(erythocytes = red; platelets = yellow; T-lymphocyte = light green)

COMPONENTS OF BLOOD (video) A. Plasma: 55 % of blood B.     Formed Elements: 45% -- Erythrocytes (RED BLOOD CELLS) -- Leukocytes (WHITE BLOOD CELLS) -- Thrombocytes (PLATELETS)

FEATURE RED BLOOD CELLS WHITE BLOOD CELLS PLATELETS SHAPE Biconcave disc Variable, Amoeboid Tiny, Cell fragments FUNCTION Transport O2 and CO2 Combat infection Blood clotting ORIGIN Bone marrow Lymphoid Tissue Bone Marrow ALSO CALLED Erythrocytes Leukocytes Thrombocytes

Blood – Plasma – contains…. Water - and dissolved in it… a lot of stuff Blood proteins -Albumin - osmotic balance (liver) -Fibrinogen - blood clotting (liver) Gases (O2, CO2) Nutrients (fats, glucose, amino acids, nucleotides) Wastes (urea, ammonia) Vitamins Hormones Salts

Blood - Cells 1. RBC- most numerous a biconcave disc - why??? Lack a nucleus live for 120 days – why?? In the cell is Hemoglobin – which binds to oxygen – called oxyhemoglobin

Blood Cells largest in size contain nucleii 2. White Blood Cells largest in size contain nucleii Function: to fight infection Some are phagocytic

Blood Cells 3. Platelets Very small & irregular in shape cell fragments Function – blood clotting

All blood cells made in the bone marrow of the large bones.

Clotting

Need three things in blood Blood Clotting-  Need three things in blood 1)    Platelets 2)    Prothrombin 3)    Fibrinogen   - Platelets clump at the site of the “leak” and partially close it then initiate a sequence of events to activate fibrinogen.

Clotting – produces an insoluble fiber – fibrin, requires calcium ions Damaged vessel and platelets release prothrombin activator (an enzyme called thromboplastin) (with Ca2+) prothrombin activator enzymes catalyze the conversion of Prothrombin  Thrombin Thrombin activates Fibrinogen  Fibrin Fibrin has sticky ends and forms a lattice or network over the leak. Blood cells get trapped and form a clot.

RBC trapped in the FIBRIN network

Human Blood Types Antigen – an agent that is foreign (or self) and is recognized by the immune system Antibody – a Y shaped protein capable of identifying and binding to a specific antigen

Agglutination – Antibodies connect to the antigen of the pathogen and round up the infection in one area (a clump)