临床检验基础(血液检查英语版)

Introduction to Practical Haemmatology Introduction:-

In the past humankind know about presence of blood, but a few centuries back science discovered that this blood circulates in our body. In Greek, Roman, and Unani medicine describe some disease due to blood abnormalities into: traumatic, inflammatory, infective, and neoplastic.

DEFINATION OF BLOOD:

Blood is highly specialized (sterile) connective tissues, which circulate in a closed system of vessels as a liquid with red coluor, but in out this system a solid phase will perform, which we called plug or blood clot.

Haematology: is the science that study the blood, and it's structure, function, disease, and the convenience between structure and the function.

BLOOD COMPONENT

Mainly we can divide blood into two parts:

1) Plasma 2) Blood cells.

The total amount of blood approximately 1/14 of the total body weight or 60-70 ml/ each kilogram of body weight.

Blood flows through every organ of the body providing effective communication between tissues.

PLASMA:

Plasma is a pale yellow fluid in which blood cells are suspended in.

Plasma forms about 55% of blood volume and composed of 95%or more water, and many solutes including proteins, minerals, ions, organic materials, hormones, enzymes, products of digestion, and waste products.

BLOOD CELLS:

1) Red blood cells (RBC).

2) White blood cells (WBC).

3) Platelets.

FUNCTION OF BLOOD:

□ Transportation and distribution:

- Oxygen transportation by haemoglobin from lungs to the tissues.

- Blood also can transport the nutrients absorbed by the digestive system to the tissues for use or storage.

- Hormones are carried from endocrine glands to the organs.

- Wastes are transported from tissues for excretion e.g.: carbon , dioxide, urea, createnine,…

□ Regulatory:

- Plasma maintain the PH. of blood (7.35-7.45), and in the tissues .

- Osmotic pressure in plasma is regulate by proteins and salts (sodium, chloride) to prevent excessive loss of fluids from the blood into tissues.

- Regulation of the body temperature.

□ Protective:

- Platelets and coagulation factors control the blood loss by thrombous formation.

- Leukocytes defend and produce antibodies and toxin against infection and tumor cells.

HAEMATOPOIESIS:

In normal healthy person there is a constant break down and new formation of cells, and the procedure of blood cells formation called Haematopoiesis.

NORMAL SITES OF BLOOD FORMATION:

- Fetus:

* Less than 2 months: in Yolk sac.

* 2-7 months: in the liver and a few in the spleen.

* Full term: in bone marrow for RBC, PLTs, and granulocytes, but lymphocytes and monocytes occures in spleen, lymph nodes and lymphoid tissues (liver and bone marrow with less numbers).