BLOOD Flashcards
General functions of blood
• Transport O 2 , CO 2, nutrients, waste products, ions, hormones, and heat • Regulation : ion and PH balance • Defense : immune protection • Hemostasis : prevention of blood loss
Hematocrit:
% of total blood
volume occupied by
packed red blood
cells
Formula for hematocrit
(X/Y) X 100%
X: volume of packed red blood cells
Y: total blood volume
Anemia
Shortage of RBC and extra plasma
Polycythemia
Extra RBC and shortage of plasma
- thicker blood, more stress on heart
Plasma
Non cellular portion of the blood
ECF (outside of the cells) made of
Plasma + interstitial fluid
Composition of plasma (liquid portion of the blood)
• Mainly water (> 90%)
• Electrolytes, organic molecules, trace elements and
gases
• Substances being transported
– CO2, nutrients, waste products, hormones
Types of plasma proteins
- Albumins
- globulins (Made in lymphoid tissue)
- fibrinogen
- transferrin
Where are all the types of plasma proteins made ?
Liver
Function of albumins
Major contributors to colloid osmotic pressure of plasma; carriers for various substances
Function of globulins
Clotting factors, enzymes, antibodies, carriers of various substances
Function of fibrinogen
Forms fibrin threads essential to blood clotting
Function of transferris
Iron transport
Major functions of plasma proteins
– Distribution of body water – Buffering – Transport – Defence – Hemostasis
Serum made of ?
Serum = Plasma - clotting factors
Normal count for RBC
- 2 - 5.4 x 10^6 (F)
4. 7- 6.1 x 10^6 (M)
Wat are erythrocytes
RBC
Normal count for WBC or leukocytes
4.5 -10 x 10^3
Function of RBC
Transport oxygen
Three categories of WBC
- POLYMORPHONUCLEAR GRANULOCYTES
- MONOCYTES
- LYMPHOCYTES
Types of POLYMORPHONUCLEAR GRANULOCYTES
- neutrophils
- eosinophils
- basophils
Neutrophils
Gram uses a rented attracted to either dye, its neutral.
- highly segmented nucleus
- 40-60%
Function : phagocyte
Eosinophil
Granules are attracted to pink acidic dye
- segmented nucleus
- 1-4%
- function: defence against parasites
Basophils
Granules attracted to basic blue dye
- <1%
- function: inflammation
Monocytes
Large nucleus
- 2-8%
Function: phagocyte and immune defence
Types of lymphocytes
B-cells and T-cells
B-cells
- 20-40%
Function: antibody production , humoral immunity
T-cells
20-40%
Function: cellular immunity
Platelets function
Hemostasis
Hematopoiesis
Formation of blood cells
Where does hematopoiesis happen
– Prenatal (before birth) = yolk sac, liver, spleen
– Postnatal (after birth) = bone marrow
During hematopoiesis, what does the multipotent hematopoietic stem cells turn into
Either a
- lymphoid stem cell—-> lymphocyte (WBC)
- myeloid stem cell —>RBC or WBC or platelet
Where does the T-cells develop
In the thymus gland which is located between the lungs
Stages of blood development
- Everything starts at they bone marrow
- RBC, platelets, monocytes, granulocytes, B-cells, T-cells are then in the blood vessels
- macrophages, granulocytes, B and T cells are in tissue
Leukocyte morphology
Monocyte —> macrophage
Differentiated WBC in the tissue
How is hematopoiesis regulated?
– Cytokines
Cytokines
• are small proteins
• hormone-like in their mechanism of action
• also called hematopoietins
– act as growth factors
– e.g. erythropoietin: erythrocytes or RBCs
– thrombopoietin: thrombocytes or platelets
thrombopoietin:
thrombocytes or platelets
erythropoietin:
erythrocytes or RBCs
RBC facts
Facts – Diameter: 7-8 µm – Thickness: 2-3 µm – Number: ~5 million /µl – Lifespan: 120 days – Function: O2 transport – loses nucleus and other molecules organelles during development – bag full of Hemoglobin
Hemoglobin (Hb) structure
• = heme (non-protein) + globin (protein) • Hemoglobin A (HbA) a2B2 – Globin (4) – Heme (4) – Ferrous iron (4)
Hemoglobin and O2 transport
- Hemoglobin (Hb)
- responsible for ~98-99% of total oxygen transport
• binds to oxygen in loose
and reversible manner
• each ferrous (Fe++) iron combines with one molecule of O process of oxygenation (not oxidation)
What makes CO inhalation fatal?
• Hb can bind to other gases
– Carbon monoxide (CO) inhalation can be fatal
– Colorless and odourless gas
– Hb has 200x more affinity for CO than to O
Platelets or thrombocytes count
1.5 - 4 X 10^5
Factors essential for RBC production
- Cytokine: Erythropoietin (EPO)
- Dietary factors
- Protein factor released from stomach
Cytokine: Erythropoietin (EPO)
– Source of EPO
– Role of Testosterone
– Role of other hematopoietins
Dietary factors
– Iron
– Folic acid
– Vitamin B12
Protein factor released from stomach:
Intrinsic factor (IF)
Factors that decrease oxygenation
- Low blood volume
- Anemia
- Low hemoglobin
- Poor blood flow
- Pulmonary disease
Where do RBC go to die
Spleen and liver
Body Iron reserve:
50% : Hb
25%: other iron containing proteins 25%: bound with Ferritin
Absorption of vitamin B12
- B12 found in (liver, fish, eggs, diary) consumed
- binds to (IF) to form complex so that it isn’t broken down by stomach acid
- B12 is then absorbed into the blood through the large intestine
What does a lack of B12 cause
Pernicious anemia
What is anemia?
Decreased oxygen-carrying capacity of the blood due to a deficiency of RBCs and/or hemoglobin contained in the RBCs
What causes anemia?
- Decreased production of RBC in the bone marrow
- Increased destruction of the RBCs in the body (hemolytic anemia)
- Increased blood loss leading to loss of RBCs (hemorrhagic anemia)
- Abnormal hemoglobin production
Specific factors leading to anemia
- Lack of Iron (most common dietary cause)
- Lack of intrinsic factor or Vitamin B12
(pernicious anemia) - Damage of bone marrow due to radiation /drugs (aplastic anemia)
- Chronic kidney disease (reduced levels of
erythropoietin, EPO) - Increased breakdown due to abnormal shape of RBC or due to immune reactions during transfusion (hemolytic
anemia) - Increased blood loss due to injury, bleeding ulcers or chronic menstruation (hemorrhagic anemia)
- Abnormal structure of hemoglobin
aplastic anemia
Damage of bone marrow due to radiation /drugs
hemolytic anemia
Increased breakdown due to abnormal shape of RBC or due to immune reactions during transfusion
hemorrhagic anemia
Increased blood loss due to injury, bleeding ulcers or chronic menstruation
Abnormal Hb: Sickle cell disease
• Abnormal globin chain (sickle cell
HbS = a2b*2)
– Single amino acid mutation in the b chain
– Sickle -shaped RBCs are formed
– Cell membranes are hard and non-flexible
– Passage through capillaries cause
damage of sickled RBCs (hemolytic anemia)
– Expressed by autosomal recessive gene
carriers