Immunology of the endocrine system Flashcards
What gender is most autoimmune conditions more common in
Females
What are tolerogens
Antigens that induce tolerance
What is immunological tolerance
Unresponsiveness to an antigen that is induced by previous exposure to that antigen
What is self-tolerance
The bodies tolerance to self antigens
What is an autoimmune disease
Failure of self tolerance
What happens to B and T lymphocytes that have a high affinity receptor for self antigens
They are killed because the body does not want an autoimmune confition
What cells maintain peripheral tolerance and how do they do it
Tregs - T regulatory cells that suppress the activation of lymphocytes which are specific for self-antigens
What can cause peripheral tolerance to be overcome
Injury or another event that leads T cells finding the self-antigens
Increased expression of co-stimulatory molecules
Changes in the way the self molecules present to the immune system
What is the function of HLA - human leukocyte antigens
codes for proteins that help differentiate between self and non-self
What can cause autoimmune diseases
Environmental factors
infection
drugs
UV radiation
How do infections and drugs cause autoimmune disease
Molecular mimicry - makes proteins that looks like self proteins which might make the autoimmune attack the self antigens
What is the treatment plan of autoimmune diseases
Supress the damaging immune response and replace the functions of the damaged organ
What does beta islet of langerhan secrete
insulin
What does alpha islets of langerhan secrete
glucagon
What does delta islets of langerhan secrete
somatostatin
Describe type one diabetes
Inadequate insulin secretion due to destruction of beta cells
Can cause ketoacidosis
Describe type 2 diabetes
More common
Normal or increased insulin secretion
Reduced number of cell surface receptors for insulin
What genetic factors is type one diabetes associated with
Certain HLA types - human leukocyte antigen - helps differentiate between self and non self
What are the complications of diabetes
Large blood vessels - accelerated thrombosis and associated complications - myocardial infarction
Small blood vessels - endothelial and basal lamina damage e.g retinopathy and nephropathy
Describe the thyroid gland
Follicle cells lined by cuboidal cells which contain colloid in them - thyroid gland synthesises T3 and T4
C-cells of the thyroid gland secrete calcitonin
What is the most common cause of hyperthyroidism
Grave’s disease
How does Grave’s disease work
Has autoantibody IgG and long acting thyroid stimulator (LATS) which bind to the thyroid epithelial cells and mimic TSH
What are common signs seen in graves thyroiditis
Exophthalmos, pretibial myxoedema and clubbing
What is the most common cause of hypothyroidism
Hashimotos thyroiditis