16-2: Erthyrocytes Flashcards
Erythrocytes are ___ discs packed with a red, ___-containing protein called ____.
tiny biconcave discs; iron-containing protein called hemoglobin
RBCs lose ___ when they mature.
their nucleus and most organelles
RBCs have a __ lifespan of about ____; old RBCs are removed from circulation by: ____.
short; 3-4 months; old RBCs are removed from circulation by macrophages in the liver, spleen or bone marrow. One breakdown product is bilirubin
What is responsible for the various blood types?
proteins on the surface of RBCs
Hematopoiesis
formation of blood in the red bone marrow
erythropoiesis
formation of RBCs in the red bone marrow
All blood cells arise from a stem cell called ____; RBC production begins when it becomes a ____.
hemocytoblast; proerythroblast
As the RBC proceeds through the __ and ___ stages, ___ accumulates and the ___ is ejected.
erythroblast and normoblast; hemoglobin; nucleus
The ___ stage is released into the blood, and becomes mature within 2 days.
reticulocyte
The rate of RBC formation is measured through a ___.
reticulocyte count (normal: 1-2%)
What is the stimulus for RBC formation?
erythropoietin, a hormone produced by the kidneys during hypoxia in the blood, which stimulates the red bone marrow
What is the function of RBCs?
transport of gasses
Hemoglobin combines easily with O2 in the lungs to form ____; in the tissues, O2 is released from Hb and diffuses into the ___.
oxyhemoglobin; interstitial fluid and then into the cells
Each Hb molecule binds to ___ molecules.
4 O2
Some CO2 is picked up by Hb in the ___ to form ____; in the lungs, ____.
tissues; carbaminohemoglobin; CO2 is released and exhaled
