Circulatory System circulatory system circulatory system transports O 2 and nutrients to cells transports O 2 and nutrients to cells takes away CO 2 and other wastes takes away CO 2 and other wastes

Circulatory System: Gastrovascular Cavity Gastrovascular cavity – no need for circulatory system cnidarian & flatworms Gastrovascular cavity – no need for circulatory system cnidarian & flatworms

Circulatory System: Open vs Closed Open systems Open systems Heart pumps blood through open-ended vessels into spaces between cells Heart pumps blood through open-ended vessels into spaces between cells

Circulatory System: Closed Closed systems Closed systems Heart pumps blood through arteries and capillary beds Heart pumps blood through arteries and capillary beds Blood returns to heart via veins Blood returns to heart via veins

Circulatory System: Heart Chambers Fish = 2 chambers (atrium, ventricle) Fish = 2 chambers (atrium, ventricle) Amphibians / Reptiles = most have 3 chambers (2 atria, 1 ventricle); crocodiles are exception, have 4 chambers Amphibians / Reptiles = most have 3 chambers (2 atria, 1 ventricle); crocodiles are exception, have 4 chambers Birds / Mammals = 4 chambers (2 atria, 2 ventricle) Birds / Mammals = 4 chambers (2 atria, 2 ventricle)

Circulatory System: Heart Chambers in Different Animals

Circulatory System: Blood Vessels Artery = AWAY from heart / thick muscle and tissue Artery = AWAY from heart / thick muscle and tissue Veins = Towards heart / valves Veins = Towards heart / valves Capillaries = where diffusion occurs / thin epithelial lining Capillaries = where diffusion occurs / thin epithelial lining

Circulatory System: Blood Vessels Capillaries Capillaries Veins Veins

Circulatory System: Circuits Pulmonary circuit Pulmonary circuit Heart lungs (or equivalent) Heart lungs (or equivalent) Systemic circuit Systemic circuit Heart body Heart body

Circulatory System: Mammal Heart Atria (top) Atria (top) Ventricles (bottom) Ventricles (bottom) Valves (AV/ SL) Valves (AV/ SL) Aorta / Inferior and Superior Vena Cava Aorta / Inferior and Superior Vena Cava Pulmonary Artery/Vein Pulmonary Artery/Vein

Circulatory System: Path of Blood

Circulatory System: Cardiac Cycle Diastole: relaxed and blood flows in Diastole: relaxed and blood flows in Systole - contract Systole - contract Atria Atria ventricles ventricles

Circulatory System: Pacemaker SA node (pacemaker) sends electrical signals  contraction of the atria SA node (pacemaker) sends electrical signals  contraction of the atria AV node  ventricles AV node  ventricles

Circulatory System: Blood Pressure Pressure: highest in arteries (therefore, thickest blood vessel) Pressure: highest in arteries (therefore, thickest blood vessel) Drops to zero when blood reaches veins Drops to zero when blood reaches veins 120/80 120/80

Figure Withdraw blood Place in tube PLASMA 55% CONSTITUENTMAJOR FUNCTIONS Water Solvent for carrying other substances Salts Osmotic balance, pH buffering, and regulation of membrane permeability Sodium Potassium Calcium Magnesium Chloride Bicarbonate Plasma proteins Osmotic balance, pH buffering Clotting Immunity Albumin Fibrinogen Immunoglobins (antibodies) Substances transported by blood Nutrients (e.g., glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones Centrifuge CELLULAR ELEMENTS 45% CELL TYPENUMBER (per mm 3 of blood) FUNCTIONS Erythrocytes (red blood cells) 5–6 millionTransport of oxygen (and carbon dioxide) Leukocytes (white blood cells) 5,000–10,000 Defense and immunity Basophil Eosinophil Neutrophil Lymphocyte Monocyte Platelets 250,000– 400,000 Blood clotting

Circulatory System: Erythrocytes (RBC) Red blood cells contain hemoglobin Red blood cells contain hemoglobin Hemoglobin enables transport of O 2 Hemoglobin enables transport of O 2 No nucleus so maximize room for hemoglobin No nucleus so maximize room for hemoglobin Few months life span Few months life span

Circulatory System: Leukocytes (WBC) White blood cells function both inside and outside circulatory system White blood cells function both inside and outside circulatory system Fight infections and cancer Fight infections and cancer

Circulatory System: Platelets & Clotting platelets – clotting when vessels damaged platelets – clotting when vessels damaged Help make fibrin (web) for clot

Circulatory System: Blood Type

Blood TypeReceive FromGive to A A, O A, AB B B, O B, AB AB A, B, AB, O AB O O A, B, AB, O