Lecture 9: CVS PDF

 Cardiovascular system Heart  Cover: heart is covered by pericardium which is formed of:  Fibrous pericardium wy  Serous pericardium formed of: visceral layer & parieta...

 Cardiovascular system Heart  Cover: heart is covered by pericardium which is formed of:  Fibrous pericardium wy  Serous pericardium formed of: visceral layer & parietal layes and pericardial cavity inbetween  Site: behind sternum “only 1/3 of heart is on the right side” da  Wall: formed of endocardium , myocardium & pericardium en  Chambers:2 atria "receive blood " & 2 ventricles “pump blood”  Parts: H  Apex:formed by left ventricle.  Base: formed by 2 atria mainly left atrium R.  Sterno-costal surface: formed by 4 chambers  Diaphragmatic surface: formed by both ventricles D Anatomist “CVS ”  wy  Arterial supply: coronary arteries Origin: from ascending aorta da  Venous drainage: coronary sinus Termination: into posterior wall of right atrium en  Nerve supply: autonomic nerve supply Sympathetic: increase the heart rate H Parasympathetic: decreases the heart rate R. D Anatomist “CVS ”  Circulations: 1. Pulmonary circulation: blood flow between heart & lungs. “Right ventricle pump deoxygenated blood through pulmonary trunk to lung which returns oxygenated blood to left atrium wy through pulmonary veins” 2. Systemic circulation: blood flow between heart & body “Left ventricle pump oxygenated blood through aorta to the da body which return deoxygenated blood to right atrium through superior & inferior vena cava” Valves of heart en  AV “atrio-ventricular” valves:  Mitral valve between left atrium & left ventricle H  Tricuspid valve between right atrium & right ventricle  Semilunar valves: Pulmonary & Aortic valve: prevent blood to go back into ventricles R. 3. Portal circulation: the flow of blood between digestive tract & liver Blood passes between 2 sets of capillaries as it passes from GIT to liver through portal vein then from liver to IVC through hepatic veins. D Anatomist “CVS ”  Vessels Difference between arteries & veins: Artery Vein  Carry blood away from the heart  Carry blood towards the heart  Carry oxygenated blood except pulmonary artery  Carry deoxygenated blood except pulmonary veins wy  Thick wall & narrow lumen  Thin wall & wide lumen  Has pulse  No pulse da  Higher blood pressure  Lower blood pressure  Wall is rich in elastic tissue & smooth muscles  Wall is poor in elastic tissue & smooth muscl  Have branches  Have tributaries en  No valves  Have valves H R. D Anatomist “CVS ” Arterial anastemosis o Definition: communication between terminal parts of adjacent arteries o Function: collateral circulation if an artery becomes occluded wy o Example: around joints of limbs & at the hand, foot End arteries: da o Definition: arteries with no anastomosis with adjacent arteries. o Disadvantage: Their occlusion causes death of the tissue supplied. en o Example: retinal, renal, splenic, cerebral, coronary & pulmonary arteries Wavy “tortious”artery H o Definition: Arteries with wavy course supplying expansible or moving organs o Example: Facial, lingual, splenic & uterine arteries R. D Anatomist “CVS ” Communtication between arteries & veins 1. Capillaries:  Defintion: Simple endothelial network between arteriole & venule  Site: all over the body except Cornea & cartilage & skin epidermis wy 2. Arterio-venous shunt:  Definition: direct communication between arterioles & venules da  Site & Function: o In skin dermis: to control temperature en o In intestine: for food absorption o In erectile organs: help in erection 3. Blood sinusoids: H R.  Chracter: Wide spaces incompletely lined by phagocytic cells “Kupffer cells”  Site: liver, spleen, bone marrow D Anatomist “CVS ”