Hematology Lesson 1: Blood Formation and Components 47 Hematology Lesson 1: Blood Formation and Components

Lesson Objectives Upon completion of this lesson, students should be able to … Define and spell the terms to learn for this chapter. List the components of blood, including the liquid and cellular portions and functions of each.

Blood Formation and Blood Components Hematopoiesis: formation of blood cells Blood cells originate from the hematopoietic stem cell, but mature into one of seven individual types of cells

Critical Thinking Question Where does hematopoiesis primarily occur in adults?

Blood Red blood cells (erythrocytes) White blood cells (leukocytes) – five types: Granular leukocytes (have granules in their cytoplasm) Neutrophil Eosinophil Basophil 5

Blood Nongranular leukocytes (do not have granules in their cytoplasm) Lymphocyte Monocyte Platelets (thrombocytes) 6

Red Blood Cells Formed in bone marrow Contain hemoglobin Formation controlled somewhat by erythropoietin

Function of Hemoglobin Carry oxygen from the lungs to the cells of the body Carry carbon dioxide (a waste product) from the body back to the lungs, where it can be expelled with exhalation When hemoglobin is carrying oxygen, it is called oxyhemoglobin When it is carrying carbon dioxide, it is called carboxyhemoglobin

Red Blood Cells Last for about 4 months and are continuously being reproduced in the body The normal RBC range for a male adult is 4.5 to 6 million/mm3 The normal female RBC range is 4 to 5.5 million/mm3

White Blood Cells Also known as leukocytes Produced in bone marrow from stem cells Divided into several different types Originate in the bone marrow from stem cells Larger than RBCs Principal function is to defend against infection The range of WBCs in an adult is 4.5 to 11 thousand/mm3

Leukocyte Classification Granular Leukocytes (have granules in their cytoplasm) Neutrophils: Important for phagocytosis Eosinophils: Destroy parasites and increase during allergic reaction Basophils: Release histamine and heparin to damaged tissue 11

Leukocyte Classification Nongranular leukocytes (do not have granules in their cytoplasm) Lymphocytes: Provide protection through immunity Monocytes: Important for phagocytosis 12

Five Types of White Blood Cells

Neutrophils Divided into two categories: segmented neutrophils and nonsegmented neurophils Named this because the granules are neutral in color on the laboratory-stained slide The body reproduces neutrophils on an ongoing basis, and they only survive for a few days 14

Neutrophils Reproduction is increased when bacterial infection is occurring Neutrophils combat infection by phagocytosis Phagocytosis is the process in which the neutrophil surrounds, swallows, and digests the bacteria 15

Eosinophils Also assumed to be produced by the bone marrow Detection of a large number of eosinophils can indicate a parasitic condition or the presence of certain allergic conditions Have granules that produce a red color on the laboratory-stained slide Are called this due to the stain eosin, which is used in the staining of blood smears 16

Basophils Thought to be produced by the bone marrow Produce heparin – a substance that prevents clotting Increased amounts may be found in patients who have had their spleen removed Patients who have had excessive exposure to radiation may also have increased basophils 17

Basophils Contain the vasodilator histamine Appear in tissues where an allergic reaction is occurring Concentration of basophils may contribute to the severity of allergic reactions 18

Lymphocytes Produced in the bone marrow and in lymphoid tissue such as the spleen and lymph nodes Produce antibodies against foreign substances such as bacteria, viruses, and pollens 19

Lymphocytes Are small and large and can proliferate into B and T cells B cells may convert into plasma cells, which produce antibodies T cells can produce helper cells, cytotoxic cells, and suppressor cells To diagnose an individual with HIV, testing is performed to evaluate the type and amount of T cells present Lymphocytes do not have granules and are nonsegmented 20

Monocytes Formed in the bone marrow from stem cells Assist in phagocytosis Ingest foreign particles or bacteria that the neutrophils are unable to digest Assist in cleaning up cellular debris that may have been left from the infection An increase in monocytes is seen in patients who have certain diseases such as tuberculosis, typhoid, and Rocky Mountain spotted fever 21

Platelets (Thrombocytes) Smallest of all blood cells Formed in the bone marrow Main function is to assist in the clotting of blood Typically between 150,000 and 400,000 platelets/mm3 Increase around an area that is bleeding to assist in the formation of clots Leads to formation of thrombin, which converts fibrinogen to fibrin 22

Liquid Blood Formation and Components Plasma – liquid component of blood Plasma transports substances in blood through the body Water makes up 90 percent of plasma 10 percent of plasma is solutes Plasma is about 55% of the total blood.

Solutes in the Plasma Plasma proteins (albumin, globulin, fibrinogen, and prothrombin) Electrolytes, also called ionic solutions because they contain free ions (sodium, potassium, and chloride) Glucose Amino acids Lipids and carbohydrates

Solutes in the Plasma Metabolic waste products (urea, lactic acid, uric acid) Creatinine Respiratory gases (oxygen and carbon dioxide) Miscellaneous substances (hormones, antibodies, enzymes, vitamins, and mineral salts)

Formed Elements of Blood 26

The Function of Blood Transportation Protection Transports oxygen and nutrients Removes carbon dioxide from body Transports waste to the liver, kidneys, and skin for elimination

Questions? 28