Haematopoietic system and component parts; part 2 Flashcards
What are primary lymphoid organs?
Thymus and bone marrow, this is where lymphocytes are created
What are secondary lymphoid organs?
Spleen and lymph nodes, this is where the immune response is initiated/ lymphocytes are stored
When is your thymus most active?
When you are younger (developing fetus)
What is the thymus divided into?
lobes that contain an outer cortex and medulla
What is the function of the thymus?
provides an environment for T cell development
What is the main function of the spleen?
survey the presence of foreign antigens in the blood
What are the two types of tissue found in the spleen?
Red and white Pulp
What is the function of white pulp?
looks for foreign antigens
What is the function of red pulp?
damages/ destroys Red Blood Cells
What is the name of the vessels that extracellular fluid drains into?
Lymphatics, the extracellular fluid may also contain foreign antigens/ pathogens
What are lymph nodes?
small tissue aggregates that become much larger during infection
What enters via the afferent lymphatic?
Lymph that carries antigens and DC’s
What are the 3 main areas of lymph nodes?
cortex, paracortex and medulla
Where do lymphocytes exit the lymph node?
via the efferent lymphatic
What is the germinal centre?
Area in secondary lymphoid tissue where B cells congregate
What is MALT?
a type of lymphoid tissue primarily found in the mouth (where mucosal membranes are)
What are Peyers patches?
Linings of lymphocytes found in the gut
How do lymphocytes enter the lymph nodes from the blood?
Through high endothelial venules
Through which pulp do the T cells enter?
they enter the white pulp via terminal arterioles
