BLOOD PHYSIOLOGY Study Notes for Medical Students

Total circulating blood is 8% of total body weight
Active bone marrow forming the blood cells is called red marrow and inactive marrow is called yellow marrow. Inactive marrow is filled with fats.
75% bone marrow belongs to white blood cells producing myeloid series
Neutrophils and monocytes are produced from a single precursor. There are se[arate pools for progenitors of megakaryocytes, lymphocytes, erythrocytes, eosinophils, and basophils
Mast cells, Kupfer cells, dendritic cells, osteoclasts and Langerhans cells also originate from bone marrow
Best source of hematopoietic stem cells is umbilical cord blood
Average half life of neutrophils in circulation is 6 hours
Nutrophils, eosinophils, and basophils are collectively called granulocytes/polymorphonuclear cells
Eosinophils are abundant in GIT and respiratory mucosa
Mast cells are abundant in areas rich in connective tissue eg beneath epithelium
Monocyte leave the circulation and become macrophages in tissues. They do not reenter the circulation.
Pluripotent uncommitted stem cells become committed by the action of IL1, IL6 followed by IL3(I,3,6 commits the stem cells, kind of love guru )
Cytokines are hormone like molecules that act generally in paracrine fashion
IL1 increases slow wave sleep and reduces appetite
Platelets don’t have nuclei.They have half life of 4 days
Splenectomy causes an increase in circulation platelets.
Cytoplasm of platelets contains actin, myosin, glycogen, lysosomes, and two types of granules: a. Dense granules: they have nonprotein substances. They contain serotonin and ADP b. Alpha granules: contain clotting factors, PDGF
Platelet production is controlled by colony stimulating factor and thrombopoietin. Thrombopoietin controls the maturation of megakaryocytes and is produced by kidney and liver.
Osmotic fragility of RBC starts at 0.5% saline. Almost half the RBCs are lysed at 0.40 to 0.42% saline. Complete lysis occurs at 0.35% saline.
2.5 % hb in adults is HbA2
Hb F has the ability to decrease the polymerization of deoxygenated HbS. Hydroxyurea causes HbF production and is used in treatment of HbS
Blood group antigens are called aglutinogens
Blood group antibodies are called agglutinins
Blood group antigens are also present in salivery gland, saliva, kidney, pancrease, liver, lungs, testes, semen, and amniotic fluid
A and B antigens are actually oligosaccharides that differ in their terminal suger. In RBCs they are mostly OLIGOSPHINGOLIPIDS and in other tissues they are glycoprotiens.(past MCQ)
An antigen called H antigen is present in all RBCs in all individuals. In blood group A the A antigen is attached to H antigen, in blood group B the B antigen is attached to H antigen where as in blood group O no antign is attached to H antigen i.e terminal part of blood group O is H antigen(past MCQ). Blood group AB has both antigens at the terminal.
Bilirubin rarely penetrates Blood brain barrier in adults. But in neonates and fetus the BBB is permeable to it an in erythroblastosis feotalis it causes KERNICTERUS
If whole blood is allowed to clot and clot is removed, remaining is called serum. (plasma minus factor 2,5,8,fibrinogen is called serum)(past MCQ)
Serum has high serotonin level due to breakdown of platelets.
Thrombomodulin is produced by all endothelial cells except that of microcicculation of brain
Thrombin is procoagulant in circulation blood. It becomes anticoagulant when it binds to thrombomodulin
Lymph has lower protein content than plasma.
Blood Storage

Storage of different blood products

Whole blood is stored at 4° C for 3 weeks.
Packed cells (RBCs) are stored at 1-6° C for 35 days.
FFP (fresh frozen plasma) and cryoprecipitate can be stored at -40° C for 2 years.
Platelets are stored at 22° C for 5 days
mitral regurgitation =pansystolic murmur
mitral stenosis =mid diastolic murmur
aortic regurgitation =end diastolic murmur
aortic stenosis =ejection Systolic murmur
pulmonary regurgitation =diastolic murmur
pulmonary stenosis =Systolic murmur
throtoxicosis=innocent murmur
decrease hematocrit =continuous murmur
Gastric Motility increased by GASTRIN
Gastric Motility decreased by CCK
Intestinal Motility increased by CCK
Intestinal Motility decreased by SECRETIN
Gastric Emptying increased by Motilin
Gastric Emptying decreased by CCK
Gastric secretions inhibited by SECRETIN
If Newborn to 14 years of age the most common cause is acute lymphoblastic leukemia
If age is between 40 to 60 most likely cause will be AML and CML
If age is more than 60 most likely causes r CLL and CML.
Repeated blood Transfusion…..HAEMOCHROMATOSIS
Multiple Transfusions….HYPOCALCEMIA
Massive Transfusion. ….HYPERKALEMIA, HYPOCALCEMIA, and HYPOTHERMIA
-Eosinophilia present in:
Hodgkin lymphoma and polyarteritisnodosa.
-PGI2__by endothelial cells
-TXA2__by platelets
Blood transfusion induced electrolyte balance is as follows:
-hypocalcemia
-hyperkalemia
-hypothermia
-metabolic acidosis
-left shift of oxy-hem curve