Zhikal O. Khudhur/Assist lecturer_____________________________________________Hematology– 3rd Stage /1st Semester

zhikal.omer@tiu.edu.iq https://tiu.edu.iq/

2021 - 2022

TIU - Faculty of ScienceMedical Analysis Department

Lec. 1: Hematology

Introduction, short history, role of blood,composition of blood

Hematology: the study of the physiology of the blood•

• Hematology: is the branch of medicine concerned with the study of the cause,

prognosis, treatment, and prevention of diseases related to blood.

• Hematology is the science or study of blood, blood-forming organs, and blood

diseases.

• Blood: Nutritive fluid that circulates through the circulatory system to supply

oxygen and nutrients

• Blood is a fluid connective tissue, a variety of specialized cells that circulate in a

watery fluid containing salts, nutrients, and dissolved proteins in a liquid

extracellular matrix. Blood contains formed elements derived from bone marrow

History of Blood1288: Small Circulatory System by Ibn Alnafis

1492: The first reported blood transfusion occurred (three healthy individuals to

Pop Innocent VII).

1578: Large Circulatory System by William Harvey

1628: William Harvey, an English physician discovered how blood circulated

1665: The first successful blood transfusion was recorded (dog toanother).

1666 : RBC by Marcello Malpighi

1667: Richard Lower and Jean-Baptiste Denis reported successful transfusions from animals to humans.

1795: Syng Physick did the first successful blood transfusion from onehuman to another human in America.

1818: The first successful transfusion was recorded (husband to his wife)

1843: WBC by Gabriel Andral

1882: Platelets by Giulio Bizzozero

1899: Leukemia by Maj. Samuel T. Armstron

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Karl Landsteinerthree human blood groupsTwo students ABO blood group system.

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1902:

1903: George Washington Crile started to use blood trasnfusionregularly in surgery.

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1909, cross-matching of blood.

1910: Anemia noted by Herrick

1912:Roger Lee defined the terms ‘Universal donor’‘Universal recipient1914: As mentioned earlier, several anticoagulants

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• 1916:Francis Rous and J.R. Turner introduced a citrate-glucose solution, which was added to the collected blood.

1925:While Karl Landsteiner was working in New York he discovered two more blood group systems, the MN and the P blood group systems.

1926: The British Red Cross instituted the first human blood transfusion service in the world.

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Functions• Transports

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Dissolved gases (e.g. oxygen, carbon dioxide)

Waste products of metabolism (e.g. water,

ammonia, urea, uric acid, and creatinine, Lactic

acid..)

Hormones

Enzymes

Nutrients (such as glucose, amino acids, micro-nutrients (vitamins & minerals), fatty acids, glycerol)

Plasma proteins (associated with defence, such a

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–blood-clotting and anti-bodies)

Blood cells (incl. white blood cells , and red–blood cells ).

Maintains Body

body temperature

normally fluctuates

within a degree of37.0° C (98.6° F).Maintainingappropriate bodytemperature by absorbing and distributing heat throughout the bodyand to the skin surface toencourage heat loss.

Temperature

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Controls pH• Maintaining normal pH in body tissues. Many blood proteins

and other bloodborne solutes act as buffers to prevent excessive or

abrupt changes in blood pH that could jeopardize normal cell

activities. Additionally, blood acts as the reservoir for the body’s

“alkaline reserve” of bicarbonate atoms. The pH of blood must

remain in the range 6.8 to 7.4, otherwise it begins to damage

cells.(Acid-base Balance)

Removes toxins from the body• The kidneys filter all of the blood in the body , 36 times every

24 hours. Toxins removed from the blood by the kidneys leave the body in the urine. (Toxins also leave the body in the form ofsweat.)

Regulation of Body FluidElectrolytes

• Maintaining adequate fluid volume in the circulatory system. Salts

(sodium chloride and others) and blood proteins act to preventexcessive fluid loss from the bloodstream into the ECF. As a result, the fluid volume in the blood vessels remains ample to support efficientblood circulation to all parts of the body

• Preventing blood loss. When a blood vessel is damaged, platelets and plasma proteins

initiate clot formation, halting blood loss.

Preventing infection. Drifting along in blood are antibodies, complement proteins, and white blood cells, all of which help defend the body against foreign invaders such as bacteria andviruses.

Composition of Blood

If blood is spun in a centrifuge, 3 layers are formed:

1. Bottom Layer (= 45%)- The heavier formed elements are packed

down by centrifugal force.

Most of the reddish mass at the bottom is erythrocytes (RBCthat function in O2 transport).

2. Top Layer (55%)- The lighter plasma rises to the top

3. Buffy Coat (>1%) - Thin, whitish layer between the formed

elements layer and the plasma layer.

• Contains Leukocytes & Platelets

The cellular pathways ofhematopoiesis:

• cellular Organization of Hematopoiesis

• 1. Stem Cells:• Totipotential.

• Multipotential.

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Progenitor Cells.

Precursor Cells.

Effector Cells.

Stem Cell• These cells have extensive proliferative capacity

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Totipotent Stem Cells

Self Renewal, Pluripotency, Present in Marrow in SmallNumbers, Highly Resistant to Chemotherapy, Small numberscirculate in blood, Surface Antigen -CD34+ and Dysfunction

leukemialeads to aplastic anemia or certain types of

Q/ What arehemopoieticmicroenvironment?

Multipotent Stem Cells (Lymphoid andMyloid)•

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Produced from Totipotent Stem Cells

Able to self renewal, Differentiation(Ex:LymphoidMature Lymphosyte)

Lymphoid stem cell Lymphoproliferative Acute Lymphocytic lukemia)

Myeloid stem cell ??????

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Progenitor Cell (CFU)

•Derived from Multipotent•Committed stem cells lose theircapacity for self-renewal (limited).

• It is irreversibly committed

•Regulated by hormone or substanceto Proliferation and Maturation.

•CFU-GEMM, CDU-GE, CFU-GM, CFU-G

Precursor Cells -Blasts andtheir progeny

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First morphologically identifiable

Erythroblast -Red Cells.

Myeloblast -Granulocytes.

Monoblast –Monocytes.

Lymphoblast –Lymphocytes.

Megakaryoblast –Platelets.

cells:

Little if any self-renewal. Theof hematopoiesis:

cellular pathways

Mature Effector Cells

• Red Cells: carry oxygen, carbon dioxide;lifespan 120 days.

Neutrophils: phagocytosis, killing.

Lymphocytes: identify cells as self or non-self.

Monocytes: phagocytosis, killing, antigen presentation.

Platelets: hemostasis. The cellular pathwaysof hematopoiesis:

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Prenatal and neonatal hemopoiesis• Progressive hemopoiesis in these organs results from

in situ differentiation of circulating stem cells.

• The liver and spleen are inactive but retain potentialto revert to hemopoiesis in diseases of bone marrow