Components of the hematologic systems:
Blood
Lymphoid organs
Mononuclear phagocyte system
2 fluid connective tissues
1) Blood
2) Lymph
pH of blood
7.4
Temperature of blood
34 Celsius
Blood makes up of how much % of body weight
8% or about 5L in average-sized human
Male: 5-6L
Female: 4-5L
Blood serve 3 main functions:
1) Transportation
2) Regulatory
3) Protection
Transportation includes:
Deliver Oxygen and nutrients to cell
Remove CO2 and waste
Hormone to organs
Regulatory include:
Temperature
pH
Water content in cells
Protection includes:
Prevent blood loss via clot formation
Prevent infection via iflammation and immune responses (antibodies, WBC, proteins)
2 major components of whole blood:
1) Formed elements
2) Plasma
Formed elements make up ?%
45% of the whole blood
Hematocrit (Hct) is:
The term for the % of blood (by volume) that consists of RBCs
Average Hct:
Male: 47 ( range: 40-54)
Female: 42 (Range: 37-47)
3 major types of formed elements:
1) Erythrocytes or RBCs (transport function)
4-6 million/ cubic millimeter of blood
2) Leukocytes or WBCs
- Body defense is the major function
- 4,400 to 11,000/ cubic millimeter of blood (uL)
3) Platelet or Thrombocytes
- Clotting function
- 150,000 to 4
Plasma makes up ?% of volume of blood
55% of the whole blood volume
(it is 90% water)
Color of plasma
Straw-colored sticky fluid whose composition varies as cells add and remove substances
Beside water, 10% of plasma includes:
1) Protein
2) Metabolic wastes (nonprotein nitrogenous substances)
3) Nutrients (glucose, AA, fatty acids, vitamins)
4) Electrolytes (Na, K, Ca, Cl, HPO4, HCO3, Mg, SO)
5) Respiratory gases (O2, CO2)
Proteins in plasma includes:
1) Albumin 60%
2) Globulins: 35% of plasma
3) Clotting proteins: 4% (fibrinogen)
Albumin is:
60% of plasma. produced by the liver. It exerts osmotic pressure to hold water in the CV system
Globulins is
35% of plasma protein.
Alpha: produced by liver, serve as transport proteins for bilirubin, lipids, and steroids.
Beta: produced by liver, serve as transport proteins for iron and copper.
Gamma: produced by plasma cells during immune response. Serve as an
RBC or Erythrocytes function:
1) Transport O2 and CO2
2) Buffer H+ (globin)
RBC structure complementing fuction:
1) Biconcave disc shape: greater surface, greater gas exchange. Very flexible (fold up when travel through capillaries that's smaller than RBC - 7.5 um)
2) Lack nuclei and no organelles: 97% hemoglobin to trasport oxygen. 100 times more oxygen then dissol
Structure of Hemoglobin:
Globin (4 polypeptide chains) bound to ringlike Heme pigment (each heme has an atom of iron bound to its center)
One Hemoglobin can bing to ? molecules of oxygen
4 since each iron can combine with one molecule. And there are 4 chains => 4 irons
1 single RBC can carry how much?:
250 million of Hb => 1 billion molecules of Oxygen
Average concentration of hemoglobin in the blood is
15g/ 100mL blood
Oxygen binds to iron of Hb, Hb becomes
Birght red and is called OxyHb
Oxygen detaches from Hb at the tissues, Hb becomes
Dark red and is called DeoxyHb or reduced Hb
% of body's oxygen is carried bound to Hb
97%
% of CO2 bound to Hb
20%
Rather than being bound to the heme group, CO2 is bound to
The Amino Acids of the globin protein
=> CarbaminoHb
CO bound to amino acids is called
CarboxyHb
When fully saturated, 1g Hb can carry
1.34 mL Oxygen
Calculation for total Oxygen carried on Hb/dL blood:
%Saturdation x 1.34
Leukocytes (WBC) are:
Complete cells (have nuclie and usual organelles)
Major functions of WBCs:
Defend against disease
Remove dead or injured host cells.
Ways for WBCs to exit the bloodstream and enter tissue beds:
1) Chemotaxis: move toward chemical substances released by microbes and inflamed tissues
2) Emigration (or diapedesis): process by which WBCs leave the bloodstream (WBCs squeeze through the capillary endothelial cells and move through tissue spaces by amo
2 major categories of WBCs:
1) Granulocytes (neutrophils, eosinophils, basophils)
2) Agranulocytes (monocytes and lymphocytes)
Neutrophils:
Most numerous of WBCs
3-6 lobes => Polymorphonuclear leukocytes
Phagocytize bacteria
Eosinophils:
Large granules that stain red with acidic stains
2 lobes
Function of Eosinophils:
1) Decreases severity of allergies by decreasing the inflammatory response
2) Phagocytize soluble Ag-AB complexes
3) Fight parasitic worms
Basophils:
Large granules dark stain (deep blue with little dots)
Lobed nucleus
Basophils release:
1) Heparin: anticoagulant
2) Histamine: Inflammatory chemical acts as a vasodilator
Monocytes:
Largest of the leukocytes (distinctive U shaped or kidney-shaped)
Differentiate to Macrophages
Lymphocytes:
2nd most numerous WBC
Smallest WBC
Large dark nucleus occupies most of the cell volume
3 types of Lymphocytes:
1) T-cells (adaptive)
2) B cells (adaptive)
3) Natural Killer Cells (innate)
Platelets are also called
Thrombocytes
- Fragments of very large cells called megakaryocytes
Life span" 4-5 days
Hormone that stimulates platelet formation is called
Thrombopoeitin
Platelet function is:
1) Form a platelet plug
2) Platelets have granules that contain necessary clotting factors which are released upon degranulation
Primary Vs Secondary Lymphoid organs:
Primary: Thymus and Bone
Secondary: Spleen, Lymph nodes, tonsils, peyer patches of the small intestine
Spleen (largest) functions:
1) Serve as site of fetal hematopoeisis
2) Filter and cleansing blood
3) Reservoir for lymphocytes and other blood cells
4) Mointing an immune response via lymphocytes within the white pulp
Lymph nodes:
Site of development or activity of lymphocytes, monocytes and macrophages
MPS
Mononuclear phagocyte system
- Main line of defense against bacteria in the bloodstrean
- Cleanses the blood by removing old, injured, or dead blood cells; antigen-antibody complexes; and macromoplecules
Hematopoiesis
Blood cell production in liver and spleen of fetus, bone in after birth
Hematopoietic stem cell give rise to:
1) Common lymphoid progenitor (B, T and NKC)
2) Myeloid stem cell (Monocyte, Neutrophil, Eosinophil, Basophil, Mat cell, megakaryocyte, erythrocyte)
RBC production is called:
Erythropoiesis
Erythropoiesis has 3 stages:
1) An immature RBC produces large numbers of ribosomes
2) Hb is synthesized and accumulate in the cytoplasm
3) RBC ejects its nucleus and most of its organelles (inward, biconcave) => Become Reticulocyte (enters blood stream) => Mature into RBC within 2 d
EPO
Erythropoietin secreted by kidneys in response to tissue hypoxia.
Cause increases in RBC production when oxygen is low
Negative feedback:
Decreases blood Oxygen => Kidney => Release EPO => Stimulate bone to increase RBC production => Increase Blood Oxygen
Causes of decreased blood oxygen:
1) Anemia
2) High altitude
3) Pulmonary disease
Dietary substances important for RBC production:
1) Iron
2) Vitamin B12 (so intrinsic factor can be absorbed)
3) Folic acid
Hemostasis stages:
1) Vascular spasm (vasonconstriction)
2) Platelet plug formation (release: ADP, Thromboxan A2, Serotonin, Ca++ released, Platelet factors)
3) Coagulation:
- Prothrombin activator is formed
- Prothrombin activator convertss prothrombin to thrombine
- Throm
Fibrinolysis:
Once healing occurred, the clot becomes unnessary and fibrinolysis occes.
Factors prevent undesirable clot:
1) Properties of normal vascular endothelium (smooth texture, no basement membrane)
2) Antithrombin
3) Heparin
4) Prostacyclin (prostaglandin derivative by endothelial cells)
Anticoagulants:
1) Antagonize Vitamin K (wafarin)
2) Remove Ca++ from the plasma (sodium citrate)
3) Block synthesis of or activation of various clotting factors (aspirin blocks Thromboxane A2)