The Circulatory System 3 ESSENTIAL COMPONENTS BLOOD VESSELS

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

Importance of the Circulatory System • The circulatory system has several important functions: 1. Carry nutrients and oxygen to cells 2. Carry wastes away for cells (e. g. CO 2) 3. Carry chemical messengers (hormones) throughout the body 4. Distribute heat 5. Move parts of the immune system

Components of Blood -0. 1% White Blood Cells & Platelets -99. 9% Red Blood Cells Average Person Has 5 L

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 • Haemoglobin – increases the oxygen carrying ability of the blood by 70 times (1 RBC=280 Million)

Haemoglobin • Haemoglobin is a protein made of 4 polypeptide chains • Contains “heme” groups that contain iron • O binds the heme groups

Components of the Blood White Blood Cells: • fewer 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 foreign material recognition)-

Components of the Blood Platelets: • 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