Cardiovascular System Exam Study Guide Review 2023/2024

Cardiovascular System Exam Study Guide Review 2023/2024. Interesting Facts • Your entire volume of blood goes through your entire body once every minute • Humans have ~60,000 miles of blood vessels in their bodies (more than twice the circumference of the earth!) • Your heart beats 100,000 times and pumps ~2000 gallons of blood every day • Pig and baboon hearts have been transplanted into humans Cardiovascular System • Heart, vessels, blood • Function: transport gases, nutrients, wastes, hormones The Heart • Size of a fist; less than a pound • In thorax; flanked by lungs; rests on diaphram • Top: base • Bottom: apex Pericardium • Double-layered sac covering the heart • Outer layer anchors heart in chest • Inner layer (epicardium) attached to heart wall • Lubricating fluid in pericardial space (between layers) reduces friction Heart Wall 3 layers: • Epicardium: outer wall joined with pericardium • Myocardium: the actual cardiac muscle that contracts • Endocardium: lines heart chambers & vessels Heart Chambers Four chambers: • 2 atria: top of heart – receive blood from veins • 2 ventricles: bottom of heart – pump blood through arteries Heart Chambers • Septum: divides left from right heart • Valves: keep blood flowing in one direction • Four valves: • 2 AV valves, • 2 semilunar valves Heart sounds (Lupp-dupp) from valves closing Atrioventricular Valves AV valves: between atria and ventricles • Bicuspid (mitral) valve: on the left • Tricuspid valve: on the right • When valves are open blood drains from atria into ventricle • When ventricle contract, valve flaps are forced shut, blocking blood from reentering atria Semilunar Valves • Located in arteries leaving ventricles • Pulmonic valve: at base of pulmonary artery • Aortic valve: at base of aorta • When ventricles contract, valves are forced open & let blood flow • When ventricle relaxes, backflow of blood fills flaps of valve & forces them to shut Blood Vessels • Arteries: carry Blood Vessels blood away from the heart • Veins: carry blood to the heart • Capillaries: connect arteries to veins & exchange gases with tissues Arteries • Carry blood at high pressure • Very thick, stretchy walls that expand in size • Most carry oxygenated blood