Hematopoiesis - Blood Flashcards
Hematopoiesis
Formation of blood cellular components
Hematopoietic tissue
Embryo: Yolk sac; eventually liver (spleen also involved).
Adult: Bone marrow - myeloid cells and initially lymphoid cells); thymus, lymphvnodes, spleen (lymphoid cells).
Formed elements
Cells and cell fragments of blood; erythrocytes, leukocytes, platelets.
Percentage of blood taken up by RBCs
Male: 41-53%
Female: 36-46%
Percentage of blood taken up by WBCs; relative distribution amongst (pneumonic)
0.1%
Never Let Monkeys Eat Bananas
Neutrophils Lymphocytes Monocytes Eosinophils Basophils
Percentage of blood taken up by platelets
<1%
Hematocrit distribution
Plasma: 55%
Formed elements: 45%
Buffy coat (WBCs/platelets): <1%
Plasma
Liquid component of blood that normally holds blood cells.
Plasma proteins and role
Albumin: Increase osmotic pressure, carrier protein
Globulins: (Alpha, beta) Carrier proteins, fibronectin, lipoproteins, clotting factors; (gamma) immunoglobulins (antibodies)
Fibrinogen/prothrombin: Clot formation
Serum
Plasma from which fibrinogen, which causes clotting, has been removed (as well as clotting factors and contains platelet-derived growth factor).
Erythrocytes
Blood cells that function in transporting oxygen and CO2 throughout bloodstream.
Macrocyte
Enlarged erythrocyte due to low folic acid (causing decrease cellular division in progenitors)
Microcyte
Small erythrocyted due to low iron (causing increased cellular division in progenitors)
Reticulocyte
Immature RBCs normally making up 1-2% of erythrocyte population. Some ribosomal RNA can still be seen in these cells.
Concentration of erythrocytes in blood
Males: 4.5-5.9x10^6
Females: 4.0-5.2x10^6
RBC life span
120 days
RBC function
Transport oxygen to tissues and carry CO2 away
Granulocytes (names)
Neutrophils, eosinophils, basophils
Agranulocytes
Lymphocytes, monocytes
Eosinophilia
Increased number of eosinophils. Associated with allergic reactions and helminthic infections.
Eosinophil function during allergic reaction
Down regulate inflammation.
Specifically: Release histaminase and arylsulfatase granules to inactivate histamine and leukotrienes. Phagocytize antigen-antibody complexes.
Eosinophil function during helminth infection
Surround and kill parasitic worms.
Specifically: Release major basic protein, cationic protein, and peroxidase.
Distinguish between the two types of lymphocytes: B cells (include distribution, origin/maturation, location, type of immunity, functions)
Distribution: 20-30% of lymphocytes.
Origin/maturation: Originate and mature in bone marrow.
Location: Circulate via lymph and blood.
Type of immunity: Humoral (fluid) immunity.
Functions: Activate by specific antigen and a helper T cell. Precursor of plasma cells - which release antibodies).
Distinguish between the two types of lymphocytes: T cells (include distribution, origin/maturation, location, type of immunity, functions)
Distribution: 60-80% of lymphocytes.
Origin/Maturation: Originate in bone marrow, mature in thymus.
Location: Circulate among secondary lymphoid tissues.
Type of immunity: Cell mediated immuinity.
Functions: T cells activate B cells.
