hematology Flashcards
fxn of blood
- transport nutrients
- regulates pH
- warms and cools the body
plasma
- extracellular matrix
define hematopoiesis
- production of blood cells
- stimulated by erythropoietin
- controlled by cytokines
what is the most common to least common WBCs
- neutrophils
- lymphocytes
- monocytes
- eosinophils
- basophils
bone marrow
- where blood cells are produced
- red bone marrow: red bc it contains hemoglobin; active
- 25% RBCS, 75% WBCs
- yellow bone marrow contains adipose cells; inactive
red blood cells
- erthyrocytes
- like hemoglobin
platelets
- split off from megakaryocytes
- patch up any wound
- life span of 10 day life
- imp for stopping blood loss, immunity, and inflammation
white blood cells
- leukocytes
albumin
- most common protein in the blood
transferrin
- transports iron
fluid matrix of blood
- Water
- Proteins
- Remaining 1%
- Ions (Na, K, Cl, H, Ca, HCO3)
- Organic molecules
- Gases (O2 and CO2)
- Trace elements
- Vitamins
colony stimulating factors
- regulate leukopoiesis
- CSFs
- leukopoiesis: production of WBCs
thrombopoietin
- regulates platelet production
- TPO
- kidneys secrete this
erythropoietin
- regulates red blood cell production
- EPO
- responds to low blood volume secreted by kidneys
- erythropoiesis: production of RBCs
hematocrit
- when we’re looking @ RBC
- the percentage of total blood volume that is occupied by packed (centrifuged) red blood cells.
- ratio of RBCs to plasma, expressed by a %
mean corpuscular volume (MCV)
- size of RBCs
hemoglobin plays a role in what?
- oxygen transport
four globulin molecules
- four heme groups
- several isoforms
Heme is a porphyrin ring with an iron (Fe) atom at its center
– Iron comes from diet
– Transported in blood by transferrin
– Iron taken up in bone marrow
– Excess iron stored in liver by ferritin
how long do RBCs live for?
- 120 days or 4 months
where do older RBCs go?
– Older RBCs rupture or phagocytized in spleen
amino acids from globin are incorporated into what?
- new proteins
true or false. some iron from heme groups are reused in new heme groups
true
remnants of heme groups are converted to bilirubin, excreted as bile
– Bilirubin metabolites are excreted in urine
– Jaundice results from elevated levels of bilirubin
how iron and hemoglobin go thru the blood
- iron ingested from the diet
- Fe absorbed by active transport
- transferrin protein transports Fe in plasma
- Bone marrow uses Fe to make hemoglobin as part of RBC synthesis
- RBCs live about 120 days in the blood
- spleen destroys old RBCs and converts hgb to bilirubin
- bilirubin and metabolites are excreted in urine and feces
- liver metabolizes bilirubin and excretes it in bile
- liver stores excess Fe as ferritin
biconcave disks
- Mature mammalian red blood cells in an isotonic solution are biconcave disks, shaped much like jelly doughnuts with the filling squeezed out of the middle
megakaryocyte
- Red blood cells have lost their nuclei by the time they enter the bloodstream, and platelets, which also lack a nucleus, are cell fragments that have split off a relatively large parent cell
hemostasis
- prevents blood loss from damaged vessels
hemostasis and coagulation
– Vasoconstriction
– Platelet plug begins with platelet adhesion
– Exposed collagen and tissue factor lead to a clot
▪ Coagulation (bringing platelets tgthr to cover up the hole) cascade
– Thrombus
platelet activation begins the clotting process
– Platelets stick to collagen in damaged vessels
– Release of platelet-activating factor (PAF) –> thromboxane A2
– Prostacyclin: blocks platelet adhesion and aggregation
coagulation has two pathways
– Intrinsic pathway known as contact activation pathway
– Extrinsic pathway known as cell injury pathway
fibrinolysis
- Plasmin then breaks down fibrin, a process known as fibrinolysis
plasmin
- As the damaged vessel wall slowly repairs itself, the clot disintegrates when fibrin is broken into fragments by the enzyme plasmin
fibrin
- part of the clot
- laying down of scar tissue
coagulation
- the process by which blood clots prevent blood loss in damaged vessels.
thrombus
- a blood clot that adheres to an undamaged blood vessel wall
adaptive immunity
– Specific immune response
– Slow (days to weeks)
– “Remembered” by immune system
– Cell-mediated immunity (like injecting botox) (phagocytosis)
▪ Contact-dependent signaling
– Antibody-mediated (humoral) immunity
▪ Antibodies (more viruses have these)
innate immunity
- anything and everything gets exposed to this
– Immediate immune response
– Non-specific
– Rapid (minutes to hours)
– Inflammation is characteristic
– Antigen-presenting cells (APCs)
– “Not remembered” by immune system
macrocylic anemia
- B12 def
- RBC = big
microcyclic anemia
- iron def
- RBC = small
what carries out internal response for immune system?
- leukocytes
- communicate via cytokines
t lymphocytes (T cells)
- migrate from bone to thymus to mature
- t cell receptors: look and say is this us or someone else
b lymphocytes (B cells)
- mature in bone marrow
– Activated B cells differentiate into plasma cells and secrete antibodies (also called immunoglobulins)
IgG
– most abundant in serum, produced in secondary responses, crosses the placenta, reacts with complements
IgA
– in external secretions
IgE
– target gut parasites and are associated with allergic
responses
IgM
– associated with primary responses, react strongly with complements
IgD
– appear on the surface of B cells, role unclear
antibodies
- proteins secreted by immune cells, to carry out the immune response.
- bind to foreign substances to disable them or make them more visible to the cells of the immune system
antigens
- Immunogens that react with products of the immune response are known as antigens
- any substance that causes your immune system to produce antibodies against it
natural killer (NK) cells
- form a third category of lymphocytes
- They are thought to develop in bone marrow as well as in other tissues
- kill anything and everything
- can also kill our own cells
plasma cells
- lymphocytes and their derivative plasma cells are the key cells that mediate the specific adaptive immune response of the body
T lymphocytes – CD4 and CD8
- CD4: MHII (HIV)
- CD8: MHI
universal donor and acceptor
- donor: O-
- accept: AB+
