Dr. Muhsin S. Ghalibpathophysiologist

Clinical Lab. Training

5TH Stage

Hematology

Introduction

Physical features

Composition

Hematological tests

-collection blood

-routine hematological tests in hospitals

Electronic hematology analyzers

Commonly used anticoagulants

Hematology

Hematopoiesis – the generation of blood cellsthat proceeds mainly in the bone marrow -is a well-controlled process constantlyoccurring throughout the live of themammalian organism.

BLOOD CELLS

Three types of cells are present in the blood

1. Red blood cells or erythrocytes

2. White blood cells or leukocytes

3. Platelets or thrombocytes.

Physical features.

The blood is denser and more viscous than water,slightly alkaline, sticky to touch, and salty intaste.

It clots on standing, leaving behind serum.

The normal total circulating blood volume amountsto 8% of the body weight, i.e. 5–6 liters in anaverage adult male weighing 70kg, and 4–5 litersin a female.

COMPOSITION OF BLOOD

Blood consists of 55% of watery liquidplasma that contains various proteins andother solutes dissolved in it.

The rest 45% is the formed elements—mainly the red blood cells (RBCs) but alsowhite blood cells (WBCs), and platelets(cell fragments).

COMPOSITION OF BLOOD

The RBCs are the most numerous (4.5–5.5million/mm3) and are medium sized (7–8μm).

Next in number are platelets (2.5–4.5lacs/mm3) and are the smallest (2–4 μm) insize. The WBCs number 4000–11000/mm3and vary in size from 8 to 20 μm.

The percentage of whole blood that is red cellsis called hematocrit, its value being 45.

Hematological tests

Mentions and indications one bloodtests in hospital?

(routine tests)

How can collection of blood samples

plasma

~55% of the volume

straw colored liquid on top

formed elements - ~45% of the volume

red blood cells

buffy coat - white blood cells and platelets

Collection of blood samples

1. AsepsisA. Sterilization of equipmentB. Cleaning/sterilizing of skinC. Prevention of contamination.2. The blood sampleThe term “blood sample” refers to the small amount of

blood—a few drops or a few milliliters—obtainedfrom a person for the purpose of testing orinvestigations.

-For a sample of whole blood or plasma- For a sample of serum.3. Commonly used anticoagulants

The routine blood tests

1-Blood film

2-Estimation of Hemoglobin(Hb g/dl)

3- The red blood cells count (RBCs)

4-Packed Cell Volume; PCV

5-Normal blood standards

The Total Leukocyte Count(TLC)

White Cell Count (WCC)

What is the normal total leukocyte count?

What is the difference between differential leukocyte

count and absolute leukocyte count?

What are the various types of leukocytes and what

are their functions?

What is meant by the terms leukocytosis and granulocytosis?

Name the physiological and pathological conditions

which cause leukocytosis.

What is leukemia and what are its major types?

Leukemias is a group of malignant (dangerous)neoplasms (new growths) of WBC formingorgans— bone marrow and lymphoid tissue.There is an uncontrolled production and release ofmature and immature WBCs into the circulation.

The leukemias (commonly called blood cancers)may be myeloid (usually involving neutrophils)or lymphatic (involving lymphocytes), and acuteor chronic

Non-Hodgkin Lymphomas

Hodgkin Lymphoma

Physical eatures.

The blood is denser and more viscous than water,slightly alkaline, sticky to touch, and salty in taste.

It clots on standing, leaving behind serum.

The normal total circulating blood volume amounts to8% of the body weight, i.e. 5–6 liters in an averageadult male weighing 70kg, and 4–5 liters in a female.

Anemia

Anemia is the blood disorder, characterized by the reductionin:

1. Red blood cell (RBC) count

2. Hemoglobin content

3. Packed cell volume (PCV).

Generally, reduction in RBC count, hemoglobin content andPCV occurs because of:

1. Decreased production of RBCs

2. Increased destruction of RBC

3. Excess loss of blood from the body.

All these incidents are caused either by inherited disorders orenvironmental influences such as nutritional problem,infection and exposure to drugs or toxins.

Classification of Anemia

Anemia is classified according to:

1. Morphological classification

2. Etiological classification.

Morphological classification depends upon the

size and color of RBC. Size of RBC is

determined by mean corpuscular volume

(MCV). Color is determined by mean

corpuscular hemoglobin concentration

(MCHC).

Morphological classification

1. Normocytic Normochromic Anemia

Size (MCV) and color (MCHC) of RBCs are normal. Butthe number of RBC is less.

2. Macrocytic Normochromic Anemia

RBCs are larger in size with normal color. RBC count isless.

3. Macrocytic Hypochromic Anemia

RBCs are larger in size. MCHC is less, so the cells are pale(less colored).

4. Microcytic Hypochromic Anemia

RBCs are smaller in size with less color

Etiological Classification

On the basis of etiology (study of cause or origin),

anemia is divided into five types:

1. Hemorrhagic anemia (blood loss anemia)

2. Hemolytic anemia

3. Nutrition deficiency anemia

4. Aplastic anemia

5. Anemia of chronic diseases.

I-Hemorrhagic anemia

It refers to excessive loss of blood. It occurs both in acuteand chronic hemorrhagic.

Acute hemorrhage refers to sudden loss of a large quantityof blood as in the case of accident. Due to severehemorrhage.

Plasma volume is replaced rapidly by the fluids present intissue spaces. This leads to marked dilution of the blood.

RBCs are replaced within 4-6 weeks.

However, morphologically the RBCs are normocytic andnormochromic. Decreased RBC count causes hypoxia,which stimulates the bone marrow to produce morenumber of RBCs.