1. BLOOD

2. BLOOD AND ITS ASSOCIATED DISORDERS
Blood is a specialized body fluid that circulates in the blood vessels bringing oxygen and nourishment to all the cells and carrying away waste like carbon di oxide.
Composition of blood
Blood cells (45%) like Erythrocytes(RBC), Leucocytes(WBC) , Platelets(THROMOBOCYTES)
All blood cells are produced in the bone marrow (haematopoises) some mature in the lymphoid organs
Plasma (55%)– constitutes about 90% of water , remaining 10% contains nutrients, electrolytes, gases, albumin (protein), clotting factors, antibodies, enzymes and hormones .
Normal blood volume is 5 ltrs

3. Erthrocytes (red blood cells)
Major function is to carry oxygen to the tissues
Oxygen is bound to iron containing pigment called hemoglobin(imparts red color to the blood)
RBC are biconcave or disc shaped having no nucleus
There are 5 millions RBC per microlitre of blood
These cells die after 120 days

4. Leucocytes White blood cells (WBC) They have a prominent nuclei Types
Granulocytes- have visible granules
Agranulocytes - do not show any visible granules
Three types of granulocytes
Neutrophils- also called polymorphs (because of their various shaped nuclei)
Eosinophils
Basophils
Two types of agranulocytes
Lymphocytes
Monocytes

5. Relative percentage of WBC
Neutrophils %- responsible for bulk of immuno response. Main components of pus and responsible for its whitish colour.
Eosinophils – 1-3%- mediates allergic reactions, defense against parasites
Basophils – less than 1%- mediates allergic reactions
Lymphocytes %- renders immunity
Monocytes – 3-7%- help in immune system. (low monocyte is good and high indicates a problem in the patient)
TOTAL WBC COUNT= millions per litre

6. Platelets One of the process of hemostasis is called coagulation
Fragments of small cells called megakaryocytes
Formed in the bone marrow
Normal count – 150,000 to 350,000 per microliter of blood
Plays an important role in hemostasis- (prevention of blood loss)
One of the process of hemostasis is called coagulation
Platelets form a plug at the site of vessel injury and release some substances that react with coagulation factors and seal the wound
Coagulation factors are 12 in number
Final reaction in coagulation is conversion of fibrinogen to fibrin threads to form a clot

7. Blood groups
Human blood groups fall into four main groups- A ,B ,AB, O
Each group has a specific combination of antigen(on RBC cell membrane) and associated antibodies
Antigens are inherited while antibodies are acquired by 6 months of birth
Group A –antigen A ,anti-B antibody
Group B- antigen B,anti- A antibody
Group AB-antigen AB, no antibodies
Group O- has no antigens,has both anti-A &B antibodies
People with group O are universal donors as they lack antigens, while group AB are universal recipients as they lack antibodies

8. Clinical aspects of blood
I Anaemia
It is defined as condition characterised by low amount of hemoglobin in the blood
Anaemia can result from decreased RBC count or small cell size or little hemoglobin
Different types of anaemia
A. Anaemia due to decreased blood count
EG: Aplastic anaemia – results from bone marrow destruction causes - Drugs ,Radiation, Viruses ,Toxins, Bone marrow cancers
B. Nutritional anaemia (iron deficiency)
Results from deficiency of vitamin B12 or folate needed for RBC development
Causes - Poor diet ,pregnancy, low iron absorption

9. C. Pernicious anaemia- results from specific form of Vit B12 deficiency
D. Sideroblastic anaemia- results from non utilisation of iron inspite of availability, secondary to any disease
E. Hemolytic anaemia- reduction in RBC due to excessive destruction of RBC. Congenital spherocytosis

10. F. Anaemia due to loss or destruction of RBC
Hemorrhagic anaemia – results from excessive blood loss-acute or chronic
Thalassemia –(thalassa means sea) occurs in mediterranian population
It is a heriditary disorder characterised by production of abnormal hemoglobin
G. Sickle cell anaemia- is a mutation altering the hemoglobin molecule resulting in sickle shape of the RBC .

11. II Hemophilia
Hereditary deficiency of clotting factor (factor viii)
Sex linked that passes from mother to son
There is presence of bleeding in the tissue
Can be treated with administration of required fractions of clotting factors

12. Neoplasms A. Leukaemia – It is the neoplasm of WBC.
White cells divide rapidly and accumulate but are incompetent
Symptoms
Anaemia, fatigue, bleeding,splenomegaly, hepatomegaly
B. Multiple myeloma
Cancer of blood forming cells in the bone marrow, mainly plasma cells that produce antibodies
Patient with multiple myeloma suffers from infections due to immunodeficiency
Treated with radiation and chemotherapy