Ch 22 Cardiovascular System 30 03 2010 18 21 00 Closed with two circulatory circuits Pulmonary circuit important for gas exchange o Exchanges CO2 for O2 in RBC s hemoglobin Systemic circuit important for systemic circulation o Sends nutrients removes wastes from tissues Right side of heart pulmonary circuit Left side of heart systemic circuit Blood flows through network of vessels pumped by heart that include Arteries Capillaries Veins o All exchange takes place across the capillary walls or in the smallest veins Blood Vessel walls 3 layers Innermost layer o Tunica intima endolithelium and associated connective tissue some vessles have an internal elastic membrane Middle layer o Tunica media smooth muscle layer and in some vessels plates of elastic tissue aorta pulmonary trunk Outer layer o Tunica adventitia or tunica externa connective tissue layer mainly collagen Connective tissue cell nerves and blood vessels Types of arteries Large sized or elastic arteries o Elastic layers in tunica media between the smooth muscle cells e g aorta and pulmonary trunk Also called conducting arteries Transport large voulems of blood from the heart Stretch and recoil with pressure changes Medium sized muscular arteries o Less elastic tissue in between smooth muscles e g ax Only smooth muscle Know difference Diffusion can not occur in muscular arteries must have little capillaries small arteries arterioles can change in diamete they are under sympathetic control from ANS o vasoconstriction o vasodilation characteristics of the arterial circulatory pattern o number increases moving toward capillaries o diameter increases moving toward capillaries o walls become thinner moving toward capillaries o pressure decreases thickness decreases number increases Types of capillaries Continuous o Most common type o In NS muscles and connective tissue o The only way to get in or out are the itty bitty pores Fenestrated capillaries o Two types Contains pores or fenestrations in capillary wall that permits Has a thin membrane that completes it but easy to travel Open type ONLY INT KIDNEYS Endothelium contains pores or fenestrations without any cover or caps Close type The fenstration are closed or covered over by a diaphragm like structure Sinusoid o Big openings o No basement membranes o Bone marrow Veins Fxn to collect blood from capillaries in tissue and organs and return to heart Sequence of vessels in venous system Venules Distribution of blood 30 35 in heart arteries and capillaries 65 70 in venous system o peripheral Pulmonary Circuit Arteries carry deoxygenated blood Vessels incude o Pulmonary trunk o Left and right Aortic arch Ascending aorta Brachiocephalic trunk o Right common carotid o Right subclavian Left common carotid separate off aorta Left subclavian separate off aorta Descending aorta Arm arteries Axillary artery same as subclavian but changes name Brachial artery same as axillary but changes name o Splits into radial artery and ulnar artery o Radial thumb side o Ulnar pinky side Superficial palmar arch more distal and closer to phalanges Deep palmar arch more proximal and closer to wrist Head External superifical and supply neck and head o Has branches Internal deep and supplies brain Vertebral arteries Supply brain Cerebral arteries circle o Equal blood supply to each side of the brain Circle of willis o Two vertebral come together o Form basal arteries o Basal splits and forms posterior cerebral o Two internal carotid come together Thoracic aorta Supplies thorax Abdominal Aorta Celiac trunk Superior mesenteric artery Inferior mesenteric artery 4 paired branches o suprarenal arteries adrenal glands o renal areteries kidney o gonads arteries ovaries testis o lumbarLower limb Common iliac Femoral artery Popliteal artery Posterior and anterior tibial artery Fibular small Dorsal arch Plantar arch Venous system Superior vena cava o Receives bloos from the head neck chest shoulders and upper limbs most structure above the diaphragm Inferior vena cava o Receives blood from most structure below the diaphragm Return to RA Neck veins External jugular vein internal jugular vein subclavian system right brachiocephaliac vein o where internal jugular meetssubclavian o no valves Head No valves Lower leg Can become dialated Become veracious veins o Become thick twisted and tortured looking o Great saphenous 30 03 2010 18 21 00 30 03 2010 18 21 00
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