Circulatory System: Disease of Blood

 

Circulatory System: Disease of Blood

Blood

Blood is a red coloured liquid that flows in the blood vessels in the whole body. It is a liquid that contains cells. One of its important features is that it remains in liquid form as long as it is within blood vessels which are intact. But it clots as soon as it comes out of injured blood vessels. 

This prevents excessive blood loss after any injury. Human body has blood of volume about 1/12 the body mass i.e. about 5 liters. Out of that, about 55% is plasma and 45% is cells. The blood volume is maintained due to the osmotic  pressure between the blood vessels and plasma.

 

                                                  Components of blood

Component	Contents
Blood cells	.Red blood cells. .White blood cells. .Platelets.
Plasma	.water(99%). .Proteins(8%)             .Albumin.             .Globulin.              .Fibrinogen. .Electrolytes(0.9%)               .Sodium chloride.               .Sodium bicarbonate.               .Calcium.               .Phosphorous.               .Magnesium.               .Iron. .Organic compounds (0.1%)                .Glucose.                      .Fat.                      .Uric acid.                      .Creatinine.                      .Amino acids. .Gases                      .Oxygen.                      .Carbon dioxide.  .Hormones .Antibodies. .Enzymes.

 

 

Red blood cells

1.These are very small and biconcave disc-shaped.

2.There are 5000000 red cells per cmm.

3.Each cell has an outside covering and it contains haemoglobin. Haemoglobin combines with oxygen and forms oxyhaemoglobin, which circulates all over the body to supply oxygen to tissues. Haemoglobin level is 12.5g to 14g% in a woman and 14g to 16g% in a man. 14.5g% IS considered to be 100%.values above 90%are considered normal.

4.Red blood cells are produced in flat bones, ends of long bones, and small bones, in a tissue called red bone marrow. The following of red blood red blood cells.

                       .Iron.

                       .Folic acid.

                       .Vitamin B12.

                       .Proteins.

5.Life span of a red blood cell is about cell is about 120 days.

6.Dead red cells are removed in the spleen. The cells are broken down, and their iron and amino acids are used again.

 

White blood cells

1.These cells are colorless. They are bigger than red cells.

2.There are 6000 to 11000 white blood cells per cmm.

3.The functions of white blood cells are as follows:-

           . Protection of the body from infection.

                      .Granulocytes phagocytosed bacteria.

                      .Monocytes phagocytes bacteria.

                      .Lymphocytes produce  antibodies.

                      .Neutrophils and monocytes phagocytose foreign bodies.

                      .Granulocytes break proteins down and help remove necrotic tissue.

            .Lymphocytes develop antibodies against chronic infections.

4.Various types of white blood cells are as shown in the following table:-

 

                                                White Blood Cells

Type	Cells
Granulocytes	.Neutrophil. .Eosinophil. .Basophil.
Agranulocyte	.Lymphocyte. .Monocyte.

 

 

 

Blood Plasma

Functions of various components of blood plasma are as follows:-

Component                           Functions

Albumin                                  .Maintain osmotic pressure and thereby the volume of the circulating blood.

                                                  .Carry different substances bound to it.

                                                   .Supply protein to the cellular plasma.

Globulin                                    .Protection from infections.

Fibrinogen                                 .Coagulation of blood.

 

Formation of Blood

Red blood cells

1.These are formed in the red bone marrow, found in the flat bones, and ends of long bones.

2.Each cell passes through a number of stages before becoming mature red blood cell.

3.Immature red cells are found only in the bone marrow, while mature red cells enter circulation. However in some diseases immature red cells may be found in circulation.

4.The following substances are require for formation of red blood cells.

                       .Iron.

                        .Folic acid.

                        .Vitamin B12: It is obtained from the diet. Articles  rich in it, are liver, mutton, milk, eggs ,and cheese.

6.Worms in stools

7.Medications

                .Salicylates.

                .Cytotoxic drugs.

                .Chloramphenicol.

8.Radiation therapy.

9.Occupation :Exposure to toxins.

10.Gastrointestinal disturbances

                   .Gastroenteritis.

                   .Malabsorption syndrome.

                    .Achlorhydria.

11.Bleeding tendency: Coagulopathies.

12.Bone pains.

13.Paresthesia in limbs: Nutritional deficiency.

 

The following points are noted in examination

1.Pallor:In conjunctiva, nails, tongue, Oral mucous membrane.

2.Skin

      .Pallor.

      .Dry and scaly in myxedema

3.Nails

           .Flat or spoon –shaped in iron deficiency anaemia.

           .Pallor.

4.Conjunctiva

           .Pallor.

           .Icterus in case of hemolytic   anaemia.

5.Mouth

            .Pallor.

            . Smooth tongue in  pernicious anaemia.

            . Gingival hypertrophy in leukemia.

            .  Stomatitis in Megaloblastic anaemia.

6.Abdominal examination

             .Splenomegaly in hemolytic  anaemia and   leukemia.

              .Hepatomegaly.

7.Per rectal examination.

8.Bones.

Investigations

1.Haemoglobin.

2.Haematocrit.

3.RBC count.

4.WBC count.

5.Blood indices: mean corpuscular volume, mean corpuscular haemoglobin concentration.

6.Bone marrow examination.

7.Haemoglobin  electrophoresis.

8.Stools examination: Worms, occult blood.

9.Fractional test meal.

10.Barium meal.