Cardiovascular System L4 PDF | Mo Anatomy Lecture 4

Cardiovascular system lecture 4 Mo Anatomy CVS ANATOMY Arteries and veins Arteries and veins aorta Defi...

Cardiovascular system lecture 4 Mo Anatomy CVS ANATOMY Arteries and veins Arteries and veins aorta Definition The largest artery in the body Origin Arises from the left ventricle of the heart Function Carries oxygenated blood to all parts of the body 1) Ascending aorta 2) Arch of aorta Division (4 parts) 3) Descending thoracic aorta 4) Descending abdominal aorta Structure Origin Termination Branches  From the left ventricle  At the level of sternal angle (lower Right coronary artery & left coronary artery Ascending Aorta  It has 3 sinuses (dilatations) at border of 4th thoracic vertebra T4) which supply the heart the base  Continues as arch of aorta 1) Brachiocephalic artery Continuation of ascending aorta at Continues as descending thoracic aorta Arch of Aorta the level of sternal angle at the level of sternal angle (T4) 2) Left common carotid artery 3) Left subclavian artery DR. ME Page | 1 CVS ANATOMY Arteries and veins Structure Origin Termination Branches 1) Bronchial branches 2) Esophageal branches At the level of T12, enters the aortic 3) Posterior intercostal arteries Descending Continuation of arch of aorta at the opening in the diaphragm & continues as 4) Pericardial branches level of sternal angle (T4) Thoracic Aorta abdominal aorta 5) Subcostal arteries (BEPPSs) 6) Mediastinal 7) Superior phrenic arteries DR. ME Page | 2 CVS ANATOMY Arteries and veins Common Carotid Artery Subclavian Artery Brachiocephalic Artery  Left common carotid from the arch of aorta  Left subclavian arises from the aortic arch Only one brachiocephalic trunk Origin  Right common carotid from the  Right subclavian arises from the from the aortic arch brachiocephalic artery brachiocephalic artery  Main branches include: Branches/Divisions  Vertebral artery --------------  Divides into:  Internal thoracic artery  Internal carotid artery  behind sternoclavicular joint  External carotid artery Continues as the axillary artery at the lateral by dividing into Termination border of the first rib  right subclavian artery  right common carotid artery DR. ME Page | 3 CVS ANATOMY Arteries and veins Pulmonary Trunk  About 5 cm long, Origin  originates from the upper part (infundibulum) of the right ventricle at the level of the sternal end of left 3rd costal cartilage  Enters backwards and to the left, ends below the arch of aorta and in Course front of left principal bronchus by dividing into left and right pulmonary arteries at around the level of T5-T6 Superior Vena Cava  Formed by union of right & left brachiocephalic veins at the level of Origin the lower border of right 1st costal cartilage  In the right atrium at the level of right 3rd costal cartilage Termination  Drains venous blood from: Head & neck, Thoracic wall, Upper limb a) Begins opposite the lower border of 1st costal cartilage Important b) Receives the azygos vein opposite the sternal end of the 2nd costal Levels cartilage c) Ends opposite the 3rd costal cartilage to enter right atrium 1) Right & left brachiocephalic veins 2) Azygos vein opens in SVC at the level of 2nd costal cartilage Tributaries (sternal angle) 3) Mediastinal & pericardial veins DR. ME Page | 4 CVS ANATOMY Arteries and veins Brachiocephalic veins Right Brachiocephalic Vein Left Brachiocephalic Vein Formed by the union of right subclavian Formed by the union of left subclavian & & right internal jugular veins left internal jugular veins Function The right & left brachiocephalic veins unite to form the superior vena cava Inferior Vena Cava Formed by the union of the 2 common iliac veins at the level of the 5th Beginning lumbar vertebra  Pierces the central tendon of the diaphragm at the level of 8th Termination thoracic vertebra  Opens in the right atrium at the level of right 6th costal cartilage Pulmonary Veins Number Four pulmonary veins  carry oxygenated blood from the lungs to the left atrium of the heart  The two lower veins from the lower lobes of each lung Function  The upper right vein from the middle & upper lobes of the right lung  The upper left vein from the upper lobe of the left lung Posterior Mediastinum DR. ME Page | 5