Blood And Immunity Flashcards
Blood
Red blood cells = erythrocytes, ~45%
White blood cells = leukocytes, <1%
Platelets = thrombocytes, <1%
Plasma = ~55%
Blood plasma
55% of blood 90-92% water Electrocytes and glucose Clotting factors Plasma proteins (~7%) Serum = plasma without clotting factors
Clinical measures
RBC count = ~5million/mm3 WBC count = ~10,000/mm3 Hematocrit (Hct) = ratio of RBCs to total blood volume (~45%) Hemoglobin (Hb) = 12-15mg/dL Platelets = 150,000-350,000/mm3
Red blood cells
Live about 120 days 30 trillion Replace ~1% everyday Need iron Need B12 Need erythropoietin (from kidney, released if blood oxygen is too low)
Anemia
Low oxygen carrying capacity (fatigue)
Iron deficiency anemia = low iron, low hemoglobin, small cells, low Hct
Pernicious anemia = low B12, low RBC count
White blood cells
Neutrophils = phagocytes, 60-70% of WBCs Monocytes = macrophages, 2-8% of WBCs Eosinophils = allergy response, 1-4% of WBCs Basophils = histamine, <1% of WBCs Lymphocytes = T cells and B cells, 20-30% of WBCs
Blood clotting
Vascular spasm = vasoconstriction Platelet plug = sticky platelets Coagulation
Coagulation
Formation of fibrin threads
2 pathways:
Extrinsic = needs external factor
Intrinsic = slower, more fibrin
Immune system
Defence against bacteria, viruses, worms
Removes old cells
Helps with repair (injuries)
Antigen (binds with antibody)
Immunity
Non specific (innate) = quick, external defences, inflammation, interferon, natural killer cells/phagocytes, complement system Specific (acquired) = slower but stronger, T-cells (kill infected cells), B-cells (antibody response)
External defences
Skin Mucous Acid Cough Sneeze
Inflammation
Increase blood flow to injury/infection site (red/hot)
Increase permeability of capillary (WBCs and clot factors to site)
Interferon
Cytokines from infected cell
Prevents infection of other cells
Natural killer cells/phagocytes
Macrophages (cancers, bacteria)
Neutrophils (phagocytes)
Complement system
Circulating proteins
Forms attack complex (kills anything marked by an antibody)
Specific immunity
B-cells = attack free virus
Antibody reaction
T-cells = attack infected cells
B lymphocytes
Bind to antigen Divide and differentiate into: Plasma cells (secrete antibodies) Memory cells (stronger second response)
Antibody response
Antibodies bind to antigens (mark them for destruction by phagocytes and complement system)
Memory cells
Larger and longer second response
Eg) chicken pox and flu
T lymphocytes
Helper T-cells = secrete cytokines
Cytotoxic T-cells = directly attack infected cells, recognize antigen marker
Suppressor T-cells = limits response
Helper T-cells
Secretes cytokines
Mediates fever
Increases number of B and T cells
Necessary for strong response
Blood mismatch
Antibodies bind antigens (clumping, block small vessels)
Hemolytic anemia
Also Rh mismatch
Allergies
Inappropriate response to an allergen Activates mast cells Mucous secretion Inflammation response Eg) hay fever, hives, anaphylaxis
Allergic response
Inflammatory response to a non pathogenic antigen (allergen)
(Pollen/dust/animal hair/certain foods) -> (overproduction of IgE) -> (affinity for basophils and mast cells) -> (rupture of mast cell, release of histamine/serotonin/bradykinin) -> (local edema, swelling, congestion, hives)
