The Circulatory System 3 ESSENTIAL COMPONENTS BLOOD Carrier VESSELS TRANSPORTS THE BLOOD HEART PUMPS THE BLOOD THROUGH THE BODY

Importance of the Circulatory System

Components of Blood Average Person Has 5L -0.1% White Blood Cells & Platelets -99.9% Red Blood Cells Average Person Has 5L

Components of the Blood Red Blood Cells (RBC’s) Also known as Erythrocytes White Blood Cells (WBC’s) Also known as leukocytes Platelets

Components of the Blood Red blood cells: Biconcave Structure allows them to fit through small vessels called capillaries Do not contain a nucleus Packed with hemoglobin which attracts & binds oxygen Hemoglobin increases the oxygen carrying ability of the blood by 70 times (1 RBC=280 Million)

Hemoglobin

Components of the Blood White Blood Cells: Less WBC’s than RBC’s (1:700) Have a nucleus Immune system relies on WBC’s to attack viruses, bacteria or other foreign substances that may enter the body Form antibodies (used for foreign material recognition)-does not attack objects themselves-they alert WBC’s to attack

Components of the Blood Platelets: Similar to RBC’s, these cells contain a nucleus Move through blood until they strike any sharp object or torn tissue, then they rupture Release chemicals that create a mesh of fibres

Platelet Importance Red blood cells get caught in fiber mesh Creation of Blood Clots

Bone Marrow RBCs, WBCs and platelets are all produced in the bone marrow

Work Session Read Pages 316-322 in Wesley Biology Text Work on filling in the Circulatory Work Sheet (Description & Functions) First 7 relate to todays lecture If finished, read ahead to complete as much as you can to prep for next lessons! Intro to Pulse & Blood Pressure Lab! (if we have time)