Lymphoid Tissue Flashcards
The innate immune system retains the phagocytic system in the form of what?
Monocytes/macrophages and neutrophils
How can you find primary lymphoid organs?
Sites of lymphocyte production and maturation (bone marrow and thymus)
How can you find secondary lymphoid organs?
Sites to which lymphocytes migrate and aggregate in large numbers (spleen, lymph nodes and lymph nodules)
What are the three forms of lymphocytes?
B Lymphocytes, T Lymphocytes and Natural killer cells
What are distinctive whorls of epithelial cells called?
Hassall’s corpuscles
The system of lymphatic vessels and lymph nodes provide?
Drainage of lymph into the vascular system.
Surveillance of tissue for signs of antigens from foreign invaders, such as bacteria
Delivery of absorbed fats from the small intestine into the vascular system via lymphatic vessels in the villi of the small intestine
What centre does a secondary follicle have?
Germinal centre
What does the medulla of the lymph node contain?
Medullary cords and medullary sinuses
Where do B cells mature into plasma cells?
Medulla
What are the functions of the spleen?
Produce immune response against blood borne antigens
Removal of participate matter and aged blood cells
Production of blood cells during foetal life
What is the white pulp made up of?
T cells and B cells
What is the red pulp made of?
Blood filled capillaries
What is the main role of adaptive immunity?
Destruction
What are barriers against invasion?
Skin
Mucosa
Stomach acid
Antibacterial agents
What are phagocytes?
Macrophages and neutrophils
What is the adaptive immunity based on?
Lymphocytes and cell surface receptors
What must lymphocytes not react to in adaptive immunity?
Self antigens
What are examples of autoimmune diseases?
Rheumatoid Arthritis Addison’s disease Multiple sclerosis Hashimoto disease Graves’ disease Myasthenia gravis
What is the tissue attacked in Rheumatoid Arthritis?
Synovial joints
What is the tissue attacked in Addison’s disease?
Adrenal cortex
What is the tissue attacked in Multiple sclerosis?
CNS myelin
What is the tissue attacked in Hashimoto’s disease?
Thyroid gland
What is the tissue attacked in Graves’ disease?
Thyroid gland
What is the tissue attacked in Myasthenia Gravis?
Neuromuscular junction
What do B cells produce?
Antibodies
What do T cells participate in?
Cellular immunity
What is each lobe of the thymus subdivided by?
Septa of reticular fibres
What do immature T cells leave?
Blood vessels
Where do immature T cells enter?
Cortex of thymus
What happens to failed T cells?
Undergo apoptosis and phagocytosis by macrophages
What happens to the T cells that survive?
Enter the medulla and interact with epithelial cells
Where are Hassalls corpuscles?
Medulla of thymus
Where are lymph nodes found?
Neck, axillae and groin
Lymphoid follicles can be?
Primary or secondary
Paracortical region is populated with what?
T cells
An example of MALT?
Waldeyer’ ring
Examples of extracellular killers?
Lymphocytes and eosinophils
What must the immune system have the ability to do?
Distinguish from self and non-self
What happens when the immune system fails to distinguish between self and non-self?
An autoimmune disease occurs
What are the three forms of T-cells?
Helper T cells, cytotoxic T cells and suppressor T cells
Function of natural killer cells?
Kill virus infected cells and some tumour cells
How are cells of the immune system identified?
Using immunohistochemistry
What subdivides the thymus?
Septa
What part of the thymus are immature T cells found?
Cortex
What do Hassall’s corpuscles contain?
Keratin
What are the circular aggregations with the lymph node known as and what do they contain?
Follicles and B cells
What are the densely pack follicles of the lymph node called?
Primary follicle
What surrounds the germinal centre of the lymph follicle?
Mantle zone
What is with the mantle zone?
Resting B cells
