1: Physiology of blood cells Flashcards
Describe how all blood cell types are formed
Multipotent haemopoietic stem cells
-> Lymphoid/myeloid stem cells
What can lymphoid stem cells produce?
T cell
B cell
NK cell
What can myeloid stem cells produce?
Erythroid
Megakaryocyte
Granulocyte
Monocyte
What is the function of stem cells?
Produce mature progeny and also self-renewing
What is the name of the process of erythrocyte production? Describe the steps
Erythropoiesis
Myeloid stem cell -> proerythroblast -> erythroblast -> erythrocyte
What substance is required for erythropoiesis? Where is it produced
Erythropoietin
90% from Juxtatubular Interstitial cells (KIDNEY)
10% from Liver
How long do RBCs last in the blood
120 days
What is the function of red blood cells and how is it destroyed
Transport O2 and some CO2
Destroyed by phagocytic cells in SPLEEN
What are myeloblasts and what can they produce?
Come from multipotent haemopoietic stem cells
Produce granulocytes and monocytes (neutrophils)
Cytokines needed for this
How long do neutrophils stay in blood?
7-10 hours before migrating into tissues
Describe the physiology of neutrophils
Derived from myeloblasts
Stays in blood 7-10 hours before migrating into tissues
Phagocytosis
Kills micro-organisms
How do neutrophils get out of the capillary?
Adhesion + rolling
Describe the physiology of eosinophils
Granulocytes derived from myeloblasts
Stays in blood shorter than neutrophils
Defense against parasitic infection
Describe the physiology of basophils
Granulocytes derived from myeloblasts
Involved in allergic responses
Describe the physiology of monocytes
Myeloid stem cell -> monocyte precursor -> monocyte
Stays several days in circulation
Migrate to tissues -> develop into macrophages and other cells with phagocytic function
Macrophages also store/release iron
Describe the physiology of platelets
Derived from megakaryocytes
Stays 10 days in blood
Primary haemostasis
Contributes phospholipid, promotes blood coagulation
Describe the physiology of lymphocytes
Derived from lymphoid stem cell
Recirculate to lymph nodes/other tissues then back to blood stream
Variable life span
What is anisocytosis/poikilocytosis
anisocytosis = Red cells show more variation in SIZE than normal poikilocytosis = Red cells show more variation in SHAPE than normal
What is micro/macrocytosis
Microcytosis = red cells SMALLER than normal (microcytes) Macrocytosis = red cells LARGER than normal (macrocytes)
Why is the centre of normal red cell paler?
It has less haemoglobin
What is hypochromia
Red cells have larger than normal central pallor
Due to lower haemoglobin content and flatter cell
Often goes together with microcytosis
What is hyperchromia
Red cells lack central pallor
Due to being thicker/abnormal shape
What are two important types of hyperchromia
Spherocytes = spherical, regular outline, lack central pallor, result of loss of cell membrane without loss of cytoplasm
Irregularly contracted cells = irregular outline, smaller than normal, lack central pallor, result of oxidant damage
