Quiz 4 Flashcards
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
Vitamin K
respinsible for carboxylation of glutamine acid residues in amino acid terminal portion ofprotein molecule
-study clotting factors; learn that ca+ is important in the clotting process
cannot have appropriate clotting without ca+, so carboxilation
- results in allowing protein to bind with Ca+ions and converts factors to thrombus formation
- needed for thrombus formation
brotein to bind with Ca+ ions converts factors to thrombus formation
-glutamic acid coe=mes from glutomate which is essential amino acid
Reticulocytes Become
MATURE RBC’s
Normally takes 48 hours for retic to become ature erythrocyte
- mature erythrocyte DOES NOT have a nucleus
- Nucleus is lost when the HGB becomes 34% saturated with Oxygen
PMN
SEGS
Polymrphonuclear
segmented neutrophils
mature neutrophils
sometimes called poly’s or segs
immature forms seen in healthy NN first 2-3 days of life
Cachectin
TNF
Tumor necrosis factor
responsble for fever
a) macrophage hormone
b) produced in the presence of endotoxin
c) inhibits the triglyceride clearance and faulty lipid metabolism
Compromises nourishment of bacteria and alters lipid metabolism
Causes muscle wasting
Negative nitrogen balance
Erythrocyte Indices
MCV=Mean Cell Volume=average size and volume of a single RBC
a) MCV decreases as GA progresses
b) normal range = 107-120
Increase MCV-MACROCYTE
Decreased MCV-MICROCYTE
I:T
Band to seg ration in amarillo >.3
Blood sampling
how/where site can lter the values
cap hgb values 2-3 greater than venous
arterial hgb are 0.5 greater than venous
hgb, hct and RBC-heelstick is 5-25% higher than venous or arterial
WBC counts
crying increases and can shift to the left
arteria
Neutrophils are non-specific
best defense a baby has because there isn’t enough immunoglobulin IgG (mom to baby in last trimester, baby may not get enough if preterm)
2 types of T-Lymphocytes
Helper and supresser
1-Helper-stimulate helper cells which stimulate antibody production
2-supresser T Cells-turn off antibody reactions
BLOOD CLOTTING
complex process
cascade of reactions
-factors are synthesized inn liver as Vit K
Vit K clotting factors given after delivery
RBC Development
RBC Production is regulated by EPO
-EPO doesn’t cross the placents (baby has to produce own EPO)
EPO increases 19 weeks to term
From 20 weeks-EPO is Primarily produced in the liver, rather than the kidney
FROM 30 weeks on, the fetus reacts to hypoxia with Increased EPO production
Lymphocytes
Are initially produced in the fetal liver and lymphoid tissue, then to thalmus, spleen and then to the bone marrow
Neutrophile Stages of Development
Promylelocytes stage-cells produce NONSPECIFIC granules
Myelocyte Stage: Specifi Granules are Produced
Metamyelocytes: spends 7-8 days ina strage pools before it matures
Neutrophils-Dont require previous exposure to an antigen-they just destroy it
IgM & IgA
Directly responsible for antibodies against bacteria NOT passively transferred from placenta
-Secretory IgA is an early defense against local infections-present in Human Milk
Erythrocyte Maturation
RBC’s undergo specific changes in composition during hematopoieses
Stem cell
*
Precursor Stages
*
Reticulocyte
*
Mature RBC
PRECURSOR STAGES: are mesoblastss and megaloblast
Thymus and Lymph Nodes
4th month
Peaks at 6 months and continues
-primarily involved with the development of lymphocytes
(which is Lymphopoiesis)
Immature WBC’c Develop
Monocytes
“Quite Important”
- slightly inrease during the first 12 hours after birth, then decrease
- transformed into macrophages in the tissues (lungs, alveol
2- THe ACTION of the monocyte-lears id blood cells, cellular debris opsinized bacteria, antigen, antibody coplexes and activating clotting factors
DEVELOPMENT OF WBC’S AND PLATELETS
development of WBC & Platelets
-begins in the liver at 5-7 weeks
Spleen at 8 weeks
Thymus at 10 weeks
Lymph Nodes at 12 weeks
capilarry vs venous
more marked with decrease GA and after large transplacental transfusion, infants with acidosis, hypotension and severe anemia
NATURAL KILLER CELLS
cells lack immunologic specification
T-Lymphocytes but lack any characteristics of T or B Cells
kills cells of any origin or microbial strain or species
Retic count = ## of immature RBC’s to the total RBC’s
a) expressed as a %
b) 28 wks 5-10%
c) 34 wks-3-10%
d) full term 3-7%
e) 1 week post term 0-1%
Erythrocyte Indices
MCHC: Volume of Hgb in average RBC 31-36% of adult calues at 6 months
MCCHC
Mean corpuscular hgn CONCENTRATION
Concentration if hgb per sincel rbc calculated from the amount of hgb/100ml of cells
Increase and decrease same as MCH
PLATELETS
- small, non nucleated, dic-shaped cells
- aid in homeostasis, coagulation and thrombus formation
- derived from megakaryocytes in bone marrow
circulate 7-10 before removal
- in the absence of injury, they circulate freely without adherence or aggregation with other platelets
- normal value 100k-300k
15% pretemn levels > 150k first month
Clotting pathways
intrinsic-activated by vascular tissue injury-damage to endothelium
-Extrinsic-activated by epithelial cell injuty and release of thromboplastin
Both converge on activation of Factor V-cleage of prothrombin and thrombin
=ll intrinsic factors are decreased in NB
-activity further decrease with GA
HCT
Volume of RBC’s found in 1 dl of blood
a) expressed as a %
b) 51-56% ranges
c) Hct increases after first few hour
(Intravascular to interstitial space)
When needed, there are bands
it takes a while for the bands to mature
so, in addition to mature neutrophils being released, we have immature neutrophils (bands) released
1st the mature, then the immature
HGB
Influenced by GA and birthweight
a) higher in NB (16.6-17.5)
b) increases by 6 g/dl in first 24-48 hours
c) decreases by end of the first week
d) higher levels seen in infants with hypoxiam IUGR, Post-term (influenced by GA and birthweight)
e) lower levels found in preterm infants (15.9)
f) increase in reticulocytes or # of nucleated RBC’s suggest compensation and may indicate anemia ( check H&H, retics and HX…? hemolytic disease)
g) persistent reticulycytosis (increase in anount of retics) may indicate chroni blood loss or hemolysis
h) RBC=# mature RBC
i) nucleated RBC=# immature RBC’s present
Homeostasis
Arrest from bleeding
3 processes
a) vasoconstriction
b) platelet aggregation
c) blood clotting
B-Lymphocites
Humoral Immunity
Proliferation and maturation is iniatiated by specific antigen and helper T-Cells
=Stimulation then differentiation into plasma cells
=plasma cells produce immunoglobulins
_b-lymphocytes, plasma cells and antibodies are all a part of humoral immunity
Their FUNCTION is to synthesize speific immunoglobulins’
Platelets
Initially formed in the yolk sac at 5-6 weeks
at 8 weeks in liver
and circulating Increases in number of platelets with GA
Life Span of the RBC
Adult = 100-120 days
Full term = 60-70 days
preterm = 35-50 days
There is a differention due to a large size of the RBC in preterm infant and cylindrical shape make cells more prone to destruction by the spleen
One of the most important defenses in neonatatal Function
NONSPECIFIC PHAGOCYTOSIS
CBC and Differential
a) In wbc-Nucleated RBC couned as WBC;s
formula to correct wbc
Total WBCx100
ofNRBC +100
= Corrected WBC
Ig1 and Ig3
do not respond to a specific Antgen
a) acts as opsonins
b) opsonization_coats antigen so it’s unrecognizable so that it can be taken care of by the neutrophils, PMS, monocytes and macrophages
- brings all of these bacteria fighting cells to the antigen
c) non-specific antigen fighter; enhances protection
Granulocytes
Eosinophils
Eosinophils
a) same functions as neutrophils (phagocytosis)
b) present when there is an allergic or anaphylactic rection
c) benign eos of prematurity may be seen in ifnats who receive TPN Blood or with ETT intubation
d) 1-3% of total WBC
cap and venous=poor circulation and vensous stasis
arterial vs venous=passage of plasma to interstitial space in capilarry bed
Myeloid Period
Begins at 4 months
- bone marrow that is now the main producer of bloodcells
- maun area is the fatty area in the core of the long bones-
- long bones in the fetus and NB are cartlinageous, so ther eis a small marrow volume
so, if there needs to be a production of RBC/s, then the liver and spleen can be reactiated to help produce RBC’s
-tht’s why there is overlapping of the mesoblastic, hepatic and myeloid periods of production; it’s a safety net
continues to increase the production of blood cells thru out life
factors dependent upon Vit K for synthesis
4 factors II, VII, IX and X
Protein C-protease antocoagulant
Protein S-Cofactor for activation of Protein C
Erythrocte indices
MCH- mean cell corpuscular HGB
- Average amount or WEIGHT od single HGB/RBC
a) paallels decrese in MCV
b) increase MCH-Hyperchromic
c) decrease MCH Hypochromic
Mesoblastic period
14-19 days
peaks at 6 weeks
- blood cells formed in blood islands in the secondary yolk sac
- Primitive cells in the island form primitive blood vessels
- blood forms in the yolk sac until the 3rd month of gestation
LYMPHOCHTES
Thymus driven
T-Lymphocytes
a) envolved with hypersensitivity reaction-graft vs host and delayed hypersensitivity response
Bone Marrow Derived “B”
a) responsible for production and secretion of immunoglobulins and antibodies
Hematologic system arises along with the CVS
CVS earliest system to fx
Blood cell production occurs in 3 phases
- Phases Overlap
- During each phase
- there are alterations in the cell composition
- Changes in the site of the production of cells
3 Stages
1-Mesoblastic Period
2-Hepatic Period
3-Myeloid Period
Neutrophils are NOT specific
recognize invader organism as foreign
HGF
-30 weeks-90-100%
30-32-% of HGF decreases and HGA increases
40 weeks: 50-75% HGF
6 monthd 5-8%
1 yr is 1%
Platelet aggregation
damage to the endothelium of blood vessels causes platelets to adhere to each other
- releases adp and A2 (causing adherence)
- Continues until BV become blocked by a mass of aggregate platelets;
NN at a igher risk for bleeding due to platelet aggrefation to to a decrease in thrombaxanw A2
Release of Neutrophils
Seem to be Controlled by colony stimulating factor and granulopoietin
GRANULOPOIETIN IS IMPORTANT FOR GRANULOCYTE PRODUCTION
POLYCYTHEMIA AND HYPERVISCOSITY
polycythemia > 65% or Hgb >22
due to chronic hypoxia, fluid shifts and delayed cord clamping
response: increae EPO production (growth restriction and Increase hyperbilirubinemia)
WBC’s include
GRANULOCYTES
(neutrophils, eosinophils, basophils)
LYMPHOCYTES
MONOCYTES
Normoblast gain Hgb and become mature RBC’s
When the HGB concentration reaches 3
%, the nucleus of that cell is lost and the cell then becomes a reticuocyte (immature RBC)
1-2 days later, after the reticulocyte is produed, the retic becomes a mature RBC
PROcess of RBC
Burst forming units come first (BFU-E)
Colony forming units (CFU-E)
Then (CFU-E) differentiate into microblast, gain
CFU-E=differentiates into normoblast, gain Hgb and become mature RBC’s
antivoagulants
remove CA+ ions from solutions’inhibit synthesis of Vit K dependent factors
T-Lymphocytes-
Make up cell mediated immunity
respond to specific antigens
major histocompatibility complex antigens-are responsible for recognistion of foreign antibodies
full term and pre term infants-have decrease clotting factors
facots V & VIII are higher than adult values but decrease in infants <31 weeks
the more preterm, the less/lower the clorrig ffactor
and a decrease in functiona ability of fibrinogen, so they have a decrease in the abiluty to form clots
Granulocytes
Neutrophils
Most abundant
60% total WBC
a) main job is phagocytoses
b) production is increased with stress
c) increases at burth, then decreases
d) 1st phagocytic cells ro reach the infected area
e) stages of development
Myeloblast
Promyelocyte
Myelocyte
metamyelocyte
Band
PMN
Lymphocytes
Lymphocytes
Initial produced from the liver and lumph tissue
- from the thymus at 7-10 weeks
- spleen and bone marrow at 10 weeks
CBC
2/3 infectious have a NL CBC
diagnostic CLUE
WBC 1st cell to reach the site of infection
need a diff
low counts are more common than high ones
Left shift as reference to predominance of immature forms (myelos, meta, bands)
Remember that the liver is still producing RBC and if the fetus needs more RBC’s, then the liver can produce and the spleen will kick in causing
HEPATOSPLENOMEGALY
because it’s working overtime to produce blood in there is maternal fetal incomatabilities
Erythroblastosis Fetalis
causes hepatosplenomegaly
Bone Marrow is the major site for blood production AFTER 6 months of age
Will produce granulocutes and megakaryocytes
occurs in the long bones; liver and spleen can kik in to help
Immunoglobulins
5 types
Synthesized in response for specific antigens
IgG
IgM
IgA
IgD
IgE
Fibrinolysis activity
Increases at birth
decreases to adult values by 4-6 hours of age
can be severely depressed in the preterm infants with RDS and asphyxia
physiological anemai
in both FT and PT
normal decrease in HGB first 2-4 months
-due to supression of hematopoiesis wich is controlled by erythropoitin
cause-supression of hemapoietin and RBC production decrease
balanced by a gradual shift to the right in OxyHgb curve due to increaeing amounts of 2,3 DPG
reestablished when tissue needs more o2
GRANULOCYTES
BASOPHILS
1 Basophils-important in inflammatory response
a) least numerous
b) .1-1% of total WBC’s
c) fuction is Chemotaxis, phagocytoses
released by histamine producing cells
participates in delayed hypersensitivity reactions
In infants, there is a PROLONGED
PT
TT
PTT
Neutrohils:
in circulation replaced 25 times every 24 hours
Do not return tot he bone marrow
randonly enter the tissues and will engulf and kill backeria where needed
Margical pool-from the marginal pool, neutrophils will eter tissues and the body to carry out their function
in NN, whole blood clotting times are = or shorter than adult values DESPITE prolonged PT, PTT and TT
REASON:
overbalance or tendency of thrombus formation despite normal clotting times
DETERMINE Ca+ LEVELS; CA+ IS AN INSITE INTO WHETHER THERE IS A CLOTTING PROBLEM
