Red cells Flashcards
What is haemopoiesis?
Production of erythrocytes, platelets, megakaryocytic and leukocytes
What substance influences the production of erythrocytes?
Erythropoietin
What are granulocytes?
Basophils, neutrophils, eoisinophils
What factors stimulate granulocyte formation?
Granulocyte cologne stimulating factors (G-CSF);
GM-CSF (Granulocyte-macrophage stimulating factor)
What factor stimulates platelet formation?
Thrombopoietin
What cells are multipotent?
Myeloid progenitor cells
Lymphoid progenitor cells
What is the function of erythrocytes?
Oxygen transport
What is the function of neutrophils?
Inflammation, phagocytosis of pathogens
What is the function of eosinophils?
Defence against parasitic infection?
What is the function of platelet?
Haemostasis
What is WBC?
White blood count, number of white blood cells in a given volume
What is RBC?
Number of red blood cells in a given volume
What is Hb?
Haemoglobin concentration
What is Pcv?
Mean packed volume proportion of centrifuged blood occupied by red cells
What is Hct?
Haematocrit, equivalent to PCV
What is MCV?
Men cell volume, the average size of red cells
What is MCH?
Mean cell haemoglobin, average amount of haemoglobin in a red cell
What is MCHC?
Mean cell haemoglobin concentration, the average concentration of haemoglobin in red cell
What is platelet count?
The number of platelets in a given volume of blood
What do myeloid progenitor cells give rise to during erythropoiesis?
Proerythroblasts –> erythroblasts –> eryhthrocytes
In respinse to cellular hypoxia , which hormone is released to stimulate erythropoeisis?
Erythropoeitin
Where is erythropoietin synthesised and released from?
Kidney
What other hormone stimulates release of erythropoietin?
Testosterone
Which cells secrete erythropoietin?
Juxtatubular cell association with the particular capillary and proximal convoluted tubule
Which factors stimulates the synthesis of erythropoietin?
Hypoxia-inudicble factors
Which receptors does erythropoeitin bind onto?
Epo receptors
What proteins carry oxygen in RBCs?
Haemoglobin
How is the prophetic haem group arranged?
Haem group is bound to ferrous group held in porphyrin ring
What are the adaptations of RBCs?
Thin cell membranes reduces diffusion pathway for oxygen molecules
No nucleus: Maximum storage capacity of Hb
Biconcave shape: Increases
SA:V ratio
What is the structure of haemoglobin?
Conjugated globular protein with quaternary structure of 2 alpha and 2 beta polypeptide chains.
Each chain is arranged around a haem group.
primary structure: Pseudo-repeating sequence of amino a
Why are haemoglobin molecules soluble?
Hydrophillic and hydrophobic interactions , polarised amino acid variable groups exposed externally, potential to form hydrogen bonds with water,
Why is Hb Susceptible too denaturation?
No covalent or disulphide bonding between chains, therefore weakly linked.