Blood (B1-B3) Flashcards
what are the two major components of plasma
water & solids (proteins, glucose, etc)
the chemical composition of plasma is very similar to this fluid in most tissues
interstitial fluid
these are the two extracellular fluids, one is intravascular and the other in extravascular
plasma and interstitial fluid
this is the process by which formation and development of all blood cells takes place
hematopoiesis
where does hematopoiesis take place in adult mammals
marrow of flat bones and ends of long bones
where does hematopoiesis take place in neonate and juvenile mammals
bone marrow of long bones
what 3 essential physiologic components are required for hematopoiesis
- stem cell pool
- hematopoietic inductive microenvironment
- hematopoietic cytokines
these are the hormones that regulate hematopoiesis
hematopoietic cytokines
the first step in hematopoietic differentiation involves a commitment of the stem cell to one of these two large pathways
myeloid or lymphoid
what is the earliest recognizable erythroid precursor
rubriblast
during the mitosis divisions of rubriblast to late precursors metarubricytes, what 3 things change on the progressive maturation of the nucleus and cytoplasm
- decreasing cell size
- increasing proportion of the cell occupied by cytoplasm (N:C ratio decreases)
- decreased cytoplasmic basophilia (decr in organelles, incr in hemoglobin content)
this is an immature, but non-nucleated RBC; larger than a mature RBC (higher MCV) and contain less Hb (low MCHC)
reticulocyte
this is the principle hormone regulating erythropoiesis; stimulates the increase of RBCs therefore increasing the oxygen-carrying capacity of the blood
Erythropoietin (EPO)
where is Erythropoietin (EPO) produced?
kidney (by the peritubular interstitial cells)
what are 4 major functions of Erythropoietin (EPO)
- proliferation of committed erythroid cells
- increases hemoglobin synthesis
- increases erythroid cell maturation rate
- stimulates early release of reticulocytes
what are the 3 major function of mature erythrocytes (RBCs)
- transport oxygen to tissues
- transport CO2 to lungs
- buffer hydrogen ions
how are the energy needs of RBCs met?
anaerobic glycolysis (no mitochondria)
what is the principle energy source for RBCs
glucose
the anaerobic glycolytic pathway produces a net gain of these 2 things
ATP & NADH
what is ATP used for in RBCs
to maintain osmotic stability
what is NADH used for in RBCs
in the process to keep iron molecules in a reduced state
this is a side pathway associated to anaerobic glycolysis which generates other products for erythrocyte metabolism:
produces 2,3-DPG which modulates affinity of hemoglobin for O2
DPG shunt
this is a side pathway associated to anaerobic glycolysis which generates other products for erythrocyte metabolism:
generates NADH, involved in maintenance of Fe and GSH in reduced states; GSH involved in protecting from oxidative injury
pentose phosphate pathway
the rate of iron absorption is influenced by the need for Fe in the body, and is controlled by this peptide secreted by hepatocytes
hepcidin
in plasma, nearly all Fe is bound to this
transferrin
this is a large tetramer protein formed by 2 alpha and two beta global chains, each linked to a heme molecule
hemoglobin
each Hb molecule has the capacity to carry this many oxygen molecules
4
why is the binding of the first oxygen molecule to hemoglobin difficult but then easier for the 2nd, 3rd, and 4th
conformational change in Hb structure with oxygenation
Hb (Fe3+) is referred to as this, which is non-functional as it is incapable of binding oxygen
methaemoglobin
what 2 things are needed in order to reduce methaemoglobin back to functional hemoglobin and prevent accumulation
methemoglobin reductase (Cb5R) and NADH
what are the three possible forms of oxidative injury to red cells
- oxidation of iron to cause methaemoglobinaemia
- oxidative denaturation of Hb to form Heinz bodies
- oxidative injury to membrane proteins
this is a reversible oxidative injury to RBCs, there is a brown discoloration of the blood and clinical signs of hypoxia
oxidation of iron to cause methaemoglobinaemia
this is an irreversible oxidative injury to RBCs, it is due to denaturation of the global part of Hb and is seen as small round projections from the surface of the RBC in blood smears
oxidative denaturation of Hb to form Heinz bodies
this is the rarest form of irreversible oxidative injury to RBCs, it is the most subtle and difficult to detect morphologically
oxidative injury to membrane proteins
this species have unique Hb structure which increases their sensitivity to oxidative injury; very susceptible to Hb oxidative denaturation and readily develop Heinz bodies
cats
what is the approximate erythrocyte lifespan in horse/cattle
150 days
what is the approximate erythrocyte lifespan in dogs
100 days
what is the approximate erythrocyte lifespan in cats
70 days
Heme breakdown leads to the formation of these 3 things
- bilirubin
- CO
- iron
unconjugated bilirubin (uBil) is transported in the blood, associated with albumin, to these cells where it is conjugated
hepatocytes
uBil is conjugated with this to form conjugated bilirubin (cBil)
glucuronide
conjugated bilirubin (cBil) is transported to the intestines with bile where it is degraded to this
urobilinogen
urobilinogen can either be absorbed by the intestine and excreted in urine or through bile - or it can be degraded to this and excreted in feces
stercobilinogen
this is the easiest and cheapest way to evaluate erythrocytes in blood; obtained by microcapillary tube centrifugation to measure the percentage of blood composed of RBCs
packed cell volume (PCV)
this is often used interchangeably with PCV (packed cell volume) and is quite similar but is calculated by automated analyzers based upon average RBC size and number
hematocrit (Htc)
as a rule of thumb, hemoglobin in mammals should e roughly this fraction of the hematocrit (Hct)
1/3
a decrease in PCV, RBC, and Hb is termed this and could be due to RBC loss or lysis, or to decreased bone marrow production of RBCs
anaemia
an increase in PCV, RBC, and Hb is termed this and is most frequently due to dehydration
erythrocytosis
this is the average volume of erythrocytes
mean corpuscular volume (MCV)
this means that the size of erythrocytes (the mean corpuscular volume-MCV) is within reference interval for the species
normocytic
this means the size of erythrocytes is increased, so MCV is low
macrocytic
this means the size of erythrocytes is decreased, so MCV is high
microcytic
this means the size of erythrocytes is decreased, so MCV is low
microcytic
this is the average concentration of RBC Hb on a weight per volume basis
mean corpuscular hemoglobin concentration (MCHC)
this means the cell Hb content (color), or MCHC value, is within the reference interval for the species
normochromic
this means the cell Hb (color) is decreases, so MCHC is low - reticulocytes have a slightly lower Hb content
MCHC
what are the two main categories of leukocytes
granulocytes and mononuclear cells
these are leukocytes with granules in their cytoplasm, the granules have different staining characteristics allowing them to be distinguished
granulocytes
what is the other name used for granulocytes bc they have lobulated nucleus
polymorphonuclear cells
what are the 3 types of granulocytes
neutrophils, eosinophils, basophils
what are the two types of mononuclear cells
lymphocytes and monocytes
what are the two most common leukocytes
neutrophils and lymphocytes
where does the majority of leukopoiesis for granulocytes and monocytes occur
bone marrow
where does the majority of leukopoiesis for lymphocytes occur
extra medullary sites (spleen, lymph nodes, GALT)
what are leukocyte precursors (and all hematopoietic cells) derived from
stem cells
what 3 major marrow pools are neutrophil precursors present in
- mitotic pool
- maturation pool
- storage pool
what is the mitotic pool in relation to where neutrophil precursors are present in the bone marrow
where cells divide while maturing
what is the maturation pool in relation to where neutrophil precursors are present in the bone marrow
where cells continue maturation but have lost ability to multiply
what is the storage pool in relation to where neutrophil precursors are present in the bone marrow
where mature neutrophils are stored
this gives the total number of leukocytes
total white blood cell count
what is it called if there is an increase in total WBCs
leukocytosis
what is is called if there is a decrease in total WBCs
leukopenia
this represents the differentiation of leukocytes in the 5 categories (neutrophils, eosinophils, basophils, lymphocytes, and monocytes)
differential count
what are the 3 aspects that must be involved when evaluating the leukocytes in blood?
- total white blood cell count
- differential count
- morphology
when in the blood vessels, what are the two main pools neutrophils are present in
marginal pool and circulating pool
these leukocytes’ nuclei have condensed dark purple chromatin that is segmented into lobes connected by filaments; cytoplasm is generally colorless and granules do not stain
neutrophils
this is an immature neutrophil with a curved (C or S-shaped) nucleus
band neutrophil
what does a “left shift” refer to in terms of circulating neutrophils
increase in circulating band neutrophils
what is the presence of left shift (increase in circulating band neutrophils) indicative of?
inflammation or infection in the body
what 4 things can represent toxic changes (morphological abnormalities of the cytoplasm) of neutrophils
- increased cytoplasmic basophilia
- Döhle bodies
- foamy cytoplasm
- toxic granules
what are Döhle bodies (toxic change in neutrophil cytoplasm)
aggregates of rough ER
what is an increase in the absolute numbers of neutrophils called
neutrophilia
what are 3 common causes of neutrophilia
- catecholamine-mediated stress
- corticosteroid-induced
- inflammation
what is a decrease in the absolute numbers of neutrophils called
neutropenia
what are 4 common causes of neutropenia
- acute severe inflammation
- endotoxemia
- reduced neutrophil production in the marrow
- increased peripheral destruction
acute severe inflammation can lead to this, which is characterized by presence of an absolute number of immature neutrophils that exceeds the absolute number of segmented neutrophils
degenerative left shift
these reproduced by some gram-negative bacteria and can cause a rapid shift of neutrophils from the circulating to the marginal pool in blood vessels by promoting adhesion to endothelial cells, leading to neutropenia
endotoxins
these are sophisticated immune cells involved in both cellular and humoral immunity, arise from pluripotent stem cells that diverge at an early stage
lymphocytes
where does lymphopoiesis mainly take place
peripheral lymphoid tissue
what are the 3 types of lymphocytes
T lymphocytes, B lymphocytes, NK (natural killer) cells
these leukocytes are small round cells with a round nucleus, dense chromatin, and a scant rim of clear to pale blue cytoplasm
lymphocytes
these lymphocytes are larger with deeply basophilic (blue) cytoplasm and course (mature) chromatin patter; nuclei can appear convoluted; associated with immune response and are fairly common in young animals
reactive lymphocytes
an increase in the absolute numbers of lymphocytes is called this
lymphocytosis
name 5 causes of lymphocytosis
- catecholamine-mediated stress
- young animals
- chronic inflammation
- endocrine disorders
- lymphoid neoplasia
a decrease in the absolute numbers of lymphocytes is called this
lymphopenia
name 3 causes of lymphopenia
- corticosteroid-induced
- acute inflammation
- excess loss
monocytes are produced here
bone marrow
monocytes migrate to tissues where they differentiate into these two cells
macrophages and dendritic cells
what are the 3 major functions of monocytes (& macrophages/dendritic cells)
- phagocytosis
- antigen presentation
- immunomodulation
these leukocytes have variably-shaped nuclei (rounded, bean-shaped, band-shaped or convoluted), chromatin is less dense compared to neutrophils, and moderate amount of blue-grey cytoplasm frequently containing variably-sized vacuoles
monocytes
an increase in the absolute numbers of monocytes is called this
monocytosis
what are 2 causes of monocytosis
- inflammation
- corticosteroid-mediated
these leukocytes are primarily involved in the defense against parasites, and in allergic reactions
eosinophils
these leukocytes have a segmented nucleus and orange/pink granules in the cytoplasm
eosinophils
this is the process which forms a blood clot at areas of endothelial damage or vascular injury to stop bleeding and facilitate repair of the injured site
haemostasis
primary hemostasis consists of these two phases
vascular phase and platelet phase
what two components are involved with primary hemostasis
blood vessels and platelets
these are small anucleated cytoplasmic fragments of megakaryocytes
platelets
the main growth factor that regulates production of platelets is this
thrombopoietin (TPO)
this is the main initial response following injury to a blood vessel to reduce and slow blood flow; it is caused by contraction of smooth muscle of the vessel wall due to local natural reflexes
vasoconstriction
reduced blood flow allows these to accumulate at the site of injury in blood vessels
platelets
the platelet phase of primary hemostasis consists of a series of processes that lead to the formation of this
platelet plug
this is one of the main components involved in platelet adhesion; found in plasma and in the sub-endothelium
von Willebrand factor (vWF)
what two things happen when platelets are activated
- undergo a shape change
- release their granular content
name 2 anticoagulant factors synthesized by normal endothelial cells to prevent coagulation
nitric oxide (NO) and prostaglandin I2 (PGI2)
coagulation factors during secondary hemostasis are mostly produced by this organ and circulate in the blood in their inactive forms
liver
what element is required for nearly all the reactions in the coagulation cascade
calcium
this is the final product of the coagulation cascade, which strengthens the platelet plug and stops further hemorrhage
cross-linked fibrin
what are the two branches or pathways of the coagulation cascade
intrinsic and extrinsic coagulation pathways
in vivo coagulation is mainly initiated by exposure of this, expressed on sub-endothelial cells such as fibroblasts and smooth muscle cells
tissue factor (TF)
in this pathway of coagulation, small amount of thrombin amplifies its own production by activation of factor XI
intrinsic pathway
this pathway of coagulation rapidly generates small amounts of thrombin
extrinsic pathway
in this pathway of coagulation, there is generation of thrombin, which then cleaves circulating fibrinogen to generate fibrin monomers - activate factor XIII which catalyzes the formation of bonds between adjacent fibrin monomers to generate cross-linked fibrin
common pathway
this is an important anticoagulant factor that is complexed with heparin molecules produced and associated with endothelial cells ; it is the major thrombin inhibitor
antithrombin (AT)
this causes dissolution of the fibrin clot once the damaged blood vessel is repaired, which re-establishes normal vascular potency
fibrinolysis (tertiary hemostasis)
fibrinolysis is mostly activated by this, which is released by damaged endothelial cells - it activates plasminogen to plasmin
tissue plasminogen activator (tPA)
