Hem Pathology Flashcards
(37 cards)
What are the two main causes of Vit B12 anemia
Inadequate intake & Impaired Absorption
What is pernicious anemia
Type of Impaired Absoprtion Vit B12 anemia, due to intrinsic factor deficiency
What are lab values found with vit B12 anemia
low B12, high MCV, low Hgb
What are two MACROphagic anemias?
Vit B12, Folate
What is another name for Anemia of Chronic Disease (ACD)
Anemia of inflammation (AI)
What is the cause of ACD?
decreased erythropoiesis and impaired iron utilizations as a result of chronic disease
What is the cause of sickle cell anemia
decreased life span of sickle cells (10-20 days instead of 90-120)
What are the causes of IDA
dietary deficiency, impaired absorption, increased requirement, chronic blood loss
what lab values are expected with IDA
Low Fe, microcytic-hypochromic RBCs on blood smear
How does anemia affect the cardiac system
1.decreased RBCs = decreased viscosity and volume of blood so interstitial fluid moves into intravascular space to expand plasma volume further decreasing viscosity, creating a hyperdynamic circulatory state as thin blood flows faster = INCREASED STROKE VOLUME AND HR
2.hypoxia leads to dilation of arterioles/capillaries, further contributes to hyperdynamic circulatory state and increased sv&hr - leads to heart failure
how does anemia affect the respiratory system
tissue hypoxia increases rate and depth of breathing - dyspnia, palpitations, fatigue
What is the intrinsic pathway in the coagulation cascade?
XII –> XI –> IX –> VIII (12,11,9,8)
then common pathway
What lab test is used to measure intrinsic pathway?
aPTT
What is the extrinsic pathway in the coagulation cascade
TF(tissue factor/F3) and VII (7) lead to common pathway
What lab test is used to measure the extrinsic pathway
PT
What is the common pathway?
1.Factor X interacts with FV, Ca & lipids to convert prothrombin (F2) to thrombin (F2a)
2.thrombin turns soluble fibrinogen (F1) into insoluble fibrin by linking particles together into chains
3.Factor XIII then takes insoluble fibrin and cross-links it to stabilize it into fibrin mesh which holds platelet plug in place
What is factor 2?
inactive = prothrombin
active = thrombin
What are the two ways coagulation is inhibited
inhibition of thrombin formation & fibrinolysis
How is thrombin formation inhibited
- thrombin activates protein c (APC)
- APC combines with Protein S to slow down F5a and 8a
- Thrombin becomes inactive
- antithrombin inhibits further thrombin
How does fibrinolysis occur
Tissue plasminogen activatory (T-PA) converts plasminogen to plasmin, which breaks down fibrin
(shows up as Ddimer)
what is antithrombin
glycoprotein synthesized in the liver that inhibits factor 2a (thrombin), factor Xa, and to a lesser extent F11a adn 9a.
(half life 2-3 days)
what is d-dimer and what does it indicate?
d-dimer is a biproduct of fibrinolysis - high levels indicative there may be a blood clotting condition
what is C-reactive protein (CRP) and what does it indicate
CRP becomes active when contacts thrombin, helps to slow down coagulatin process
HIGH LEVEL = INFLAMMATION
what percentage do erythrocytes/plasma/buffy layer make up in blood
RBC=45%
plasma = 55
BL=<1%
