Hematology Flashcards
General Features of Blood
- Type of connective tissue
- Transport: oxygen and other nutrients, waste products, hormones, heat and cells
- Clinical tests: Hematocrit and differential count
Formed Elements of Blood
- Cellular Material
- Red blood cells (erythrocytes)
- White blood cells (Leukocytes)
- Platelets( from megakaryocytes)
Differential Count
- Used to see the composition of cells in persons blood
- The blood is smeared and dried
- Then stained with Romanovsky type stain
Granulocytes`
- Neutrophils
- Eosinophils
- Basophils
Agranulocytes
- Lymphocytes
- Monocytes
Plasma
- 90% water, 10% solutes
- Solutes contain: proteins, small organics, and inorganics
Plasma proteins
- Albumin (60%)- Contribute to osmotic pressure and can act as a lose binding protein
- Globulins (35%)- include antibodies and transport globulins
- Fibrinogen (4%) function in forming blood clots
Small organics in plasma
- lipids
- carbohydrates
- amino acids
- organic wastes
Inorganic solutes in plasma
- electrolytes (Na+, K+, Ca+, etc..)
Erythrocytes
- Red blood cells
- No nucleus
- Cannot repair damaged proteins in the cell
- limited life span (120 days)
- very flexible, needs to squeeze through capillaries
Glycophorin
- one of two major transmembrane proteins exposed to the outer surface of the red blood cell
Anion Tranporter Channel
- Allows bicarbonate to cross the plasma membrane in exchange for chlorine
- facilitates the release of CO2 in the lungs
Function of Erythrocytes
- Gas exchange (oxygen and CO2) is number one function
- sickle cell anemia is caused by point mutation in hemoglobin
- creates a more sickle cell shape
- makes it inflexible and it is removed by spleen
Anemia
Low concentration of hemoglobin in the circulatory system
Causes:
- Loss of blood- hemorrhage
- insufficient production of RBCs (low erythropoietin from kidney)
- RBCs with insufficient hemoglobin (iron deficiency)
- Accelerated RBC destruction
RBC Life Cycle
- Made in bone marrow and released after about a week in the circulatory system
- Last about 120 days
- removed once they become inflexible
- Most of the time this happens in the spleen but 10% of the time it happens in the blood vessels
Neutrophils
- Most common nucleated cell in the blood
- sometimes called polymorphonuclear leukocytes
- as it ages it becomes more lobulated
- sometimes you will see a drumstick appendage- Barr Body- inactive X chromosome in female
Non specific Granules in Neutrophils
- primary lysosomes
- myleoperoxidase and acid hydrolases
Specific Granules in Neutrophils
- Salmon pink
- secondary, or neutrophilic
- Proteases and lysoszyme
Diapedesis
- the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation.
Neutrophils Chemotaxis
- Movement of neutrophils by the process of chemotaxis toward an area of tissue damage
- Move towards chemical signals, toxins
Oxygen Dependent Phagocytosis of Bacteria via Neutrophils
- Oxygen is converted into super oxide radical
- then converted to hydrogen peroxide
- then converted to hypochlorous acid (bleach)
Oxygen Independent Phagocytosis of Bacteria via Neutrophils
- Lysosomal degradation
How Neutrophils possibly cause cancer
- Neutrophils attacking bacteria and bleach type compounds are being released
- Inadvertently release reactive oxygen species which can damage normal cell’s DNA
- When normal cells repair their DNA, you can get a mismatch pair and this damages the nucleotides
- A single mutation probably wont do anything but after an accumulation of these mutations, you can have very damaged DNA and it can cause cancer
Eosinophils
- contain lobulated eosinophilic granules
- Eosinophilc Granule has two parts (striped)
1) Externum - Peroxidase, Hydrolyic enzymes
2) Internum (crystalline) - Major basic protein, eosinophil cationic protein, Neurotoxin - Attack parasites
- Limits Inflammation (by inactivating Leukotrienes and histamine)
- 2-4% of leukocytes
Eosinophil Chemotaxis
- migrate by diapedesis and chemotaxis in response to eosinophilic chemotactic factor secreted by basophils
Basophils
Have large Basophilic granules that contain: - Heparin (anti-coagulant) - Proteases - Histamine (increases vasuclar permeability, Vasodilator - Eosinophil chemotactic factor Functions: - Inflammation - Recruit eosinophils About 0.5% of leukocytes
Inflammatory Activity of Basophils and Mast Cells
- Specific antigen bridges two adjacent IgE receptor molecules anchored to membrane receptor
- Cytosolic calcium is mobilized
- Granule and lipid mediators and cytokines are released
Monocytes
- Monocuclear phagocyte system- group of cells that play a role in phagocytosis
- Differentiate into Macrophages and other phagocytic cells
- Functions:
1) non specific phagocytosis
2) antigen presenting - 5% of leukocytes
Antigen Presenting of Macrophages
- Antigen is phagocytized, and the macrophage will use a lysosome to degrade it
- Small peptides will be formed and bind with MHC
- Then the MHC will be used to present the antigen to T cells
- The T cell will then produce antibodies to destory the rest of the antigens in circulation
Platelets
- Fragments of cells released from bone marrow
- Contains Hyalomere and Granulomere
- Contains Platelet derived growth factor- used for endothelial cell mitosis
Hyalomere
- Peripheral microtubules and microfilaments in platelets
Granulomere
- The central portion of the platelet
- Contains granules and lysosomes
Hemostasis
- Vascular injury
- Vasoconstriction - Reduces blood loss
- Platelets adhere to collagen fibers in extracellular space
- Aggregate- act as a plug
- Release of fibrinogen which promotes blood clotting cascade
- Becomes fibrin which acts as a net