Structure, Function and Production of
RBC
Erythrocyte - ANS A mature red blood cell.
-contains the oxygen‐carrying protein hemoglobin, which is a pigment that gives
whole blood its red color.
hemoglobin - ANS A substance in red blood cells consisting of the protein globin
and the iron‐containing red pigment heme that transports most of the oxygen
and some carbon dioxide in blood.
To maintain normal numbers of RBCs, new mature cells must: - ANS enter the
circulation at the astonishing rate of at least 2 million per second, a pace that
balances the equally high rate of RBC destruction.
RBC Anatomy - ANS -biconcave discs with a diameter of 7-8 μm. (1 μm = 1/25,000
of an inch)
-Mature red blood cells have a simple structure.
RBC plasma membrane - ANS -strong and flexible and can deform without
rupturing as they squeeze through narrow capillaries.
-certain glycolipids in the plasma membrane of RBCs are antigens that account
for the various blood groups such as the ABO and Rh groups.
RBC nucleus - ANS -lack a nucleus and other organelles and can neither
reproduce nor carry on extensive metabolic activities.
RBC cytosol - ANS -contains hemoglobin molecules; these important molecules
are synthesized before loss of the nucleus during RBC production and constitute
about 33% of the cell's weight.
RBC Physiology - ANS -highly specialized for their oxygen transport function.
-all internal space is available for oxygen transport.
, -lack mitochondria and generate ATP anaerobically (without oxygen), they do not
use up any of the oxygen they transport.
-the shape of an RBC facilitates its function. A biconcave disc has a much greater
surface area for the diffusion of gas molecules into and out of the RBC.
Hemoglobin - ANS -consists of a protein called globin, composed of four
polypeptide chains (two alpha and two beta chains)
-Each RBC contains about 280 million hemoglobin molecules.
-transports about 23% of the total carbon dioxide, a waste product of metabolism.
hemoglobin and carbon dioxide: - ANS -Blood flowing through tissue capillaries
picks up carbon dioxide, some of which combines with amino acids in the globin
part of hemoglobin. As blood flows through the lungs, the carbon dioxide is
released from hemoglobin and then exhaled.
heme - ANS -a ringlike non protein pigment that is bound to each of the four
chains.
-At the center of each heme ring is an iron that can combine reversibly with one
oxygen molecule, allowing each hemoglobin molecule to bind four oxygen
molecules.
oxygen molecule picked up from the lungs________________________ - ANS
-Each oxygen molecule picked up from the lungs is bound to an iron.
-As blood flows through tissue capillaries, the iron-oxygen reaction reverses.
-Hemoglobin releases oxygen, which diffuses first into the interstitial fluid and
then into cells.
How many molecules can one hemoglobin molecule transport? - ANS One
hemoglobin molecule can transport a maximum of four molecules, one bound to
each heme group.
hemoglobin and blood flow and blood pressure - ANS -The gaseous hormone
nitric oxide (NO), produced by the endothelial cells that line blood vessels, binds
to hemoglobin.
-Under some circumstances, hemoglobin releases NO.
-The released NO causes vasodilation, an increase in blood vessel diameter that
occurs when the smooth muscle in the vessel wall relaxes.
-Vasodilation improves blood flow and enhances oxygen delivery to cells near the
site of NO release.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LECTFELICITY. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.99. You're not tied to anything after your purchase.
