Quiz 4 Flashcards
(91 cards)
Megalocyte contains 3 embrionic forms
Megalocyte embryonic forms are:
1-Glower 1:
2-GLower 2: 5-12 weeks
3-Portland 5-12 weeks
Fetal HGB
HGF
Fetal HGB has 2 alphas & 2 Gamma
Adult HGb has 2 alpha and 2 Beta
Begins to form 6-12 weeks GA
Higher affinity for O2-Does not release Oxygen readily
Does Not contain 2,3 DPG
(our cells don’t have a higher affinity for oxygen, so it’s not a problem for us)
BUT in the fetus, holds on and shifts to the left requiring higher concentrations of oxygen before they will release it
vasoconstriction
when you have physical injuty to a blood vessel
-contractile response narrowing the vessel
occurs by direct mechanical stimulation
-small arterioles or arterie-the lumen of the BV actually closes and stops the bleeding
PT > 17 seconds at any Gestation
AND a PTT -45-50 in term infants is a concern
PTT measures ALL factors except XIII & XIII
abnormal if any factor is 20-40% of normal
failure to give vitamin K
causes bleeding diathesis at 3-4 dys of age
=use of abx may decrease/interfere with prodution of vitamin K
Process of RBC Development
Same in the hepatic and myeloid period
Erythropoietin pkays a part-it stimulates stem cells to become precursor of hte erythrcytes
-Stem Cells differentiate into early and late
Production of cells
Eosinophils at 10-21 weeks
basophils at 10 weeks
Macrophages 10-16 weeks
Monocytes 12-16 weeks
T-Lymphocytes at 7 weeks
B-Lymphocytes at 8 weeks
Hepatic Period
THis is how the liver takes on the production of blood cells
- 1 1/2 months and peaks at 3-5 months thru 10 months
- Spleen-Contributes at 2 1/2 months
- peaking at 4 month
- and then decreasses by the end of the 4th month
- By the end of the 4th moth, the spleen will contribute to the production of
1-lymphocytes
2-erythrocytes
Mast Cells
Found in Bone Marrow, spleen and Thymus
Similar in appearahce to basophils
RELEASE HISTAMINE IN RESPONSE TO TISSUE DAMAGE
when histamine is released, leads to reddening ad warming of skin
other substrated released include K+, bradykined, serotonin and prostaglandin
K+ is released by dying tissue
bradykinen activates pain receptors
PGE-sonstriction of smooth muscle
All participate in inflammation response
IgG
Only class that crosses the placenta
Produced and Synthesized 10-12 weeks GA
A 30 weeks, secretory IgA appears
IgG offers protection the 1st few months of life
Mose importand immunoglobulin
tranferred from mother to infant
granulopoietin
Neutrophils
is important for granulocyte production
regulates granulocyte production
-controls movement from the bone marrow to the blood of the neutrophil;
those that are not needed, adhere to art of the vessel wall i the marginal pool and they stay there util they are needed
-mature neutrophils -50% circulate freely in circulation and 50% adhere to the wall of the vessel and remain part off the marginal pool
Cells that are attatched to the vessel wall are not included in the WBC count
the differential only represents half of the circulating
-when there is a demand for neutrophils, the mature cells are released first and if there isn’t enough, there in an increase in the # of bands
Hepatic Period
- 1 1/2 months
- peaks 3-5 months thru 10 months
- begins with RBC production in the embryonic Liver
- Stem cells migrate from the yolk sac to the Liver
- Some stem cells migrate to the liver that arise indelendently and not from the yolk sack
- Liver grown Rapidly from 7-8th week
- by the 9th week, the liver accounrs for 10% of the total body weight of the fetus (liver is the main organ that’s producing blood cells)
Myeloid Period
production of all cells escalate
- we will see mature RBC week after marrow develops
- significant quantities by 17 weeks
Mature RBC’s Do NOT have a nucleus
(CFU-E) differentiate into a normoblast, gain HGB and become a retic
Immature RBC’s DO HAVE a nucleus
-once it is 34% concentrated, the nuleus goes away making immature retic and then 1-2 days later, the RBC is mture
Retics are immature RBCs
HGB Levels
term-lowest at 8-12 weeks (11.4)
preterm - lowest at 4-8 weeks (7-10)
not prevented by supplements
Heematopoietic stem cells are precursors to/for
-erythrocyte
lymphocyte
granulocyte
monocyte
megakaryocyte
megakaryocytes are precursors or platelets and are preset in the liver at 5-6 weeks
-platelets can be found in the blood by 11 weeks GA
FIBRINOLYSIS
USED IN MI PATIENTS; DOSOLVES CLOTS
CLOT LIQUIFIES DUE TO PLASMIN (PROTEOLYTIC ENZYME)
Erythropoietin
After birth, the EPO levels decrease dramatically du to an increase in PaO2 levels relative to the levels the fetus was exposed to in utero
- later because of tissue hypoxia, we will see an increase in EPO production, resulting in physiologic anemia (3rd week in term and end of 2 week in preterm)
- Physiologic anemia increases the production of EPO
ANC
=% SEGS = 5OF IMMATURE CELLS (metas, Myelos, bands) x WBC
ANC < 1350 suspect infection
parameters
RBC- 4.6-5.2 milliom/mm3
Nucleated RBC can be seen in the NB’s first 24 hours
Stress at delivery affect the # of RBC’s present
(as more immature rbc are being produced and disappear within ays in term and by 1 week in preterm)
when do platelets start circulating?
by 8 weeks
increases with GA
WBC-Myelopoiesis
1-produced in the bone marrow and lymphatic tissue thru the promeylocyte, myelocyte and metamyclocyte stages
2-enter circulation at the polymophonuclear stages as pMC as neutrophils
3- WBC’s are carried in the circulation to extravascular rissues-part of the immature system
4-Myelopoiesis is associated with WBC production and hematopoiesis/erythropoiesis is associated with RBC production
5)-development of WBC’s
Mylecopoieses begins
RBC’s 1st them WBC’s
T-Lymphocytes
release lymphokines that recruit phagocytes, stimulate lymphocytes and macrophages which inhibit viral repication
a) interferon
b) interleukin
are the most familiar types or lymphokine
