Blood and Anemia Flashcards
What is the composition of blood?
plasma (55%):
-water (92%)
-proteins (7%)
-salts
-lipids (cholesterol)
-carbohydrates (glucose)
-gases (O2, CO2)
cells (45%):
-RBC (4.5million/mcL)
-WBC (5000-10000/mcL)
-granulocytes
-neutrophils (60-70%)
-eosinophils (1-3%)
-basophils (1%)
-monocytes (4-8%)
-lymphocytes (20-40%)
-platelets (150,000-400,000/mcL)
What is the hematocrit?
volume fraction that is cells after centrifugation
What are the sites of hematopoiesis in adults? Children? Fetus?
adult: calvarium, vertebrae, ribs, sternum, pelvis
child: bones
fetus: bones, liver, spleen
What is the basic cell of the eight major hematopoietic lineages? What can this cell differentiate into?
stem cells
stem cells can become CLP or CMP
CLP–>T cell or B cell
CMP–>RBC, platelets, basophil, eosinophil, neutrophil, monocyte, osteoclast
Describe the intrinsic pathway of the coagulation cascade.
starts with vessel damage
XII–>XIIa
XI–>XIa (via XIIa)
IX–>IXa (via XIa)
X–>Xa (via XIa)
II–>IIa (via Xa)
fibrinogen–>fibrin (via Xa)
Describe the extrinsic pathway of the coagulation cascade.
starts with trauma
VII–>VIIa
X–>Xa (via VIIa)
II–>IIa (via Xa)
fibrinogen–>fibrin (via IIa)
What makes up the common pathway of the coagulation cascade?
Xa
What is the role of anticoagulants?
reduce the risk of blood clots which can cause stroke, pulmonary embolism or MI in patients with AF, VTE, ACS, orthopedic surgery
What is the MOA of warfarin?
blocks the vitamin-K dependent processes of producing factors II, IX, VII, X
INR monitoring is essential
Which clotting factor is prothrombin?
II
What is the MOA of apixaban, rivaroxaban, and edoxaban?
factor Xa inhibitors
What is the MOA of heparin?
binds to and activates antithrombin, inactivating factor Xa and IIa
may be used during acute DVT and MI management
What is the MOA of enoxaparin and LMWH?
reduced anti-factor IIa activity relative to anti-factor Xa activity
more favourable benefit-risk ratios
better PK
less microvascular bleeding and bleeding risk compared to UFH
What is the MOA of dabigatran?
direct thrombin inhibitor
True or false: ASA is an anticoagulant
false
its an antiplatelet, sometimes used in combo with DOACs
What are examples of antiplatelet drugs?
platelet aggregation inhibitors:
-ASA and COX-inhibitors
oral thienopyridines:
-clopidogrel, prasugrel, ticagrelor, ticlopidine
glycoprotein platelet inhibitors:
-abciximab, eptifibatide, tirofiban
protease-activated receptor-1 antagonists
-vorapaxar
miscellaneous:
-dipyridamole (nucleoside transport inhibitor and PDE3 inhibitor)
-cilostazol (PDE3 inhibitor)
What is the function of erythrocytes?
transport of oxygen from lungs into peripheral tissues
What is the structure of hemoglobin?
four heme groups and four globins
-adult: two alpha, two beta
-fetal: two alpha, two gamma
What is anemia?
reduction of hemoglobin in the blood to below-normal levels
-<13g/dL in males
-<11.5g/dL in females
What might anemia be associated with?
abnormal hemoglobin: abnormal hematopoiesis
reduced # of RBC: decreased hematopoiesis
structural abnormalities of RBC: abnormal hematopoiesis
may be a consequence of increased loss or destruction of RBC
Which vitamins, minerals, and macronutrients could be associated with decreased hematopoiesis?
iron deficiency
vitamin B12 deficiency
protein deficiency
What is a genetic disorder that can cause abnormal hematopoiesis?
sickle cell anemia
What are examples of bleeding that can put a person at risk for increased loss or destruction of RBC?
prolonged menstrual bleeding
peptic ulcer
What is the morphology of a normal RBC?
biconcave disk
7mcm
Provide morphologies of RBC and an example with each.
normocytic, normochromic anemia
-dilutional anemia
microcytic, hypochromic anemia
-iron deficiency
macrocytic, normochromic anemia
-deficiency of B12 and/or folic acid
anemias associated with abnormal RBC shape:
-elliptocytosis, spherocytosis, sickle cell anemia
Provide examples of the many different symptoms of anemia.
eyes: yellowing
skin: pale, cold, yellowing
respiratory: shortness of breath
muscular: weakness
intestinal: changed stool color
central: fatigue, dizziness, fainting (severe cases)
blood vessels: low bp
heart: palpitations, tachycardia, angina or MI (severe)
spleen: enlargement
What might cause decreased hematopoiesis?
bone marrow failure
-aplastic anemia
-myelophthisic anemia
deficiency of nutrients:
-B12 and folic acid (megaloblastic anemia)
-protein
What usually causes abnormal hematopoiesis?
genetic abnormalities
-sickle cell anemia, thalassemia
What might cause increased loss and destruction of RBC?
bleeding
intrasplenic sequestration
immune hemolysis
infections (malaria)
hemolytic anemia
Describe hemolytic anemia.
increased RBC destruction
intracorpuscular defects:
-structural abnormalities
-sickle cell anemia, thalassemia, hereditary spherocytosis
extracorpuscular defects:
-antibodies, infectious agents, mechanical factors
What is the most common form of anemia?
iron deficiency anemia
What is the etiology of iron deficiency anemia?
increased loss of iron (chronic bleeding)
inadequate iron intake or absorption
increased iron requirements:
-babies, adolescents, adult women, pregnant women
True or false: folate is a fat-soluble vitamin
false
water-soluble type of vitamin B (B9)
What are sources of folic acid?
green leafy vegetables
citrus
pulses
What is the role of folate?
folic acid works with B12 and vitamin C in protein and DNA metabolism
formation of red and white blood cells
What are contributors to folate deficiency?
diseases in which folic acid is not well absorbed
-Celiac or Crohns
excessive alcohol
overcooked fruits and veg
hemolytic anemia or kidney dialysis
medicines (phenytoin, sulfasalazine, TMP/SMX)
True or false: WBC disorders are usually a result of abnormal function
false
usually a result of abnormal number
What might cause neutrophilia?
increased marrow activity:
-bacterial infections
-acute inflammation
-leukemia
release from marrow pool:
-stress
-corticosteroids
-endotoxin exposure
demargination into blood:
-bacterial infections
-hypoxemia
-stress
-corticosteroids
-exercise
What might cause neutropenia?
decreased marrow activity:
-drugs
-radiation
-megaloblastic anemia
-aplastic anemia
-marrow replacement by tumor
decreased neutrophil survival
-sepsis
-viral or rickettsial infection
-immune destruction via drug
-immune destruction via antibodies
What might cause lymphopenia?
immunodeficiency (AIDS
corticosteroids
toxic drugs
Cushings
What might cause lymphocytosis?
medium to large, atypical lymphocytes predominant:
-viral infections
-active immune response
-lymphoma, leukemia
small, mature lymphocytes predominant:
-chronic infections (TB)
-autoimmune diseases (myasthenia gravis)
-metabolic diseases (Addisons disease)
-lymphoma, leukemia
immature cells predominant:
-leukemia, lymphoma
