Study Guide for AP2 Cumulative portion Cardiovascular system and blood vessels I II III IV V VI Pulmonary circuit right side of the heart supplies blood to the lungs for gas exchange a Pulmonary artery carries deoxygenated blood and the pul Vein is the only vein to have oxygenated blood Systemic circuit left side of the heart supplies the tissues of the body Pericardium bundle of fibrous tissue that encloses and protects the heart a Forms a wall around the heart Myocardium thick muscular layer with a fibrous skeleton a Structural support electric nanoconductor FLOW OF BLOOD THROUGH THE HEART a Left ventricle Aorta aortic arch thoracic trunk body right atrium Right AV valve right ventricle pulmonary artery lungs pulmonary vein left atrium left AV valve Function of chambers of the heart a Left atrium receives blood from the lungs pumps blood into left ventricle on i Contains the electronic pacemaker of the heart b Left ventricle pumps oxygenated blood to the body and tissues upon contraction i Largest most muscular chamber of the heart c Right atrium receives deoxygenated blood from the body and pumps it into the right contraction ventricle d Right Ventricle pumps blood out towards the lungs i The ventricles of the heart are larger and more muscular than the atria of the heart due to the fact that they have to pump the blood throughout the systemic and pulmonary circuits e Valves valves are needed to ensure that the blood does not flow backwards or mix with the other chambers of the heart This makes the heart inefficient and can harm the body Valves are opened by the force of the blood pushing on them in only one direction VII Definitions a Papillary muscles involved with the opening and closing of the AV valves during contraction of the heart b Chordae tendinae the cartilaginous fibers that connect the papillary muscles to the AV c valves Interventricular septum thick muscular wall that separates the ventricles from each other Anatomy of the blood vessels I II III The function of the Tunica Interna is to line the inside of the blood vessels with a layer of endothelium the function of the tunica media is vasomotion of the blood vessels Elastin portion accounts for flexibility Blood vessels a arteries transport blood away from the heart Experience high pressure and have the thickest tunica media b veins farthest vessels from the heart these vessels experience the lowest pressure and c contain valves to maintain the venous return to the heart capillaries smallest blood vessels used to connect arteries to veins and for nutrient and gas exchange with the tissues conducting arteries aorta and branches closest arteries to the heart which experience the greatest amount of pressure Contain much elastin in order to account for pressure changes arterioles the smallest arteries of the body the largest have all 3 layers and tunica media is mainly smooth muscle a metarterioles link arterioles and venules Have individual smooth muscle cells b Precapillary sphincter valve that encircles the entrance to a capillary bed and determines which areas receive the most blood IV V VI VII Baroreceptors located in the elastic arteries and aortic arch These vessels control blood pressure Chemoreceptors found close to the carotid and aortic baroreceptors these receptors detect changes in the chemical composition of the blood pH O2 saturation etc VIII Capillaries to pass through a Continuous continuous uninterrupted lining allow passage of water and small ions only b Fenestrated pores in the endothelial cells allow for small molecules and some proteins c Sinusoid large openings in the endothelium allow for the transfer of red and white blood cells discontinuous basal lamina IX X XI XII Common circulatory route heart arteries arterioles capillaries venules veins Portal system blood flows through several consecutive capillary networks before returning to heat Anastomosis point where 2 blood vessels merge provide alternate route for blood supply Capillary exchange a Nutrients gases and wastes are exchanges by diffusion through the capillary pores b Hydrostatic pressure pushes out on the capillary walls greater than the osmotic pressure at the arterial end c Osmotic pressure pushes in to the capillary as there is a greater concentration of water molecules on the outside of the blood vessel than on the inside due to salts and other elements in the blood equals the hydrostatic pressure in the middle of the capillary i Hydrostatic pressure osmotic filtration ii Osmotic pressure hydrostatic reabsorption XIII Mechanisms for venous return a Gravity blood that is above the heart in the brain arms etc is aided by the force of b Muscle contraction contractions of skeletal smooth muscle pushes on the walls of the gravity to return to the heart veins and back to the heart c Respiratory activity venous return increases when the right atrial pressure decreases XIV Definitions a Bulk flow movement of material in and out of a cell Exocytosis pinocytosis endocytosis b Solvent drag when solutes in a solution are transported by moving water instead of ion pumps or membrane transport Ischemia restriction in blood supply to the tissues c d Hydrostatic pressure pressure exerted by a fluid due to the force of gravity e Colloid systemic pressure pressure exerted by proteins in the bloodstream that tends to pull water into the capillaries f Angina pain due to lack of blood flow to the heart g Myocardial infarction interruption of circulation to the heart causing death of heart i Pulmonary buildup of fluids in the lungs due to failure of the right ventricle ii Systemic buildup of tissues in the body tissues due to failure of the left muscle tissue h Edema ventricle Heart physiology I II III Heartbeat involves contraction and relaxation of all 4 chambers of the heart atria contract first and push blood into ventricles which in turn contract and push the blood into the respective circuits a 4 phases ventricular filling isovolumetric contraction ventricular ejection isovolumetric relaxation b Systole contraction of the ventricles c Diastole relaxation of the ventricles Cardiac muscle fiber cardiac muscle is striated like skeletal muscle but cardiocytes are short and branched in comparison T tubules are larger and intercalated discs connect each cardiocyte end to end Functions and components of the cardiac conduction system a SA node pacemaker of the heart depolarizes and stimulates the AV node to fire which triggers a contraction