Midterm 3 Flashcards
What is the average blood volume of males and females?
Women - 5.0L
Men - 5.5L
What are the three main roles of blood?
Transportation - nutrients, hormones, waste
Regulation - Body temp., electrolytes, blood sugar
Protection - antibodies, WBCs, clotting factors
What shape is a RBC?
Biconcave discs
How much of the blood is plasma? (%)
55-58%
How much of the blood is Erythrocytes (RBCs)? (%)
42-45%
How much of the blood is the buffy coat (WBCs & platelets)? (%)
Less than 1%
What are normal hematocrit levels in males and females?
Men = 42-52
Women = 37-47
what is the main characteristic of low hematocrit?
Lower oxygen carrying capacity
How many RBCs are the per cubic mm of blood?
~ 5 million
What is the main benefit of the biconcave shape of the RBC?
- Favors diffusions of CO2 and O2
Why do RBCs have a short lifespan?
They have no nucleus or mitochondria
What is spectrin and what does it do?
- A fibrous protein found in the cytosol
- Gives shape and flexibility of RBCs
What do glycolytic enzymes do and why are they important for RBCs?
Enzymes that rely on anaerobic glycolysis to create ATP
Important that is the only way for RBCs to create ATP (RBCs contribute to blood lactate b/c of this)
What is carbonic anhydrase and what does it do?
An enzyme that allows the conversion of
CO2 + H2O <–> H2CO3 (carbonic acid) <–> H + HCO3 (bicarbonate)
this occurs when CO2 binds to hemoglobin
How long is the lifespan of an RBC?
~ 120 days or 3-4 months
Why can’t RBCs repair, duplicate, or grow?
They do not have a nucleus and therefore do not have the genetic code (DNA) to do any of these things.
In a healthy person, how much O2 is in each liter of blood?
~200mL / L of blood
How much (%) oxygen is carried in the plasma vs. bound to hemoglobin?
Plasma = ~1.5%
Bound to Hb = ~98.5%
How many oxygen molecules can one hemoglobin carry?
4 oxygen / Hb molecule
What is hemoglobin important for?
Carrying CO2 and O2, buffering H+ ions
How many subunits does a hemoglobin molecule have? and what are they called?
4 total subunits - 2 alpha and 2 beta
Where is the heme molecule in a hemoglobin and what is inside it?
In the centre of the hemoglobin, inside is iron
What molecules can hemoglobin carry? and what molecule has the highest affinity?
O2, CO2, H+, CO (carbon monoxide)
carbon monoxide has the highest affinity
How much hemoglobin is in healthy blood?
15g/100mL
What is the law of mass action and how does it apply to hemoglobin?
it means that the first oxygen is the hardest to bind to the hemoglobin but once the first one binds the rest happen very quickly.
What does saturation of hemoglobin measure?
How much oxygen is bound to hemoglobin
(100% = all subunits carry oxygen)
What does the hemoglobin-oxygen dissociation curve show?
Shows the difference in hemoglobin saturation from when the blood leaves the lungs (almost fully saturated) to when it returns to the heart. (less saturated due to oxygen offloading to the tissues)
In normal functioning, how saturated is hemoglobin when it returns to the heart?
~75%
What does a rightward shift in the hemoglobin-oxygen curve mean? and what can cause it?
Decreased Hb affinity for O2
- harder to load O2 but easier to offload
causes:
- increased temperature due to metabolically active tissues
- decreased ph
what does a leftward shift in the hemoglobin-oxygen curve mean? and what can cause it?
Increased Hb affinity for O2
- Easier to load but harder to offload O2
causes:
- increased ph (more H+ = more likely to bind to Hb)
What affect does CO2 have on hemoglobin?
when bound to Hb, Hb has a lower affinity for O2 -> increasing offloading of O2 in the tissues
(more CO2 -> more effect)
What are the three types of hemoglobin?
Type A - adult Hb (2 alpha & 2 beta subunits)
Type F - fetal Hb (has alpha and gamma subunits) (has higher affinity to allow O2 transfer from mother to fetus)
Type S - sickle cell Hb (causes anemia)
Where are RBCs made and what is the process called?
in the bone marrow of long bones
erythropoiesis
what are the cells called that all blood cells differentiate from?
hematopoietic stem cells
what stimulates erythropoiesis and how is it made?
erythropoietin is generated in the kidneys if blood oxygen in the kidneys is low
what is anemia and what is it characterized by?
abnormally low O2 carrying capacity of the blood
- reduced RBC count
- reduced Hb in blood
What values make you considered anemic?
if Hb < 12g/100mL
- or -
if hematocrit <37%