Red Blood Cell Production

What components make up blood?

• red blood cells

• white blood cells

  • monocytes

  • neutrophils

  • eosinophils

  • basophils

  • lymphocytes

• platelets

At 5 years old where does RBC formation occur?

• bone marrow in all bones

Between 5-20 years old where does RBC formation occur?

• in the bone marrow of the long bones

  • femur and tibia

At 20+ years where does RBC formation occur?

• in the bone marrow of membranous bones

  • vertebrae, sternum, ribs, and pelvis

What are the stages of mature RBC formation?

What plasma proteins are part of blood composition?

• albumins (60%)

  • maintains blood volume and transports

• globulins (35%)

  • transports and has immune functions

• fibrinogen (4%)

  • component of clotting system

• regulatory proteins (1%)

  • enzymes, proenzymes and hormones

What are albumins in charge of?

• controls osmotic pressure in plasma

• transports fatty acids and thyroid hormones

• moves bilirubin

What are globulins responsible for?

• transport small molecules

• serve an immune function

Do RBCs proliferate?

Can RBCs repair themselves?

• no

• no

How long is a RBC lifecycle?

How do RBCs get ‘killed’?

• 120 days

• 90% are engulfed by phagocytes and 10% rupture

What happens to haem group from dead RBC?

• phagocyte recognises it so it can be recycled

What charge is membrane of RBC?

• negative surface charge due to glycoprotein coat

What is the membrane of RBC made of?

• lipid bilayer

• outer glycoprotein coat (gives the negative surface charge)

What are RBCs stained with and what does this cause?

• stained with eosin which causes the RBC to go red colour (more pigmented around perimeter)

What are the stages of mature RBC formation?

Proerythroblast

•  first erythrocyte precursor, differentiates from multipotent stem cell due to influence from erythropoietin

Basophilic erythroblast

• Smaller than proerythroblast has more ribosomes in cytoplasm though, involved in production of haemoglobin

Polychromatophilic erythroblast

• Last precursor cell capable of mitosis, smaller than basophilic erythroblast

Normoblast

• Contains a nucleus

Reticulocyte

• Still has a slight basophil stain

Erythrocyte

• Final product of erythropoiesis and is released from the bone marrow into circulation

What does erythropoietin do?

• stimulates proliferation and differentiation of precursor stem cells to produce mature RBCs

What causes blood to agglutinate/ coagulate?

• if the blood type has antibodies for the other blood type/ blood antigen, then the antibodies “kill” it by agglutinating

  • e.g. B+ would agglutinate with anti-A making it useless (dead)