Monday, 29 June 2020 5:31 PM
LEARNING OUTCOMES
ANATOMY & PHYSIOLOGY
Demonstrate an understanding of the main elements of blood and their function:
• Difference between plasma and serum;
○ Plasma: Exerts osmotic effect that is important for distribution of ECF betw
interstitial components, makes up 55% of blood
§ Albumins: Non-specifically binds to many poorly soluble substances
osmotic pressure to maintain water balance
§ Globulins: Alpha + beta - Transports proteins that bind to lipids, ions
vitamins
§ Fibrinogen: Inactive precursor for the fibrin meshwork of clotting
○ Serum: Similar to plasma but doesn’t include clotting factors such as fibrin
coagulation
• Red blood cells (RBC)(erythrocytes) – type of progenitor cell they originate from
destroyed, life span, morphology and how this links to function;
○ Erythropoiesis: Haemocytoblast in bone marrow can differentiate into my
becomes proerythroblast (committed to becoming RBC) → Differentiates t
erythroblast → Polychromatic erythroblast → Orthochromatic erythroblast
Reticulocyte formed (nucleus + organelles ejected) → Excreted through s
Matures into RBC into blood → Migrates to spleen where dense capillary
to rupture → Macrophages phagocytose RBC → Fragments and compone
further use.
§ Requirements for erythropoiesis: Iron and amino acids for Hb synthe
Vitamin B12 assists with DNA synthesis and cell division; Vitamin C a
cofactors that assist with release and transfer of iron for Hb synthesi
○ Life span: Approx. 120 days
○ Structure:
§ Thin - short distance for diffusion of substances
§ Biconcave - Large SA for diffusion
§ Flexible membrane - Ability to deform to pass through capillaries
§ Lack of nucleus and organelles - Maximises haemoglobin content an
capacity
○ Function:
§ Transports oxygen to tissues and carries carbon dioxide as a waste
via expiration
• Regulation of RBC production by erythropoietin (EPO), including site of EPO pr
EPO acts to stimulate RBC production.
○ Hypoxia induces the stimulation of the erythropoietin activating gene → H
increasing synthesis of erythropoietin in renal cells → binds to receptors in
stimulate erythropoiesis.