(relates to chapter 30, “nursing assessment: hematologic system,” in the textbook) copyright ©...

(Relates to Chapter 30, “Nursing Assessment: Hematologic System,” in the textbook)

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

• Hematology Study of blood and blood-forming tissues▪ Bone marrow▪ Blood▪ Spleen ▪ Lymph system

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. 2

• Hematopoiesis: Blood cell production Occurs within the bone marrow Bone marrow produces red blood cells (RBCs), white blood cells (WBCs), and platelets.

Three types of cells develop from nondifferentiated immature blood cells in the bone marrow, called stem cells.



Fig. 30-1. Development of blood cells. RBCs, Red blood cells; WBCs, white blood cells.

• Bone marrow Soft material that fills the central core of bones

Two types of bone marrow▪ Yellow: Adipose▪ Red: Hematopoietic


• Red marrow Produces blood cells In adults, found in flat and irregular bones such as the ends of long bones, vertebrae, sacrum, sternum, ribs, flat cranial bones, and scapulae


• Blood Classified as a type of connective tissue that performs three functions▪ Transportation ▪ Regulation▪ Protection


Three functions of blood1. Transportation

▪ Oxygen from lungs to cells▪ Nutrients from GI tract to cells▪ Hormones from endocrine

glands to cells▪ Metabolic wastes from cells to

lungs, liver, and kidneys


Three functions of blood2. Regulation

▪ Fluid and electrolyte balance ▪ Acid-base balance▪ Body temperature


Three functions of blood3. Protection

▪ Combats invasion of pathogens and other foreign substances

▪ Maintains homeostasis of blood coagulation



Fig. 30-2. Approximate values for the components of blood in the adult. Normally, 45% of the blood is composedof blood cells, and 55% is composed of plasma.

• Plasma constitutes 55% of blood.

▪ Composed primarily of water but also contains proteins, electrolytes, gases, nutrients, and waste products


• Blood cells make up 45% of blood.

▪ Three types of blood cells▪ Erythrocytes (RBCs)▪ Leukocytes (WBCs)▪ Thrombocytes (platelets)


• Primary functions of blood cells Erythrocytes (RBCs): Transportation of gases and assistance in maintaining acid-base balance

Leukocytes (WBCs): Protection from infection

Thrombocytes (platelets): Promote blood coagulation in response to injury


• Erythrocytes (RBCs) Flexible cell wall able to alter shape to pass through small capillaries

Biconcave shape and thin cell wall facilitate the diffusion of gases.

Primarily composed of hemoglobin, a complex protein–iron compound that binds with oxygen and carbon dioxide


• Leukocytes (WBCs) Appear white when separated from blood

Originate from stem cells within bone marrow

Two categories of leukocytes are granulocytes (three types) and agranulocytes (two types).

Five different types of leukocytes, each with a different function


TYPE CELL FUNCTIONGranulocytes Neutrophil Phagocytosis, early phase of inflammation

Eosinophil Phagocytosis, parasitic infection

Basophil Inflammatory response, allergic response

AgranulocytesLymphocyte Cellular, humoral immune response

Monocyte Phagocytosis, cellular immune response


• Granulocytes: Contain granules within the cytoplasm Neutrophils: Most common form, with 50% to 70% of all leukocytes being neutrophils

Eosinophils: Only 2% to 4% of all leukocytes

Basophils: Less than 2% of all leukocytes


• Agranulocytes: Do not contain granules within the cytoplasm and are also called mononuclear cells because they have one discrete nucleus Lymphocytes: Make up 20% to 40% of leukocytes

Monocytes: Account for approximately 4% to 8% of all leukocytes


• Granulocytes Neutrophils

▪ Primary function is phagocytosis.▪ Primary phagocytic cells involved in acute inflammatory response

▪ Mature neutrophil is segmented (“seg”), with multiple segments in its nucleus.


• Granulocytes Neutrophils (cont'd)

▪ Immature neutrophils are called bands (for the nonsegmented appearance of the nucleus).

▪ Mature neutrophils are more efficient phagocytes than bands.


Normal segmented neutrophil.Normal segmented neutrophil.


• Granulocytes Neutrophils (cont'd)

▪ First at site of infection▪ An increase in percent of bands is called a shift to the left, meaning the bone marrow is releasing less-mature cells into circulation in response to a site of injury (increased in acute infection and inflammation).

▪ Life span: 2 to 14 days


• Granulocytes Eosinophils

▪ Account for only 2% to 4% of all WBCs

▪ Have a reduced ability for phagocytosis compared with neutrophils

▪ Granules contain histamine.▪ Engulf antigen-antibody complexes formed during an allergic response


• Granulocytes Eosinophils (cont'd)

▪ Defend against parasites▪ Found in large numbers in lungs and GI tract


Eosinophil on Wright’s stained slide.Eosinophil on Wright’s stained slide.


• Granulocytes Basophils

▪ Make up less than 2% of all leukocytes

▪ Limited role in phagocytosis ▪ Have cytoplasmic granules that contain heparin, serotonin, and histamine

▪ When stimulated by an antigen, basophils release their granules.


Basophils on Wright’s stained slides.Basophils on Wright’s stained slides.

Note normal RBC on slide on right and hypochromic Note normal RBC on slide on right and hypochromic (low hemoglobin) RBC on slide on left.(low hemoglobin) RBC on slide on left.


• Agranulocytes Lymphocytes

▪ Form the basis of cellular and humoral immune responses

▪ Two subtypes of lymphocytes are B cells and T cells.


• Agranulocytes Monocytes

▪ Potent phagocytic cells ▪ Second type of cell to arrive at site of injury

▪ When monocytes migrate into tissue, they become macrophages.


Lymphocyte on Wright’s stained slide.Lymphocyte on Wright’s stained slide.


Monocyte on Wright’s stained slide.Monocyte on Wright’s stained slide.


• Macrophages: Monocytes that have migrated into tissue Resident macrophages

▪ Called Kupffer cells when in liver▪ Called osteoclasts when in bone▪ Called alveolar macrophages when in lung


• Primary function is to initiate clotting process by producing plug at site of injury.

• Thrombocytes are released into circulation by cells in the bone marrow called megakaryocytes.


• Have a life span of only 5 to 9 days

• Participate in clot shrinkage and retraction


• Normal blood clotting mechanisms minimize blood loss after injury.

• Four components of normal hemostasis

1.Vascular response2.Platelet plug formation3.Development of fibrin clot on

platelet plug by plasma clotting factors

4.Lysis of clot Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. 37

• Vascular response Immediate local vasoconstrictive response of injured blood vessels▪ Reduces leakage of blood from the injured vessel by reducing vessel size

▪ Vasoconstriction gives time for platelet response and plasma clotting factors to be triggered.


• Platelet plug formation Activated by exposure to interstitial collagen from the injured blood vessel

Platelet stickiness is called adhesiveness.

Formation of clumps is termed aggregation or agglutination.

Platelets facilitate the reactions of the plasma clotting factors.



Fig. 30-4. Coagulation mechanism showing steps in the intrinsic pathway and extrinsic pathway as it would occurin the test tube. HMWK, High-molecular-weight kininogen; RBCs, red blood cells.

• Plasma clotting factors Form a visible fibrin clot on the platelet plug

Are labeled with both names and Roman numerals

Are always present in circulation in inactive forms until stimulated to initiate clotting through one of two pathways


• Plasma clotting factors (cont'd) Two pathways of clotting

▪ Intrinsic pathway is activated by collagen exposure.

▪ Extrinsic pathway is initiated when tissue factor or tissue thromboplastin is released from injured tissue.


• Plasma clotting factors (cont'd) Thrombin is the most powerful enzyme in the coagulation process because it converts fibrinogen to fibrin, an essential component of a blood clot.


• Lysis of clot Anticoagulation, the reverse of clotting, helps keep blood fluid.

Anticoagulation occurs by two means.▪ Antithrombins: Interfere with thrombin

▪ Fibrinolysis: Process that results in dissolution of the fibrin clot



Fig. 30-5. Fibrinolytic system.

• Located in the upper left quadrant next to kidney

• Functions can be classified as Hematopoietic: Able to produce RBCs during fetal development


• Functions (cont'd) Filtration

▪ Removes old and damaged RBCs from circulation

▪ Removes hemoglobin from RBCs and returns iron component to the bone marrow for reuse

▪ Filters out bacteria, especially encapsulated organisms


• Functions (cont'd) Immunologic: Contains a rich supply of lymphocytes, monocytes, and stored immune globulins

Storage: Stores RBCs and approximately 30% of total mass of platelets


• Consists of Lymph fluid Lymphatic capillaries Lymphatic ducts Lymph nodes


• Protein and fat from the GI tract and certain hormones are returned to circulatory system.

• Returns excess interstitial fluid to the blood to prevent or reduce edema


• Lymph fluid Pale yellow interstitial fluid that has diffused through capillary walls

Circulates through special vasculature

Too much interstitial fluid or reduced absorption leads to lymphedema ▪ May occur as a complication of mastectomy or lumpectomy


• Lymphatic capillaries Thin-walled vessels with irregular diameter

Larger than blood capillaries but without valves


• Lymphatic capillaries (cont’d) Unite to form lymphatic vessels that carry all lymph fluid to the right lymphatic duct or the thoracic duct

These larger vessels drain into subclavian veins in the neck.


• Lymph nodes Small clumps of lymphatic tissue found in groups along lymph vessels at various sites

More than 200 lymph nodes throughout the body

Largest concentration of lymph nodes is in the abdomen surrounding the GI tract.


• Lymph nodes (cont'd) Primary function is filtration of pathogens and foreign particles carried by lymph fluid.

Located both superficially and deep


• Liver Acts as a filter Produces all the procoagulants essential for hemostasis and blood coagulation

Stores excess iron Produces hepcidin, a key regulator of iron balance


While reviewing the results of a 76-year-old patient’s complete blood count (CBC), which of the following findings would be of greatest concern to the nurse?

1. Platelets of 400,000/μL2. Hemoglobin of 11.4 g/dL 3. White cell count of 3000/μL4. Red cell count of 4.5 × 106/μL

Audience Response Question


To evaluate the effectiveness of treatment for a patient with thrombocytopenia, the nurse plans to monitor the:

1. Platelet count.2. Prothrombin time.3. Partial thromboplastin time.4. International normalized ratio (INR).

Audience Response Question


(relates to chapter 30, “nursing assessment: hematologic system,” in the textbook) copyright ©...

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