endocrine principles Flashcards
what are the different types of hormone receptors
G-protein coupled receptors
receptor Tyrosine kinase families (RTK)
receptors associated with tyrosine kinase activity
Steroid hormone receptors
What are the features of G protein coupled receptors?
they activate a limited number of regulatory signalling cascades (eg cAMP)
they are suited to act as biological sensors
they are the main sensors of the internal environment
many endocrine disorders are associated with defects in GPCRs
How many GPCR are there in humans?
around 750
are steroid hormone receptors extracellular or intracellular?
mainly intracellular (in the cytoplasm or nucleus)
what are some examples of nucleus receptor steroid hormones?
oestrogen and androgen receptors
what does the steroid/receptor complex bind to?
DNA response elements
what does the steroid/receptor/DNA complex lead to?
changes in gene trasncription
how is thyroid hormone measured?
highly sensitive TSH assay
what does a high TSH indicate?
Hypothyroidism
what does a low TSH mean?
hyperthyroidism
is TSH reliable in pituitary dysfunction (secondary hypothyroidism)?
NO
what secretes prolactin?
lactotroph cells of the anterior pituitary
what does cortisol deficiency indicate?
primary adrenal failure eg addisons disease
pituitary disease
what does cortisol excess indicate?
cushings syndrome
what are the features of cushings syndrome?
Cushingoid facies
Acne
Hirsutism
Abdominal striae & centripetal obesity
Interscapular & supraclavicular fat pads
Proximal myopathy
Osteoporosis
Hypertension
Impaired glucose tolerance
