HAEMATOPOETIC SYSTEM

Group 7 B

What is Hematology?

Hematology is the study of blood in health and disease. It includes problems with the red blood cells, white

blood cells, platelets, blood vessels, bone marrow, lymph nodes, spleen, and the proteins involved in bleeding and clotting (hemostasis and thrombosis).

A hematologist is a medical doctor who applies this specialized knowledge to treat patients with blood conditions.

The Components of Blood and Their Importance

PLASMA

• The liquid component of blood • A mixture of water, sugar, fat, protein,

and salts. • The main job of the plasma is to

transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones, and proteins that help maintain the body's fluid balance.

RED BLOOD CELL ( ERYTROCYTE) Known for their bright red color, the most abundant cell in the blood, accounting for

about 40-45 percent of its volume. The shape of a red blood cell is a biconcave (a red blood cell looks like a donut). Production of red blood cells is controlled by erythropoietin, a hormone produced

primarily by the kidneys. Red blood cells start as immature cells in the bone marrow and after approximately

seven days of maturation are released into the bloodstream. red blood cells have no nucleus and can easily change shape, helping them fit through

the various blood vessels in your body. a red blood cell more flexible, it also limits the life of the cell as it travels through the

smallest blood vessels, damaging the cell's membranes and depleting its energy supplies. The red blood cell survives on average only 120 days.

Red cells contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled.

WHITE BLOOD CELL ( LEUKOCYTE)

White blood cells protect the body from infection. Accounting for about 1 percent of your blood.The most common type is the neutrophil the "immediate response"

cell 55 to 70 percent of the total white blood cell count..The other major type of white blood cell is a lymphocyte. Two main populations of these cells :1. T lymphocytes help regulate the function of other immune cells

and directly attack various infected cells and tumors. 2. B lymphocytes make antibodies, which are proteins that

specifically target bacteria, viruses, and other foreign materials.

PLATELETS ( THROMBOCYTE)• Platelets are not actually cells but rather small fragments of cells. • Platelets help the blood clotting process (or coagulation) by gathering

at the site of an injury, sticking to the lining of the injured blood vessel, and forming a platform on which blood coagulation can occur.

• This results in the formation of a fibrin clot, which covers the wound and prevents blood from leaking out. Fibrin also forms the initial scaffolding upon which new tissue forms, thus promoting healing.

• A higher than normal number of platelets can cause unnecessary clotting, which can lead to strokes and heart attacks;

• Conversely, lower than normal counts can lead to extensive bleeding.

HAEMATOLOGIC DISORDER

1. ANEMIA2. BLEEDING DISORDER3. BLOOD CANCER

1. ANEMIA• Anemia occurs when you do not have

enough red blood cells or when your red blood cells do not function properly.

• It is diagnosed when a blood test shows a hemoglobin value of less than 13.5 gm/dl in a man or less than 12.0 gm/dl in a woman.

• Symptoms: Weakness Shortness of breath Dizziness Fast or irregular heartbeat Pounding or "whooshing" in your ears Headache Cold hands or feet Pale or yellow skin Chest pain

Etiology : Poor diet, intestinal disorders, chronic diseases, infections, and other conditions (s.a. woman on mesruation)

Common type of anemia :o Iron-deficiency anemia o Anemia and Pregnancy o Sickle cell anemiao Anemia caused by other diseaseso Hemolytic anemia o Aplastic anemia o Vitamin-deficiency anemia

 2. Bleeding Disorders

• A group of conditions that result when the blood cannot clot properly

• In normal clotting, platelets, a type of blood cell, stick together and form a plug at the site of an injured blood vessel.

• Bleeding can result from either too few or abnormal platelets, abnormal or low amounts of clotting proteins, or abnormal blood vessels.

1. Hemophilia is perhaps the most well-known inherited bleeding disorder, although it is relatively rare. It affects mostly males.

2. Von Willebrand disease, the most common inherited bleeding disorder in America caused by clotting proteins. Von Willebrand disease can affect both males and females. Platelet disorders are the most common cause of bleeding disorder and are usually acquired rather than inherited.

3. BLOOD CANCER Blood cancers affect the production and function of your blood cells. Most of these cancers start in your bone marrow where blood is produced. Stem cells in your bone marrow mature and develop into three types of blood

cells: red blood cells, white blood cells, or platelets. In most blood cancers, the normal blood cell development process is interrupted

by uncontrolled growth of an abnormal type of blood cell. These abnormal blood cells, or cancerous cells, prevent your blood from

performing many of its functions, like fighting off infections or preventing serious bleeding.

Three common types : 1. Leukemia2. Lymphoma3. Myeloma

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