Blood and Hematopoesis Flashcards
what are 4 important functions of the blood system?
- gas exchange
- immunity
- tissue repair and regeneration
- tissue homeostasis
what are characteristics of plasma?
- nutrients
- waste
- signaling
- 55% of blood components
what are characteristics of RBCs?
- oxygen transport
- CO2 conversion
- 45% of blood components
what are characteristics of white blood cells?
- immunity
- clotting and repair
- signaling
- part of buffy coat
- <1% of blood components
what is a characteristic of platelets?
- hemostasis
- part of buffy coat
- <1% of blood components
what is hematopoesis?
-production of blood cells (erythrocytes and leukocytes)
where are blood cells produced?
- produced from hematopoetic stem cells in the bone marrow
- many mature in the periphery
Which 3 cells are components of the adaptive immune system?
lymphocytes:
-plasma cell, T cell, and NK cell
Which 5 cells are components of the innate immune system?
monocytes:
- macrophage
- dendritic cell
granulocytes:
- neutrophil
- eosinophil
- basophil
which 3 cells that assist in hematopoesis reside in the bone marrow?
stem cells, progenitor cells, and blast cells
what are some important characteristics of erythrocytes?
- packed with hemoglobin
- carbonic anhydrase
- CO2 exchange
- high surface area to volume ratio
- flexible
- no nucleus or organelles
what is the lifespan of a typical erythrocyte?
- 120 days
- 1-2% of total volume is replaced daily
what is hematocrit?
- erythrocyte blood count
- between 40-50%
- can be influenced by environmental factors
what hormone drives erythropoesis?
erythropoietin (EPO)
T or F: hypoxia increases lactic acid and EPO production
true
what does the production of RBCs require?
- iron
- folic acid (vitamin B9)
- cobalamin (vitamin B12)
what are the major functions of leukocytes?
- kill pathogens
- clear damaged tissues
- initiate cellular repair
- development
- organ homeostasis
what are some characteristics of neutrophils?
- primary inflammatory cell (“first responders”)
- granulocyte
- multilobed nuclei
- several effector mechanisms, including phagocytosis, degranulation, and net formation
- restricted to vasculature
- must be recruited to sites of inflammation
what are some characteristics of granulocytes?
- 3 major classes: mast cells, basophils, and eosinophils -dense granules that contain antimicrobials, NTs, pro-inflammatory signals, and growth factors
- degranulation upon activation
- predominantly reside in peripheral tissues
- respond to parasites and worms
what are some characteristics of monocytes?
- differentiate into macrophages or dendritic cells
- kill pathogens, clear debris
- phagocytose antigens
- activate the adaptive immune system (lymphocytes)
what are some characteristics of lymphocytes?
- T cells, B cells, and NK cells
- adaptive immune system
- cellular: T cells and NK cells
- humoral: B cells
- pathogens and diseased self-tissue
- immune memory (basis of immunizations)
- often require monocyte activation
what are some characteristics of megakaryocytes?
- reside within the bone marrow
- secrete platelets
what are platelets?
- small cell fragments
- organelles, but no nucleus
- involved in hemostasis
- necessary for clot formation and removal
- form plugs
- contain protein-rich granules
- involved in the inflammatory response
- structural-protein dense
what is hemostasis, and what are the three mechanisms that drive it?
prevention of blood loss
1) vascular constriction
2) platelet plug
3) coagulation - fibrin matrix formation and fibroblast recruitment
draw the coagulation pathway
what two pathways produce prothrombin activator?
1) intrinsic pathway - begins in the blood
2) extrinsic pathway - begins at the site of tissue trauma
*these pathways function simultaneously
what do the intrinsic and extrinsic pathways produce, and what are some simiilarities of these pathways?
- leads to the production of prothrombin activator
- most factors in pathway are proteases
- vitamin K is essential
- fibrinolysis degrades the fibrin meshwork
