Exam 3 Flashcards
Erythrocytes have what two unique properties:
- Biconcave shape
- Capacity to be reversibly deformed
Biconcave shape increases… on RBCs
Surface area
RBCs that have abnormal shapes
Poikilocytosis
RBCs that have abnormal sizes
Aniscocytosis
What is poikilocytosis
RBCs have abnormal shapes
What is anisocytosis
RBCs have abnormal sizes
Biconcave shape of RBCs allows for better…
Gas exchange
RBCs with their reversible deformity allow for
Diffusion of oxygen and squeezing through the capillaries
What type of anemia
RBCs are abnormally large and not fully developed
Megaloblastic anemia
What type of anemia RBCs
Bone marrow produces fewer cells and sometimes they die before 120 day lifespan
Megaloblastic anemia
Pernicious anemia is an example of what type of anemia
Megaloblastic anemia
What is the main disorder in pernicious anemia
Absence of intrinsic factor
What vitamin is deficient in pernicious anemia
Vitamin B12
A glycoprotein produced in the stomach that binds with vitamin B12 so that it can be absorbed in the intestines
Intrinsic factor
If the stomach doesn’t produce enough IF what happens?
The intestines can’t properly absorb vitamin B12
Leads to vitamin B12 deficiency
What doesn’t mature properly in RBCs in pernicious anemia?
The nucleus
In PA RBCs
Three characteristics
A
Wrong shape
Wrong size
Die more quickly
Mechanism by which medications cause pernicious anemia
Some medications block IF or stop it from working properly
Older adult presentation of pernicious anemia
Neuropsychiatric disorders
Cognitive impairment
Fix with B12 shots
Reduction in total number of erythrocytes in circulating blood or a decrease in the quality or quantity of hemoglobin
Anemia
Anemia is either a decrease in
Total number of erythrocytes in circulating blood or
Decrease in quality or quantity of hemoglobin
Four causes of anemia
1) impaired erythrocyte production
2) blood loss- acute or chronic
3) increased erythrocyte destruction
4) a combination of above three factors
When is DNA synthesis impaired in megaloblastic anemia
During RBC production
Impaired DNA synthesis prevents what in megaloblastic anemia
Further nuclear division