Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Blood  Type of connective tissue  The only fluid tissue in the human body  38 degrees celsius or degrees farenheit  Slightly alkaline, pH  About 5x’s thicker than water 5.3 Q average adult  More blood in males than females Account for approximately 8% of body weight

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Functions: Transport, Regulation and Protection The transport functions include:  carrying oxygen and nutrients to the cells.  transporting carbon dioxide to the lungs (for removal)  transporting nitrogenous wastes to the kidneys (for removal)  carrying hormones from the endocrine glands to the target tissues. The regulation functions include:  removing heat from active areas, such as skeletal muscles, and transporting it to other regions or to the skin where it can be dissipated (maintaining body temp)  pH regulation through the action of buffers in the blood. The protection functions include:  preventing fluid loss by forming clots  protect the body against microorganisms that cause disease

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 2 Parts of Whole Blood 1.Cells (formed elements)  living component  45% of total blood  3 main types  formed in red bone marrow of long bones, some in other organs as needed 2.Plasma (matrix)  non-living component  55% of total blood  mainly water (90%)  over 100 dissolved substances ex. nutrients, salts (electrolytes), gases, hormones, proteins, carbs, amino acids, vitamins, carbon dioxide, urea, ammonia

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 2. Plasma (matrix)  non-living component  55% of total blood  mainly water (90%)  over 100 dissolved substances ex. nutrients, salts (electrolytes), gases, hormones, proteins, carbs, amino acids, vitamins, carbon dioxide, urea, ammonia  Plasma proteins  Most abundant solutes in plasma  Most are made by the liver Ex. Albumin—regulates osmotic pressure and thickens blood Clotting proteins—help when a blood vessel is injured

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Separating Blood Components Layers are based on density  Plasma rises to the top  Thin white middle layer: Buffy coat: contains white blood cells (leukocytes) and platelets)  Red Blood Cells: Erythrocytes: sink to the bottom (% is known as the hematocrit) Red Blood Cells

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 2 Main Formed Elements (Blood Cells)  Erythrocytes  Red blood cells (RBCs)  Leukocytes  White blood cells (WBCs)  Platelets  Cell fragments and not whole cells, necessary for blood clotting

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings All formed elements stem from a specific type of cell  Lost cells are replaced by division of hemocytoblasts (blood stem cells) in the red bone marrow

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 1. Erythrocytes  Commonly known as red blood cells or RBCs  Main function is to carry oxygen  Anatomy of circulating erythrocytes  Biconcave disks  Essentially bags of hemoglobin  Anucleate (no nucleus)  Contain very few organelles *4-6 million RBCs per cubic millimeter of blood

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Formation of Erythrocytes  Unable to divide, grow, or synthesize proteins  Wear out in 100 to 120 days  RBCs are eliminated by phagocytes in the spleen or liver

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hemoglobin  Iron-containing protein  Binds strongly, but reversibly, to oxygen  Each hemoglobin molecule has four oxygen binding sites  Each erythrocyte has 250 million hemoglobin molecules  Hemoglobin is recycled in the body *Normal blood contains 12–18 g of hemoglobin per 100 mL blood

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 2. Leukocytes  commonly known as white blood cells or WBCs  Crucial in the body’s defense against disease  These are complete cells, with a nucleus and organelles  Able to move into and out of blood vessels  Respond to chemicals released by damaged tissues  Many types of WBC’s some are macrophages and some produce antibodies or histamine *4,000 to 11,000 WBC per cubic millimeter of blood

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Formed Elements  Types of leukocytes  Granulocytes  Granules in their cytoplasm can be stained  Possess lobed nuclei  Include neutrophils, eosinophils, and basophils  Agranulocytes  Lack visible cytoplasmic granules  Nuclei are spherical, oval, or kidney- shaped  Include lymphocytes and monocytes

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Formed Elements  List of the WBCs from most to least abundant  Neutrophils  Lymphocytes  Monocytes  Eosinophils  Basophils Types will vary depending on a persons health at the time  Easy way to remember this list  Never  Let  Monkeys  Eat  Bananas

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings  Neutrophils  Multilobed nucleus with fine granules  Act as phagocytes at active sites of infection  Eosinophils  Large brick-red cytoplasmic granules  Found in response to allergies and/or parasitic worms Types of granulocytes

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings  Basophils  Have histamine-containing granules  Initiate inflammation

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of agranulocytes  Lymphocytes  Nucleus fills most of the cell  B-lymphocytes produce antibodies —collect and clump bacteria together, easier for phagocytes to “eat” them  T-lymphocytes directly attack cells that do not belong (cell tag receptor incorrect)  Monocytes  Largest of the white blood cells  Function as macrophages  Important in fighting chronic infection

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 3. Platelets  Derived from ruptured multinucleate cells (megakaryocytes)  Needed for the clotting process  Normal platelet count = 300,000/mm 3