Blood And Haemopoeisis Flashcards
What happens in differentiation in haemopoiesis?
A haemopoietic progenitor will first differentiate to form either a myeloid blast or a lymphoid blast.
What happens in proliferation in haemopoiesis?
A stem cell divides into two, one to replace the original stem cell (self renewal) and the other that differentiates
What influences what the progenitor will differentiate into? Give an example
A cytokine.
Eg erythropoietin will produce red blood cells
Thrombopoietin will produce platelets.
What will a myeloid blast go onto form?
A red blood cell, white blood cell or platelets.
What will a lymphoid blast go onto form?
Immunoresponse cells
Name the five types of white blood cells
Neutrophil Eosinophil Lymphocyte Monocyte Basophil
What is the function of neutrophils?
They migrate out of bloodstream to the site of infection (chemotaxis)
Phagocytosis
Increase the production of G-CSF
What do eosinophils do?
Phagocytosis of antigen-antibody complexes
Release cytotoxic enzymes to damage larger particles
Mediate hypersensitivity reactions - asthma, skin inflammation
What do basophils do?
Mediate acute inflammatory responses using heparin, histamine and serotonin
What do monocytes do?
Migrate to become macrophages in many organs of the body
Capable of phagocytosis and interact with T cells
Which type of white blood cell has a multi-lobed nucleus?
Neutrophil
How is erythropoiesis regulated?
Reduced pO2 detected in kidney
Stimulates production of erythropoeitin
This stimulates maturation and release of RBCs from bone marrow
Haemoglobin rises
What do lymphocytes do?
Those with CD4 on their surface - helper cells
Recognise antigens and stimulate T suppressor cells
Allow transformation of plasma cells to B cells
Those with CD8 - T suppressor cells
Recognise and kill virally infected cells.
B lymphocytes responsible for humoral immunity
Stimulated by antigens to transform into immunoblasts and then plasma cells, which secrete immunoglobulin
What do eosinophils look like?
Orange granules
Bi-lobed nucleus
What do basophils look like?
Have many dark purple granules
What do lymphocytes look like?
Small
Round nucleus
Pale rim of cytoplasm
What is the structure of an erythrocyte?
Bi concave disc
4 globulin chains (2 alpha, 2 beta)
Each molecule carries a haem
What is the function of an erythrocyte?
Carry oxygen to tissues and carry carbon dioxide to the lungs
What are reticulocytes?
Newly formed red blood cells which have only just been discharged into the blood from bone marrow
What are platelets produced by?
Megakaryocytes in the bone marrow
What does the cytoplasm of platelets contain?
Alpha granules - fibrinogen and von Willbrand’s clotting facto
Dense granules - ADP and calcium
What is on a platelet’s phospholipid surface?
Binding sites for clotting factors during activation of the clotting cascade.
