Erthrocyte Physiology Flashcards
Functions of blood
- Deliver nutrients and O2
- Remove waste
- Maintain homeostasis
- Circulation
- Thermoregulation
- Immune response
What is the hematocrit formula
Height of RBC’s/ total height
Normal hematocrit range
40%-45% adult
55% for newborn
RBC function
- Carry O2 to body
- Carry CO2 to lungs
- Acid/base buffering
Globulins are not made in
The liver
What is cyanosis
Blue color in lips and skin
-from decreased oxygen in hb
Hematocrit is
% of blood that is cells
Where does erythropoiesis occur
Bone marrow
Will damage to the kidney cause anemia
Yes
*bodies use oxygen levels in kidneys to determine how many RBC’s we need
What is the function of hypoxia inducible factor (HIF)
*regulates amount of oxygen in body by interaction with kidney
- if O2 is adequate then it is ubqinuated and destroyed
- if O2 is low then it accumulates and acts as an transcription factor to increase erythropoietin gene to make RBC and transferrin to get more iron
Where is erythropoietin produced? Released to ? And brought for action?
Kidneys
Liver
Bone marrow
What does erythropoietin do ?
*JAK2/STAT5 pathway
- acts on stem cells (differentiate to proerthyroblasts)
- increases maturation of RBC precursors
- prevents apoptosis of erythroid stem cells
*MAKES RBC’s
How may oxygens can bind to hemoglobin
4
The _______ influences how well oxygen can bind to heme in hemoglobin. Mutations in this will change oxygen binding
Peptide chain
*there are 4 peptide chains of hb [ porphyrin ring ]
In the stomach the acidic environment favors the ____ form of iron, and that form will move into the intestine in this form
Ferric (3+)
Therefore moves into the intestine in the ferric state
*but enter the enterocyte in ferrous state
T/F
Heme iron is removed from the heme by enzymatic degradation
True
Iron def = ___ anemia
B12/folate def = ____ anemia
Microcytic
Macrocytic
What stimulates EPO production in the kidneys?
- Anemia
- Low renal blood flow
- Central hypoxia
What is the oxygen carrying capacity of hemoglobin
1.34mL O2 / g of Hb
Total amount of oxygen that can be carried in our blood by heme assuming every available heme has oxygen bound to it
Oxygen capacity
What is the oxygen capacity equation
- 34 x ___ hb/dL blood =
* given value
The amount of oxygen that is actually being carried in our blood
Oxygen content
% of available here’s with oxygen bound
% saturation
*determined by oxygen availability
What is the oxygen content equation?
Oxygen capacity x %saturation = oxygen content
*will get O2 capacity from previous equation where you multipled by 1.34 and you willl be given %saturation
What does RBC use ATP for?
- Flexibility of membrane
- ATPase (ion transport)
- Maintain Fe3+ state (not Fe2+)
- Prevent oxidation of hemoglobin
What happens to the RCB remnants when RBC under hemolysis ?
Phagocytosis:
- in spleen
- macrophages
- Hb recycled (made to bilirubin and recycled)
Decreased RBC or Hb causes
- Decreased O2 capacity/content
- Decreased O2 delivery
- Increased heart work load (too compensate)
Anemia
Iron overload from inadequate hepcidin (genetic mutation) causes:
1. Cardiomyopathy
Hemochromatosis
*normal O2 capacity/content and hemoglobin
does oxygen saturation decrease in hemochromatosis or anemia
No, it in unchanged
When iron is low transferrin is _____
High
Too many RBC’s is called
Polycythemia
What are the effects of polycythemia
- increased O2 capacity/content
- THICK BLOOD (increased viscosity)
- heart has to work harder
What is secondary polycythemia ? (Physiological polycythemia)
[too many RBCs]
- normal bone marrow
- heart or lung problem
What is primary polycythemia?
[too many RBC’s]
*abnormal bone marrow
(Making to much RBC)
*thrombopoietin mutation
What is physiological polycythemia?
[too may RBC]
- normal bone marrow
- body is responding to low oxygen levels (maybe from altitude)
T/F
Hemoglobin Oxygen saturation will not change even if the oxygen availability changes a lot
True
Seen by Hb-O2 curve of
What does a left shift in the Hb-O2 curve mean? Right shift ? What are they caused by
LEFT
- increased hemoglobin affinity for O2
- low CO2
- High Ph
- decreased temp
RIGHT
- decreased affinity for O2 (binds less)
- high CO2
- low Ph
- high temp
- increased 2,3 DPG (metabolites)
- IMPORTANT FOR EXCERCISE SO HB CAN LET GO OF O2 AND IT CAN GO TO THE TISSUES WHERE ITS NEEDED
What is caused by large amounts of met-hemoglobin in the body?
(Hemoglobin with Fe3+ not Fe2+)
Methemoglobinemia
- left shift in the curve
- blood is chocolate colored
- cyanosis occurs
*hemoglobin does not want to let go of this oxygen because of the iron state
