BLOOD VESSELS

*BLOOD VESSELS Differ in size, distribution & function but have similarity in several feature 2, 3Wall divided into : 1, 2, 3 Tunica Intima :Endothelium : simple squamous epthelium, rest on basal laminaProvide smooth surface of blood vesselSecreting type I, IV & V collagen, lamin, endothelin, nitric oxide, von Willebrand factor. Posses membrane bound enzyme such as angiostensin converting enzyme (ACE)Subendothelium loose conn. tissue, few scattered smooth muscle

*Tunica Media:Equivalent to myocardiumMost variable layer in size & structureContain variable amount of smooth muscle & elastic tissue depend on blood vessel functionTunica Adventitia:Correspond to epicardium lack mesothelial cellsVaries in thicknesMostly composed of fibroblast, type I collagen fiber & elastic fiber

*Blood Vessel Wall CompositionLARGE ARTERIESSMALL ARTERIESARTERIOLESCAPILLARIESVENULES &VEINSMEAN PRESSUREINSIDE DIAMETERSMALLLARGELARGE

*Membrana Elastica : Interna :Separating T. Intima & T. Media Composed of perforated elastin tissueFunction: permits diffusion of substances Eksterna :Separating T. Media & T. AdventitiaMore delicate than interna

*Vasa Vasorum : Found in large vesselsSmall arteries branching to serve nutrition to cells in t. media & t. adventitiaMore prevalent in veins than arteries coz venous blood contain less oxygen & nutients than arterial blood

*Nerve Supply Of Blood Vessel 3 A network of vasomotor nerve of sympathetic component of autonomic nervous system supplies smooth muscle cells of vessels release norepinephrine diffuse to smooth muscle cells nearby impulses propagated to entire smooth muscle via gap junctionArteries supply the skeletal muscle also receive parasympathetic nerves vasodilatation

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*ARTERIE

*A. ELASTIC ARTERIE Aorta, Iliaca Communis, Pulmonaris, Brachiocephalic, Subclavia, Carotid Comm. 2 Yellow wall coz abundance of elastin in T. mediaTunica Intima : (1, 2) Thick thicker than T. intima A. MuscularisEndothelial cells Weibel-Palade bodies von Willebrand factor (stored only in arteries)Membran elastica interna incomplete

*Thickest layer from 2 other tunica40-70 layer of elastic membran Smooth muscle (+)

*T. Adventitia :

Thin layer of fibroelastic connective tissue Vasa Vasorum (+) reach into T. Media Lymphatic vessel & nerve fibersIn elastic arteries, the tunica adventitia consists mostly of connective tissue & the vasa vasorum

*B. MEDIUM & SMALL ARTERIE Endothelial cells Weibel-Palade bodies von Willebrand factor Membran elastica interna(+)

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*Smooth muscle layer: Muscular A. : thick up to 40 layers Small A. thin

* Muscular A. as thick as T. media consist of colagen & elastin fiber Membrana elastica eksterna(+)

*Thin T. Adventitia

*Generally diameter < 0,5 mm & narrow lumenT. Intima : Sub endothelial layer very thinM. Elastica Interna (-)T. Media : Smooth Muscle 1-2 layer T. Adventitia : Very thinM. elastica eksterna (-)C. ARTERIOLE

*Metaarteriole : Branching of arteriole into capillaries 2Constriction help in regulate blood flow in capillaries 1, 2 Discontinue smooth muscle 1 Smooth muscle as pre capillary sphincter control blood flow into capillary bed 3

*Specialized Sensory Structure in Arteries3 types: carotid sinus, carotid body, aortic body monitor blood pressure & blood composition essential input to brain for controlling heart beat, respiration & BPCarotid sinus :Baroreceptor wall of carotid internal A.T. adventitia thinner & heavily endowed with sensory nerve from cranial nerve IXT. Media relatively thinner permit to be distended

*Carotid body:Chemoreceptor in bifurcation of common A.Composed of small pale staining cells in conn. Tissue 2 type : glomus (type I) cells & sheath (type II) cellsGlomus cells : large nucleus, dense cored vesicles, cell process contact with other glomus cell & capillary endothelial cellSheath cells : more long & complex process, irregular nucleiAortic body: structure similar to carotid body

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*V E I N

*Classification: 1, 2Large VeinMedium & small veins VenuleVEIN Vein wall thinner than arterie coz muscular layer & elastin layer not as well develop as arteries Vein Colaps with irregular lumen2,3 Same 3 layer as arteries

*A. LARGE VEINS Vena Cava, Renalis, Porta, Splennic etc 2 Similar to medium vein Endotelium Subendotel layer thinThin most large vein without t. mediaSmooth muscle & conn. tissue

* Thickest and well develop Smooth muscle & conn. Tissue with colagen & elastin fiberHigh power view shows the vasa vasorum, which supply blood for the wall of this large vein

*B. MEDIUM & SMALL VEINDiameter : 1 - 9 mm 1 Usually have valve 2T. Intima: endothel continue 1, 2 T. Media : Smooth muscle, colagen & elastin fiberT. adventitia : (1, 2) Thickest than t. media Smooth muscle, elastin & colagen fiber

*2 semilunar fold of T. intima project to lumen Composed of conn. tissue & lined by endotheliumNumerous in limb

*C. VENULE T. Intima : 1, 2Thin & continue endotheliumThin basal lamina with pericytesT. Media : 3Sparse conn. Tissue & few smooth muscle cellT. adventitia :(1, 2) ThinColagen & fibroblast

*Smallest blood vessel 1, 3 General structure : 2, 3T. Intima single layer of endothelium Pericytes located along outside contractile function Classification:1, 2 Continue/somatic capillaries Fenestrated/perforated capillaries SinusoidSlow blood flow (0,3 mm/detik, aorta = 320 mm/detik CAPILLARIES

*A. CONTINUE CAPILLARYFound in Conn. Tissue, muscle, CNS 1, 2Endothelium continue fasciae occludentes 3 prevent passage many moleculesForm Blood Brain Barrier permeable only to certain substances

*Similar to continue but have pores1, 3Found in : kidney, intestine, endocrine glandFenestrae : Covered with a pore diaphragm1Pore diaphragm not found in glomerulus1B. FENESTRATED CAPILLARY

*C. SINUSOID Structure : 1, 2, 3Tortouos path, greatly enlarged diameter slows the circulation of blood Endothelium cells form discontinue layerDiscontinue basal laminaMany fenestrae lack with diaphragmFound in heart & hematopoetic organs1, 2

* ARTERIOLE, VENULE & CAPILLARIE

*Return extracellular liquid to bloodstream1, 2 One direction Present in throughout body except CNS & other few areaBlind end lymphatic capillarieslymphatic vessel lymphatic ducts 1, 2, 3Lymphatic capillaries : single layer of attenuated endothelial cells with incomplete basal lamina blind end LYMPH VASCULAR SYSTEM

*Lymphatic vessel : Closely spaced valves1Large lymphatic vessel resemble small veins1 Lumina larger, walls thinnerEndothelium (+)Smooth muscle (+), collagen & elastic fiber(+)

*2 Lymphatic ducts : Consist of : 1, 2 Ductus Thoracicus Ductus Limphaticus Dexter Similar to large veins 1, 2 Vasa vasorum & rich in vascular network 1Walls : 2 T. Intima : Endothel & subendothel (+), Lamina elastica Interna (+) T. Media : smooth muscle > vein T. Adventitia : undevelop

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*REFERENCES : Histologi Dasar, Edisi 10, L. Carlos Junquira MD, Jose Carneiro MD, Robert O. Kelley PhD, EGC, 1995. pp 215-231Essentials Of Human Histology, Second Edition, William J. Krause PhD, Little Brown & Company (Inc), 1996. pp. 197-228Color Textbook of Histologi, 2nd edition, Gartner LP, Hiatt JL, WB Saunders Company, Philadelphia, Pennsylvania, 2001. Pp 251-271

*QUIZ The structure pointed by arrow is.....

*Small Arteri.Large Arteri.

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