Thyroid Module Flashcards
name the 2 types of cells in the thyroid?
parafollicular (C) cells
follicular cells
what kind of tissue do parafollicular cells exist in?
connective tissue
where are parafollicular cells in relation to follicular?
adjacent to them
what substance do follicular cells make?
thyroglobulin
what substance do parafollicular cells make?
calcitonin
T or F:
the majority of all secreted hormones is triiodothyronine?
false
what organ(s) convert T4 to T3?
liver
kidneys
thyroid hormones have a role in: increasing protein synthesis increasing glucose plasma levels increasing insulin plasma levels increasing fatty acid plasma levels thermogenesis bone turnover immunity gut motility
T or F?
T T F T T F T
what action does GH have on the liver and what is the result of this?
increased gluconeogenesis =
increased plasma glucose
what action does GH have on fat tissue and what is the result of this?
increased lipolysis =
increased plasma fatty acids
what action does GH have on muscle and what is the effect of this?
protein synthesis=
decreased plasma amino acids
T or F:
thyroid hormones decrease protein synthesis
false
T or F:
thyroid hormones increase glucose and fatty acids
true
T or F:
thyroid hormones decrease fat storage
true
why do thyroid hormones increase cardiac activity and CO?
they increase responsiveness to neurotransmitters eg adrenaline and NA
what is hyperkinesis?
excessive body movement
what is oligomenorrhoea?
irregular periods
who is most commonly affected by graves disease?
middle aged women
what is the autoantibody involved in graves?
thyroid stimulating immunoglobulin (TSI)
what happens in graves?
TSI makes the thyroid gland keep releasing thyroid hormone and it cant be suppressed as it is stopping TSH from being released
normal T3 values?
9.9-22
normal fT4 values?
0.9-2.6
what is exopthalamus?
water build up and retro orbital swelling of the eye
why are the eyes particularly affected in graves?
there are lots of receptors in the tissue and muscle surrounding the eyeball stimulated by TSI
how often after diagnosis of graves is exopthalamus usually discovered?
1-2yrs
when can exopthalamus lead to loss of function?
if collagen fibres deposit in the eye
symptoms of exopthalamus?
difficulty moving eye gritty eyes blurred vision decreased colour vision redness of the eyes
how long after diagnosis of graves can you get pretibial myxoedema?
1-2yrs
what co-morbidity do patients usually have before they present with pretibial myxoedema?
graves eye disease
what is the pathology of pretibial myxoedema?
plaque formation?
is pretibial myxoedema often unilateral or bilateral?
bilateral
is pretibial myxoedema pitting?
no
what could be causing chest pain in patients with thyroid problems?
development of angina
2nd most common cause of hyperthyroidism?
toxic multinodular goitre
is hyperthyroidism more common in iodine rich or deficient areas/
deficient
what type of hyperthyroidism is hardest to treat?
when its caused by cancer
what are the additional symptoms found in de quervains thyroiditis?
fever
malaise
local tenderness
why can low iodine cause hypothyroidism?
thyroid cant synthesise MIT or DIT so it cant release thyroid hormones
why do you get a goitre in iodine deficient hypothyroidism?
TSH stimulation
thyroid enlargement
what substance is attacked by antibodies in autoimmune thyroiditis?
TPO aka thyroid peroxidase
what condition would increased TSH and normal T4 indicate?
treated hypothyroidism
what condition would decreased TSH, T4 and T3 indicate?
pituitary disease
what condition would decreased TSH with normal T4 and T3 indicate?
subclinical hyperthyroidism
how are carbimazole and PTU given?
high dose initially and then gradiually reduced over 12-18 months
main side effect of carbimazole?
agranulocytosis
symptoms of agranulocytosis?
dry cough
sore throat
