Blood Part I Flashcards
Structural cytosolic fibrous protein in erythrocytes
Spectrin
Type of ATP production in RBCs
Anaerobic glycolysis - no oxidative phosphorylation
Role of carbonic anhydrase in RBCs
Assists in loading C02 onto RBCs for transport
Components of hemoglobin molecule
One globin and 4 heme groups
How many molecules of 02 can one hemoglobin carry?
Four
What does hemoglobin carry?
O2, CO2, H+, CO
What are the effects of a leftward shift in the oxygen-hemoglobin curve?
Increased affinity for easier loading and harder unloading
What are the effects of a rightward shift in the oxygen-hemoglobin curve?
Decreased affinity for harder loading and easier unloading
What are the effects of increased body temperature on Hb?
Decreased affinity for O2, and easier offloading at tissues
Effects of pH on Hb: pH decreases and [H+] increases causes….
H+ produced in active tissues bind to Hb and decreases affinity, making unloading easier
Effects of CO2 on Hb
CO2 reacts with Hb to form HbCO2, which has a lower affinity for O2, increasing unloading of O2
Effects of 2,3-DPG on Hb
Decreases affinity of Hb for O2
When and where is 2,3-DPG produced?
In RBCs under low O2 conditions
Type A Hb consists of what types of chains, and is most predominant type in who?
2 alpha chains and 2 beta chains, and most predominant type of Hb in infants, kids, adults
Type F Hb consists of what types of chains and is most predominant in who?
Alpha and gamma chains, and most predominant in fetal blood
What is the advantage of Type F Hb
Greater affinity for O2, which allows for abs of O2 at lower PO2
Type S Hb: causes, differences, effects
Caused by a.a. sub in beta chain, causing sickle shape, and hemolyzes easily which causes anemia and RBCs to get trapped in capillaries
What is the name and location of the process in which RBCs are synthesized?
Erythropoiesis in red bone marrow
What substances are required for erythropoiesis?
A.a., iron, vitamins B2, B12, pyridoxine, and folic acid
Common precurser for erythrocytes and leukocytes
Hematopoietic stem cells
What stimulates erythropoiesis?
Erythropoietin
When is erythropoietin secreted and from where?
Secreted from kidneys when blood O2 is low
Two causes of anemia
- Reduced RBC count
2. Reduced amount of Hb in blood
Levels of Hb and Hct to be considered anemic
Hb < 12 g/100ml
Hct < 37%
Causes of iron deficient anemia
Lack of dietary iron, inadequate absorption, loss of iron stores
Definition of aplastic anemia
Decrease in production of all blood cells
Causes of aplastic anemia
Radiation, cytotoxic drugs, exposure to chemicals, and genetic failure
Definition of hemolytic anemia
Occurs when rate of RBC destruction > RBC production
Causes of hemolytic anemia
RBC defects (ie. sickle cell) or damage to RBCs (ie. runners anemia)
When do symptoms manifest in heterozygous sickle cell anemia?
Only in the presence of unusually low [O2]
Causes of thalassemias anemia
Inherited disorders that limit rate of alpha or beta chain synthesis
Causes of hemorrhagic anemia
Acute or chronic blood loss
