All about Hematology
What is a hematocrit?
% packed cell volume
- add an anticoagulant, centrifuge
- Heavy elements move to bottom, lighter ones stay on top
What is the function of Erythrocytes?
Transport O2, transport CO2, buffer pH
What are the 5 types of leukocytes?
Neutrophil, eosinophil, basophil
Monocytes, lymphocytes
What are monocytes good for? what percent do they make up?
2-6% of WBC
Respond to chemotaxis and perform diapedesis
transformed into macrophages once in the tissue
macrophages can also acts as sensors in acquired immunity by becoming APC
generate free radicals
Thrombocytes in mammals vs non mammals differences are?
Thrombocytes in all vertebrates except mammals
Mammals = megakaryocytes shed platelets, platelets circulate for 2 weeks then get removed, and production is controlled by thrombopoietin
Non mammals = thrombocytes circulate as inactive cells, activated by an injury nearby, start breaking up into platelets-like fragments
Between lymphocytes and neutrophils, which animals have a higher number of each?
Lymphocytes > neutrophils in cattle, sheep, goat, pig
Neutrophils > lymphocytes in humans and dogs
How does hemoglobin get into the s-shape
Each of the 4 globin subunits can change shape - R state (relaxed and high affinity for O2), T state (tense and low affinity for O2)
Each time one subunit changes shape, it becomes easier for the others to change to - postage stamp hypothesis
What are neutrophils good for? What percent do they make up?
60-70% of WBC
highly mobile phagocytic cells that engulf and destroy unwanted materials, such as bacteria
Target anything carrying a non-self antigen
Neutrophil counts go up with bacterial infections
perform diapedesis
What are lymphocytes good for? What percent do they make up?
25-33% of WBC
B/T lymphocytes are primary cells of acquired immunity
b-lymphocytes = secretes antibodies, leading to the destruction of foreign material
T-lymphocytes = involved in cell mediated immunity, for cells invaded by virus or cancer via non self anitgen regognition
NK cells = kills any cell that doesn't have the correct surface protein MHC, form innate immunity
Platelets anticlotting regulations?
Important to prevent inappropriate clotting?
Low concentration of circulating fibrin in the blood, no clot because plasmin activated by tissue plasminogen activator in the tissues (especially the lungs)
4 major lipoproteins?
Chylomicrons, high-density LP, low-density LP, very-low-density LP
What changes shift the dissociation curve to the left? right?
pH dropping = right shift - therefore pH rising = left shift
Temp increasing = right shift - therefore temp lowering = left shift
Organic phosphate inside the red blood cell = right shift
Carbon monoxide = left shift
What are the 4 steps of Diapedesis
Chemoattraction - when pathogens are recognized, macrophages release cytokines and chemokines
Rolling adhesion - leukocytes binds to selectin and roll
Tight adhesion - chemokines activated the rolling leukocytes and make it bind with integrin from the endothelium surface
Transmigration - leukocytes flatten and extend pseudopodia
How does innate immunity work?
Innate response to invasion and tissue injury = stop the spread of damage, brings fluids, phagocytes, defensive proteins to the injured site
Sequence of events = defense by resident tissue macrophages, mast cells become activated to release histamines, cytokines + histamines cause local capillary vasodilation and permeability, recruitment of circulating leukocytes by chemotaxis, destruction of bacteria, tissue repair, mediation of inflammation and fever
What is active vs. passive immunity?
Active immunity is self generated
passive immunity when IgG and IgA are obtained externally
What is Hemostasis? what are the steps?
The process of stopping bleeding
Vascular spasm, Formation of the platelet plug, Blood coagulation
How are erythrocytes regulated?
Spleen is responsible for it - removes the old, fragile cells to be eaten by macrophages
and is a reservoir for RBC - stores the healthy RBC + platelets + lymphocytes
What are eosinophils good for? what percent do they make up?
1-4% of WBC
respond to chemotaxis and perform diapedesis, recruiting to site of parasitic and some bacterial infections
Released extracellular chemicals to destroy the target
Involved in allergies
Eosinophil count will go up with parasitic infections
How does acquired immunity work?
B and T cells have receptors that act as sensors that only binds to one specific antigen
It is long term immunity
B cells have two functions - bind to antigen and hinder their progress, and amplify the innate immune response
T cells have 3 types - Cytotoxic, Helper, and Regulatory
Differences between Mast cells and Dendritic cells are?
Mast cells = type of granulocyte, present in barrier tissues, release of histamine and heparin, role in allergies and anaphylaxis
Dendritic cells = present in barrier tissues and many others, key sensor in acquired immunity but also has innate recognition abilities, can become antigen-presenting cells
What are the three types of Plasma proteins? and their specific functions?
Albumins (55%) - transport hormones & trace elements & free fatty acids & drugs, buffer + onconic pressure
Globulins (38%) - transporters of a, b globulins, clotting agents, regulators of inactive proteins waiting to be activated, immune effectors
Fibrinogen (7%) - key factor in blood clotting process
How does the death of hemoglobin happen?
Globin -> broken down into amino acids and recycled
heme = iron is taken back to liver & bone marrow for new RBC, Rest of pigment broken down into - biliverdin (green-ish), bilirubin (yellow) gets transferred to liver, bilirubin then transferred to SI via bile and kidneys, and then is excreted
What are basophils good for? what percent do they make up?
<1% of WBC
Release histamines
Release heparin
Release proteolytic enzymes
involved in allergies
have IgE receptors
Plays a role in inflammation
Phagocytic = macrophages release toll-like receptors that tag bacteria, TLR + antibodies help identifying the cells to destroy
Nonphagocytic = release chemicals toxic to microbes, release of lactoferrin that binds with iron-> unavailable for bacteria, release IL1 and IL6 to lower iron
What is the differences between neutrophil/eosinophil/basophil vs monocyte/lymphocytes?
M&L = mononuclear agranulocytes - mononuclear is a one lobe nucleus, agranulocytes are the absence of granules in their cytoplasm
N&E&B = polymorphonuclear granulocytes - polymorphonuclear is a nucleus of various shapes usually with 3 lobes, granulocytes are the presence of granules in their cytoplasm.