Blood: An Overview Ch. 10a

Blood Slide 10.1a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The only fluid tissue in the human body  Classified as a connective tissue w/ 2 parts:  Formed Elements = Living Cells within the blood (45% of blood volume)  Plasma = Non-Living matrix, “liquid” part of blood (55% of blood volume)

Blood Slide 10.1b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 10.1

What are the physical characteristics of blood?

Physical Characteristics of Blood Slide 10.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Blood Color range  Oxygen-rich blood is scarlet red  Oxygen-poor blood is dull red  Blood is NEVER blue!  pH must remain between 7.35–7.45  Blood temperature is slightly higher than body temperature

Which drop o blood is oxygen rich? 2 1

Quick Quiz What color is oxygen poor blood?

Blood: Plasma Components

Blood Plasma: The liquid part Slide 10.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Composed of approximately 90 percent water  Includes many dissolved substances  Nutrients  Salts (metal ions)  Respiratory gases  Hormones  Proteins  Waste products

Plasma Proteins Slide 10.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Albumin – regulates osmotic pressure  Clotting proteins – help to stem blood loss when a blood vessel is injured  Antibodies – help protect the body from antigens

Quick Quiz What do you think the main function of blood plasma is? Name one of the plasma proteins and its function.

Blood: Formed Elements

Formed Elements Slide 10.5a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Erythrocytes = red blood cells  Leukocytes = white blood cells  Platelets = cell fragments

Slide 10.5b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Slide 10.5c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Erythrocytes

Erythrocytes (Red Blood Cells) Slide 10.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The main function is to carry oxygen  Anatomy of circulating erythrocytes  Biconcave disks  Essentially bags of hemoglobin  Anucleate (no nucleus)  Contain very few organelles  Outnumber white blood cells 1000:1

Hemoglobin Slide 10.7  Found within Red Blood Cells  Gives bright red color when oxygen is present  Iron-containing protein  Binds strongly, but reversibly, to oxygen  Each hemoglobin molecule has four oxygen binding sites  Each erythrocyte has 250 million hemoglobin molecules

Quick Quiz What is the function of red blood cells? What is so important about hemoglobin?

Leukocytes

Leukocytes (White Blood Cells) Slide 10.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  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 (diapedesis)  Can move by ameboid motion  Can respond to chemicals released by damaged tissues

Leukocyte Levels in the Blood Slide 10.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Normal levels are between 4,000 and 11,000 cells per millimeter  Abnormal leukocyte levels  Leukocytosis  Abnormally high luekocyte level  Generally indicates an infection  Leukopenia  Abnormally low leukocyte level  Commonly caused by certain drugs

Types of Leukocytes Slide 10.10a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Granulocytes  Granules in their cytoplasm can be stained  Include neutrophils, eosinophils, and basophils Figure 10.4

Granulocytes Slide 10.11a Copyright © 2003 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 repsonse to allergies and parasitic worms

Granulocytes Slide 10.11b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Basophils  Have histamine-containing granules  Initiate inflammation

Types of Leukocytes Slide 10.10b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Agranulocytes  Lack visible cytoplasmic granules  Include lymphocytes and monocytes Figure 10.4

Agranulocytes Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymphocytes  Nucleus fills most of the cell  Play an important role in the immune response  Monocytes  Largest of the white blood cells  Function as macrophages  Important in fighting chronic infection

Quick Quiz What is the main function of Leukocytes?

Platelets

Platelets Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Derived from ruptured multinucleate cells (megakaryocytes)  Parts of broken down cells  Needed for the clotting process  Normal platelet count = 300,000/mm 3

Quick Quiz What is the function of platelets? What are platelets made of?

How is blood formed?

Blood Cell Formation Slide  Hematopoiesis  Blood cell formation  Occurs in red bone marrow  All blood cells are derived from a common stem cell (hemocytoblast)  Hemocytoblast differentiation  Lymphoid stem cell produces lymphocytes  Myeloid stem cell produces other formed elements

Erythrocytes

Fate of Erythrocytes Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Unable to divide, grow, or synthesize proteins  Wear out in 100 to 120 days  When worn out, are eliminated by phagocytes in the spleen or liver  Lost cells are replaced by division of hemocytoblasts

Control of Erythrocyte Production Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Rate is controlled by a hormone (erythropoietin)  Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood  Homeostasis is maintained by negative feedback from blood oxygen levels

Control of Erythrocyte Production Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 10.5

Quick Quiz Where are blood cells made? What is a hemocytoblast?