Circulatory System Past Paper (PDF)

CIRCULATORY SYSTEM Aleksandra Wilk, PhD Department of Histology and Embryology Pomeranian Medical University in Szczecin  Plan of presentation: 1.Division of circulatory system 2.General histological structure of the wall of blood vessels 3.Types of arteries 4.Arterioles 5....

CIRCULATORY SYSTEM Aleksandra Wilk, PhD Department of Histology and Embryology Pomeranian Medical University in Szczecin  Plan of presentation: 1.Division of circulatory system 2.General histological structure of the wall of blood vessels 3.Types of arteries 4.Arterioles 5.Capillaries 6.Veins 7.Histological structure of the wall of the heart 8. A short movie – „The pump of our body – heart”  THE CIRCULATORY SYSTEM (CS) the cardiovascular system – CVS CVS ( the function is to carry blood between the heart and the tissues) the lymphatic system – LS the function is to collect lymph and deliver it back to the CVS THE CARDIOVASCULAR SYSTEM the heart : the pulmonary circuit the systemic circuit the blood vascular system: arteries capillaries veins  WHAT IS THE CIRCULATORY SYSTEM?  The circulatory system carries blood and dissolved substances to and from different places in the body.  The heart has the job of pumping these substances around the body.  The heart pumps blood and substances around the body in tubes called blood vessels.  The heart and blood vessels together make up the Circulatory System.  Our circulatory system is a double circulatory system. This means it has two parts. Lungs the right side of the the left side of the system system deals with deals with deoxygenated blood. oxygenated blood. Body cells  BLOOD VESSEL  TUNICA INTIMA  TUNICA MEDIA  TUNICA ADVENTITIA  intima TUNICA INTIMA  a single layer of endothelial cells  a subendothelial layer of loose conective tissue endothelial layer intima: single foose desmin vimentio TUNICA INTIMA Endothelium - ENDOTHELIAL CELLS  polygonal, elongated in the direction of the blood flow  bulged into the lumen  mesenchymal origin  each cell contains desmin and vimentin  filaments provide structural Photo: Property of Department of Histology and Embryology, Pomeranian Medical University support  lie on the basal lamina  miosin actin TUNICA INTIMA ENDOTHELIAL CELLS - Venules of lymph node, tonsils, Peyer’s Patch- quite high endothelial cells - Endothelial cells – numerous complexes of miosin and actin  ability of contraction and relaxation  permeability for water, molecules and some cells - Weibel- Palade bodies (endocardium, arteries, veins)  Willebrand protein (trombocytes+collagen fibers, when the vessel is demaged) - Endothelial cells have microvilli  leukocytes connect with them Weibel–Palade bodies (WPBs) are the storage granules of endothelial cells, the cells that form the inner lining of the blood vessels and heart. They store and release two principal molecules, von Willebrand factor and P-selectin, and thus play a dual role in hemostasis and inflammation.  sillariesand Post cal - venules TUNICA MEDIA capillary  concentric layers of helically arranged smooth muscle cells  some elastic fibers  reticular fibers  proteoglycans  glycoproteins Capillaries & postcapillary venules do not have a t.media.  fibrab best TUNICA ADVENTITIA clastic colleg  fibroblasts  type I collagen fibers  longitudinally oriented elastic fibers  nerves  adipose tissue Vasa vasorum –„vessels of the vessels” in large vessels  TUNICA ADVENTITIA Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  ARTERIES  A series of efferent vessels  Function: transport the blood with oxygen and nutrients to the tissues and organs. Elastic  Classification of arteries:  Elastic  Muscular  Arterioles  ELASTIC ARTERIES intima;endo /sub fibroblast muschante · internal thie In Muscle cells Galle, · Media: reticle,  the largest arteries  helpful in keeping stable blood flow  Intima: lined with endothelium, subendothelial layer, collagen and elastic fibers, fibroblasts, internal elastic lamina; is thicker than corresponding tunica of muscular artery  Media: concentric arranged, perforated elastic laminae (30-75), vascular smooth muscle cells, reticular and collagen fibers, proteoglycans, glycoproteins, external elastic lamina  Adventitia: connective tissue, well developed, nerves, vasa vasorum Adventilia;cot, van  ELASTIC ARTERIES 1. Tunica intima Lined with endothelium, (nexus) 2. Tunica media With elastic laminae, vascular smooth muscle cells (nexus) 3. Tunica adventitia Photo: Property of Department of Histology and connective tissue, vasa Embryology, Pomeranian Medical University vasorum ELASTIC ARTERIES TUNICA MEDIA nuclei of vascular smooth muscle cells Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  ELASTIC ARTERIES ELASTIC resorcin ARTERY fuchs orewin Photo: Property of Department of Histology and Embryology, Pomeranian Medical University Staining for elastic arteries: resorcine-fuchsin and orcein ELASTIC ARTERIES Photo: Property of Department of Histology and Embryology, Pomeranian Medical University ELASTIC ARTERIES Photo: Property of Department of Histology and Embryology, Pomeranian Medical University ELASTIC ARTERIES Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  MUSCULAR ARTERY  the medium-sized arteries  control the affluence of blood to the organs by contracting or relaxing the SMC of the media  Intima: lined with endothelium, subendothelial layer, the internal elastic lamina is prominent, thicker in older people (migration of SMC from t. media)  Media: up to 40 layers of smooth muscle cells (zonula adherens, occludens), elastic fibers, reticular fibers, proteoglycans, glycoproteins, external elastic lamina  Adventitia: connective tissue, vasa vasorum, nerves Media:Ho larger interval i the agel -  MUSCULAR ARTERY t. adventitia t. intima t. media MUSCULAR ARTERY Photo: Property of Department of Histology and Embryology, Pomeranian Medical University ELASTIC VS MUSCULAR ARTERY  MUSCULAR ARTERY Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  MUSCULAR ARTERY Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  MUSCULAR ARTERY Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  ARTERIOLES  narrow lumen (less than 0.5 mm in diameter)  Intima: lined with endothelium, subendothelial layer is very thin, no internal elastic lamina in very small arterioles;  Media: 1 or 2 circulary arranged layers of smooth muscle cells, no external elastic lamina;  Adventitia: very thin endonin e Fin ARTERIOLES Photo: Property of Department of Histology and Embryology, Pomeranian Medical University  CAPILLARIES  Single layer of endothelial cells, rolled into a tube, resting on a basal lamina.  They permit metabolic exchange between blood and surrounding tissues.  CAPILLARIES continuous Three types of capillary fenestrated continuous – most common dis fenestrated – have pores discontinuous sinusoidal  PERICITES support cellsfor Capillares and Small venules  have their own basal lamina  mesenchymal origin  located along the outside of the capillaries and small venules  possess a small Golgi complex, mitochondria, rER, microtubules  contain myosin, actin, tropomyosin and protein kinase, which are all related to contraction FUNCTIONS OF PERICYTES I CAPILLARIES  CONTINUOUS CAPILLARIES exocrine - Ca musche  no fenestrae  blood-brain barrier  basal lamina is present  muscle tissue and well developed  connective tissue  can fuse  exocrine glands CONTINUOUS CAPILLARIES  FENESTRATED CAPILLARIES endoci it  several circular  endocrine glands transcellular openings in  intestine endothelial cells  renal glomerulus  Continous basal lamina important  SINUSOIDAL CAPILLARIES liver  no basal lamina or  liver spleen discontinuous  spleen  each endothelial cell is  bone marrow separated from another by wide space  enlarged in diameter  function: facilitate exchange between blood and tissues  CAPILLARY BED  An interconnected network of vessels running through tissues  Consists of: - Metarterioles - Capillaries - Venules  CAPILLARY BED Precapillary sphincters - regulate the flow of blood to tissues Most tissues have a rich supply, but there are a few exceptions › Tendons and ligaments / poorly vascularized › Cartilage / from adjacent connective tissue › Epithelia / from adjacent connective tissue › Cornea / nourished by aqueous humor veins VEINS Advant  Blood vessels formed by a convergence of the capillaries into a system of channels.  They become larger in diameter as they approach the heart.  Blood vessels that carry blood toward the heart.  Higher in diameter than arteries.  Rather elongated or oval than round in shape.  Adventitia is the best developed layer.  POSTCAPILLARY VENULES ↳ don't - have 0.1 to 0.5 mm in diameter tunica inBma – endothelium and thin subendothelial layer pericytes  SMALL OR MEDIUM-SIZED VEINS S/M.U no = suendo  muscular  thin wall  1-9 mm in diameter V =Well developed  collapsed adventitie  intima: lined with endothelium, thin or no subendothelial layer  media: small bundles of smooth muscle cells intermixed with reticular fibers  adventitia: well developed, collagen fibers, fibroblasts, nerves, vasa vasorum ARTERY VS VEIN  LARGE VEINS Advntilia:thits ↳ media thir  big venous trunks, close to the heart  intima: well developed  media: thin, few layers of smooth muscle cells, aboundance of collagenous tissue  adventitia: the thickest, the best developed layer, longitudinal layers of smooth muscle cells  valves in their interior Valves: 2 semilunar folds of the tunica intima that projects into the lumen.  BLOOD VESSELS The contraction of muscles compressing veins helps push blood up through the leg veins back to the heart. The valves allow the blood to flow towards the heart only. Valves Valves OPEN CLOSED  HEART  muscular organ, contracts rythmically  produces atrial natriurethic factor  STRUCTURE OF THE WALL:  endocardium  myocardium  epicardium  pericardium HEART HEART  HEART CARDIAC FIBROUS SKELETON  Central region of the heart.  A site of origin and insertion of the cardiac muscle cells.  Dense connective tissue:  septum membranaceum  trigona fibrosa  annuli fibrosi  HEART ENDOCARDIUM  homologous with the t. intima of blood vessles  single layer of squamous endothelial cells  a thin subendothelial layer of loose connective tissue  Muscular-elastic layer  the subendocardial layer (with veins, nerves and Purkinje cells)  HEART MYOCARDIUM  the thickest layer  homologous with the t. media of blood vessles  consists of cardiac muscle arranged in layers and grouped into three populations: contractile cells the impulse-generating and conducting cells specialized cardiac muscle cells located in the atrial wall -atrial natriuretic polypeptide.  HEART EPICARDIUM  serous covering of the heart and forming the visceral layer of the pericardium  homologous with the t. adventitia of blood vessels  covered externally by mesothelium WALL OF THE HEART Endothelium, subendothelial tissue, muscular- elastic layer, subendocardium Photo: Property of Department of Histology and Embryology, Pomeranian Medical University WALL OF THE HEART Photo: Property of Department of Histology and Embryology, Pomeranian Medical University ENDOCARDIUM Photo: Property of Department of Histology and Embryology, Pomeranian Medical University PERICARDIUM Protective sac of connective tissue Surrounds the heart Filled with fluid WALL OF THE HEART  STRUCTURES THAT CONTROL HEARTBEAT  the sinoatrial node  internodal tracts  the atrioventricular node  the bundle of His  Purkinje cells  LYMPHATIC VASCULAR SYSTEM  Returns the extracellular liquid (lymph) to the bloodstream.  The lymph circulates in 1 direction only.  Lymphatic vessels:  found in all organs  blind-ended  consist of a single layer of endothelium  numerous internal valves  no fenestrations in their endothelial cells  absorb some of electrolytes and proteins that leave the blood capillaries.  HEART h=ps://www.youtube.com/watch?v=GMBSU-2GK3E h=ps://www.youtube.com/watch?v=ebzbKa32kuk h=ps://www.youtube.com/watch?v=-s5iCoCaofc THANK YOU