Blood Cells

1.Phagocytosis
2. Antibody formation by B cell
3. Immunity by T-cell, B cell,macrophage
4. Secretion of heparin by basophil and prevent intravascular blood coagulation 
5. Antihistamine action by eosinophil
6. Eosinophils kill parasites

Explanations: ‘O’ group has no antigen & AB group has no antibody.

Explanations:
Reticulocyte is otherwise known as immature RBC. It is slightly larger than matured RBC. The cytoplasm contains the reticular network or reticulum, which is formed by remnants of disintegrated organelles. Due to the reticular network, the cell is called reticulocyte. The reticulum of reticulocyte stains with supravital stain.

Explanations: Blood = Plasma (55%) + Formed elements (45%)

Explanations:
Hb S, Hb C, Hb H, Hb Barts are abnormal Hb.

Macrocytosis, i.e. an elevated MCV (>96fL) of which the causes can be seen in:
megaloblastic anaemia secondary to vitamin B12 and folic acid deficiency;
chronic alcoholism and/or alcoholic liver disease (most common causes of all causes of macrocytosis), pregnancy, hypothyroidism, reticulocytosis, aplastic anaemia, myelodysplastic syndromes and can also be caused by drugs that inhibit DNA synthesis (e.g. azathioprine);
an elevated MCV would suggest, along with the deranged LFTs, and support a diagnosis of alcoholic liver disease.

Explanations:
Eosinophils play an important role in the defence mechanism of the body against the parasites. During parasitic infections, there is a production of a large number of eosinophils which move towards the tissues affected by parasites. Eosinophil count increases also during allergic diseases like asthma.

Effects of Leukemia on the Body
The first effect of leukemia is metastatic growth of leukemic cells in abnormal areas of the body. Leukemic cells from the bone marrow may reproduce so much that they invade the surrounding bone, causing pain and, eventually, a tendency for bones to fracture easily.
Almost all leukemias eventually spread to the spleen, lymph nodes, liver, and other vascular regions, regardless of whether the leukemia originated in the bone marrow or lymph nodes.
Common effects in leukemia are the development of infection, severe anemia, and a bleeding tendency caused by thrombocytopenia (lack of platelets). These effects result mainly from displacement of the normal bone marrow and lymphoid cells by the nonfunctional leukemic cells.

Finally, an important effect of leukemia on the body is excessive use of metabolic substrates by the growing cancerous cells. The leukemic tissues reproduce new cells so rapidly that tremendous demands are made on the body reserves for foodstuffs, specific amino acids, and vitamins. Consequently, the energy of the patient is greatly depleted, and excessive utilization of amino acids by leukemic cells causes especially rapid deterioration of the normal protein tissues of the body. Thus, while the leukemic tissues grow, other tissues become debilitated. After metabolic starvation has continued long enough, this factor alone is sufficient to cause death.
Bibliography
David BA, Kubes P: Exploring the complex role of chemokines and chemoattractants in vivo on leukocyte dynamics Immunol Re

Explanations:
Monocyte & lymphocyte are mononuclear leukocytes.

Increased condensation and finally pyknosis of the nucleus

Erythropoietin is produced by interstitial cells in the peritubular capillary bed of the kidneys and by perivenous hepatocytes in the liver. It is also produced in the brain, where it exerts a protective effect against excitotoxic damage triggered by hypoxia; and in the uterus and oviducts, where it is induced by estrogen and appears to mediate estrogen-dependent angiogenesis.
The gene for the hormone has been cloned, and recombinant erythropoietin produced in animal cells is available for clinical use as epoetin alfa.
The recombinant erythropoietin is of value in the treatment of the anemia associated with kidney failure; 90% of the patients with end-stage renal disease who are undergoing dialysis are anemic as a result of erythropoietin deficiency. Erythropoietin is also used to stimulate red cell production in individuals who are banking a supply of their own blood in preparation for autologous transfusions during elective surgery (see Chapter 31).

Hematopoietic function of cortisol
·         BEL ↓ (basophil, Eosinophil, Lymphocyte)

·         PEN ↑ (Platelet, erythrocyte, neutrophil)

Morphology of RBC
Circular, non- nucleated, biconcave disc
● Diameter  7.8 micrometer
● Thickness   2.5 micrometer at thickest point and 1 micrometer or less in the center
● Surface area 140micrometer2
● Volume    90-95 micrometer3 
● Each RBC contains 29 pg of Hb

Folic acid acts as a catalyst in DNA synthesis.

Explanations:
In response to hypoxia kidney release erythropoietin that acts on bone marrow & stimulate erythropoiesis.

When RBCs are delivered from the bone marrow into the circulatory system, they normally circulate an average of 120 days before being destroyed. Even though mature RBCs do not have a nucleus, mitochondria, or endoplasmic reticulum, they do have cytoplasmic enzymes that are capa- ble of metabolizing glucose and forming small amounts of adenosine triphosphate.
These enzymes also do the following:
(1) maintain pliability of the cell membrane;
(2) maintain membrane transport of ions;
(3) keep the iron of the cells' hemoglobin in the ferrous form rather than the ferric form;
(4) prevent oxidation of the proteins in the RBCs.
Even so, the metabolic systems of old RBCs become progressively less active, and the cells become more and more fragile, presumably because their life processes wear out.

Transport processes for macromolecules:
this process also called- Functional system of cell
1.Exocytosis(Neurotransmitters,Hormones,Enzymes,Proteins)
2. Endocytosis
◆ Pinocytosis(cell drinking)-proteins,vitamins
◆ Phagocytosis(cell eating)-bacteria,dead cell, tissue debris.

Secondary Polycythemia
Whenever the tissues become hypoxic because of too little oxygen in the breathed air, such as at high altitudes, or because of failure of oxy- gen delivery to the tissues, such as in cardiac failure, the blood-forming organs automatically produce large quantities of extra RBCs. This condition is called secondary polycythemia, and the RBC count commonly rises to 6 to 7 million/mm³, about 30% above normal.

A common type of secondary polycythemia, called phys iological polycythemia, occurs in those who live at altitudes of 14,000 to 17,000 feet, where the atmospheric oxygen is very low. The blood count is generally 6 to 7 million/mm³, which allows these people to perform reasonably high lev- els of continuous work, even in a rarefied atmosphere.

Explanations:
Mean corpuscular haemoglobin value in range is 27-32pg & average 29pg.

Explanations:
Platelet has no nucleus.

Explanations: Agglutinogens are present on RBC membrane & agglutinins are present on serum.

Hypoxia (decreased level of oxygen in blood) stimulates kidney to secrete EPO.

When red cells become older(120days) and fragile, they are destroyed in reticulo-endothelial system. The main destruction occurs in the capillaries of red pulp of spleen because the splenic capillaries diameter is very small. So, spleen is called ‘graveyard of RBCs’.    

Explanations: Glycophorin & anion exchange protein are integral protein of RBC membrane protein.