How to build a circulatory and respiratory system Every cell in an organism needs to be able to exchange gasses nutrients and waste with the environment One cell think no problem More than that need to pump fluids around Gastrovascular cavities How to build a circulatory and respiratory system Every cell in an organism needs to be able to exchange gasses nutrients and waste with the enviroment One cell thick no problem More than that need to pump fluids around Gastrovascular cavities Open and closed circulatory systems Pump Tubes Circulatory fluid How to build a circulatory and respiratory system Every cell in an organism needs to be able to exchange gasses nutrients and waste with the enviroment One cell thick no problem More than that need to pump fluids around Gastrovascular cavities Open and closed circulatory systems Pump Tubes Circulatory fluid Vertebrates have closed systems Single circulation Double circulation Pulmonary circuit or pulmocutaneous circuit Systemic circuit How to build a circulatory and respiratory system Every cell in an organism needs to be able to exchange gasses nutrients and waste with the enviroment One cell thick no problem More than that need to pump fluids around Gastrovascular cavities Open and closed circulatory systems Pump Tubes Circulatory fluid Vertebrates have closed systems Single circulation Double circulation Pulmonary circuit or pulmocutaneous circuit Systemic circuit Variations exist How to build a circulatory and respiratory system Every cell in an organism needs to be able to exchange gasses nutrients and waste with the enviroment One cell thick no problem More than that need to pump fluids around Gastrovascular cavities Open and closed circulatory systems Pump Tubes Circulatory fluid Cardiovascular Anatomy Arteries Arterioles Capillaires Venules Veins Heart atria ventricles Vertebrates have closed systems Single circulation Double circulation Pulmonary circuit or pulmocutaneous circuit Systemic circuit Variations exist 1 Blood pumped out of right ventricle and through pulmonary semilunar valve The Mammalian Heart 2 Blood travels though pulmonary arteries to lungs 3 gas exchange occurs in capillary beds of lungs 4 blood returns to heart through pulmonary veins and enters left atrium passes through left AV valve 5 and then into left ventricle Left ventricle pumps blood through aortic semilunar valve and into the aorta 6 The aorta distrubutes blood to upper 7 and lower 8 body 7 8 gas exchange occurs in the capillary beds of the body s tissues Blood returns to the heart through the superior 9 and inferior 10 vena cava and enters to right atrium 11 The Mammalian Heart Heart beat is coordinated First atria contract together Then ventricles contract together Relaxation and contraction phases have different names Diastole Systole 1 All chambers in diastole Blood flows through atria and into ventricles Note both atria and ventricles fill with blood 2 Atrial systole Ventricles still in diastole swell with extra blood that has been pumped in by atria 3 Ventricular systole atrial diastole Right and left AV valves pushed shut first heart sound Blood forced into arteries through pulmonary and aortic semilunar valves Back to 1 As ventricles enter diastole a little blood sucked back in however right and left semilunar valves snap shut second heart sound The Mammalian Heart Pacemaker cells at sinoatrial node coordinate the heart beat signal the atria to contract together first and then the ventricles to contract together second 1 As electrical signals action potentials travel from SA node and across atria the P wave is created 2 Electrical signals travel from cell to cell and are delayed briefly at AV node 3 Electrical signals travel from cell to cell to apex of heart 4 As electrical signals travel from cell to cell across ventricles the QRS complex is created NOTE P wave QRS complex and T wave are NOT action potentials More like electrical echos of the action potentials traveling across heart they are about 1000 times smaller than action potentials The Circulatory System Arteries carry blood away from heart Veins carry blood toward heart Arterioles Venules 3 layers Connective tissue tunica externa Smooth muscle tunica media Endothelium tunica interna Connected by capillary beds One cell thick plus some connective tissue mostly protein Site of gas and nutrient waste exchange Contraction of the heart muscle causes dramatic changes in the pressure inside arteries The Circulatory System The blood pressure during ventricular systole is called the systolic pressure The blood pressure during ventricular diastole is called diastolic pressure Total cross sectional area increases at the level of the capillary beds BLOOD PRESSURE DRIVES BLOOD FLOW No Pressure No Flow In general both decrease as blood moves further from the heart The Circulatory System Use a sphygmomanometer to measure blood pressure Cuff is pumped out so there is no blood flow through brachial artery Pump pressure is released as you listen for the sound of turbulent flow When blood can just squeeze through inflated cuff you can hear the turbulent flow Sounds of Korotkoff When sounds of Korotkoff are first audible cuff pressure systolic pressure Continue to release pressure on cuff When brachial artery is no longer constricted no more turbulent flow When sounds of Korotkoff can no longer be heard cuff pressure systolic pressure The Circulatory System The blood pressure during ventricular systole is called the systolic pressure The blood pressure during ventricular diastole is called diastolic pressure Total cross sectional area increases at the level of the capillary beds BLOOD PRESSURE DRIVES BLOOD FLOW No Pressure No Flow In general both decrease as blood moves further from the heart 5 quarts of blood in an average human Not enough to support all organs at their highest O2 consumption levels Blood flow regulated Vasoconstriction Vasodilation Neural circuits in the brain also regulate heart rate strength of contraction vasoconstriction and dilation throughout the entire body to regulate blood pressure The Circulatory System The blood pressure during ventricular systole is called the systolic pressure The blood pressure during ventricular diastole is called diastolic pressure Total cross sectional area increases at the level of the capillary beds BLOOD PRESSURE DRIVES BLOOD FLOW No Pressure No Flow In general both decrease as blood moves further from the heart Consider blood pressure in the