Lecture 1 - Introduction to disorders of the endocrine system - Pituitary and Thyroid Flashcards
Define hypo-secretion and give an example of a condition
Not enough secretion of the hormone
Problems with the endocrine gland
e.g. type 1 diabetes
Define hyper-secretion and give and example of a condition
Too much hormone is being secreted
Not cancerous a benign tumour - proliferation and overgrowth of the gland more hormone-producing material therefore you get more hormone secreted
e.g. pancreatic endocrine tumour
Define hypo-responsive and give and example of a condition
e.g. insulin resistant type 2 diabetes
Insulin receptors can’t signal effectively even though there is enough insulin in the body
Define hyper-responsive and give an example of a condition
TSH receptor constitutive activation - hyperthyroidism
Inappropriate activation of those hormones which leads to excess production of thyroid hormone
Define acromegaly
Caused by excessive production of growth hormone
common in Middle Ages
can result in premature death
slow onset
bony features tend to be overgrown
symptoms:
abnormal growth of hands and feet
What does excessive growth hormone cause?
Hypersecretion
Gigantism - early life pituitary tumour - not cancerous
Acromegaly - pituitary tumour adolescence (after adolescence)
What do growth hormone deficit cause?
Dwarfism:
- general anterior pituitary dysfunction
- specific GH deficit
- normal GH hereditary somatomedin deficit
Accelerated ageing - loss of growth hormone after adolescence - decreased protein synthesis
Explain the treatment of acromegaly
Surgical removal of tumour
drug therapy
Octreotide and Lanreotide - can switch off GH production
Pegvisomant - GH receptor antagonist
Bromocriptine - dopamine agonist
Radiation therapy - selectively targets the overgrowth
What is prolactinoma?
Hyperprolactinemia
Bengin tumours
Overproduction of the milk hormone
Symptoms of prolactinoma
Galactorrhoea - leaky breasts
Amenorrhoea - females absence of periods
Hypogondism- diminished production of sex hormones
Erectile dysfunction
Vision loss
Treatment for prolactinoma
Prolactin inhibiting factor (PIF) is dopamine
Dopamine acts at D2 receptors in the pituitary gland to inhibit prolactin release
Cabergoline and bromocriptine are dopamine agonists that inhibit prolactin production and can reduce the size of a prolactinoma
What drug could promote excess production of prolactin ?
Antipsychotics that are D2 receptor antagonists can cause hyperprolactinaemia because blocking the inhibition can lead to excess prolactin
Define hypopituitarism
Results from a deficiency in one or more pituitary hormones - potentially very serious means your adrenal, pituitary and sex hormones are not regulated
Define panhypopituitarism
A deficiency in all anterior pituitary hormones
Causes of hypopituitarism
Traumatic, infective, vascular, autoimmune functional
