Blood (B1-B3) Flashcards
(126 cards)
what are the two major components of plasma
water & solids (proteins, glucose, etc)
the chemical composition of plasma is very similar to this fluid in most tissues
interstitial fluid
these are the two extracellular fluids, one is intravascular and the other in extravascular
plasma and interstitial fluid
this is the process by which formation and development of all blood cells takes place
hematopoiesis
where does hematopoiesis take place in adult mammals
marrow of flat bones and ends of long bones
where does hematopoiesis take place in neonate and juvenile mammals
bone marrow of long bones
what 3 essential physiologic components are required for hematopoiesis
- stem cell pool
- hematopoietic inductive microenvironment
- hematopoietic cytokines
these are the hormones that regulate hematopoiesis
hematopoietic cytokines
the first step in hematopoietic differentiation involves a commitment of the stem cell to one of these two large pathways
myeloid or lymphoid
what is the earliest recognizable erythroid precursor
rubriblast
during the mitosis divisions of rubriblast to late precursors metarubricytes, what 3 things change on the progressive maturation of the nucleus and cytoplasm
- decreasing cell size
- increasing proportion of the cell occupied by cytoplasm (N:C ratio decreases)
- decreased cytoplasmic basophilia (decr in organelles, incr in hemoglobin content)
this is an immature, but non-nucleated RBC; larger than a mature RBC (higher MCV) and contain less Hb (low MCHC)
reticulocyte
this is the principle hormone regulating erythropoiesis; stimulates the increase of RBCs therefore increasing the oxygen-carrying capacity of the blood
Erythropoietin (EPO)
where is Erythropoietin (EPO) produced?
kidney (by the peritubular interstitial cells)
what are 4 major functions of Erythropoietin (EPO)
- proliferation of committed erythroid cells
- increases hemoglobin synthesis
- increases erythroid cell maturation rate
- stimulates early release of reticulocytes
what are the 3 major function of mature erythrocytes (RBCs)
- transport oxygen to tissues
- transport CO2 to lungs
- buffer hydrogen ions
how are the energy needs of RBCs met?
anaerobic glycolysis (no mitochondria)
what is the principle energy source for RBCs
glucose
the anaerobic glycolytic pathway produces a net gain of these 2 things
ATP & NADH
what is ATP used for in RBCs
to maintain osmotic stability
what is NADH used for in RBCs
in the process to keep iron molecules in a reduced state
this is a side pathway associated to anaerobic glycolysis which generates other products for erythrocyte metabolism:
produces 2,3-DPG which modulates affinity of hemoglobin for O2
DPG shunt
this is a side pathway associated to anaerobic glycolysis which generates other products for erythrocyte metabolism:
generates NADH, involved in maintenance of Fe and GSH in reduced states; GSH involved in protecting from oxidative injury
pentose phosphate pathway
the rate of iron absorption is influenced by the need for Fe in the body, and is controlled by this peptide secreted by hepatocytes
hepcidin