Thyroid Flashcards
the hypothalamus secretes TRH which stimulates the ___ pituitary to secrete ____. This then acts on the thyroid gland to increase production of T4 (___) and T3 (___), the two main thyroid hormones.
anterior
TSH
thyroxine
triiodothyronine
what is the difference between 1) primary 2) secondary 3) congenital hypothyroidism?
1) problem in the thyroid gland
2) usually a problem in the pituitary gland/ lesion compressing pituitary gland
3) problem of thyroid dysgenesis or dyshormonogenesis
most cases of thyrotoxicosis are PRIMARY/ SECONDARY/ CONGENITAL
primary
congenital doesn’t exist, secondary <1%
commonest cause of hypothyroidism in developed world?
Hashimoto’s
commonest cause of thyrotoxicosis?
Grave’s
name the cause of hypothyroidism
1) commonest cause in developed world
2) associated with a painful goitre and raised ESR
3) fibrous tissue replaces the normal thyroid parenchyma > painless goitre
4) drug causes?
5) most common cause in developing world
1) hashimoto’s
2) subacute thyoiditis (sub>suboptimal>hypothyroid)
3) riedel thyroiditis
4) lithium, amiodarone
5) iodine deficiency
does postpartum thyroiditis cause hypo- or hyper- thyroidism?
initial brief hyperthyroid phase followed by longed hypothyroid phase
name 2 causes of hyperthyroidism other than Grave’s
Toxic multinodular goitre (autonomously functioning thyoid nodules secrete excess thyroid hormones)
Drugs (amiodarone)
symptoms of hypothyroidism
1) general
2) skin
3) GI
4) Gynae
5) neuro
1) tired, weight gain, cold intolerance
2) dry, cold, yellowish. Non-pitting oedema (hands, face), Dry course scalp hair, loss of lateral aspect of eyebrows
3) constipation
4) menorrhagia
5) decreased deep tendon reflexes, carpal tunnel
symptoms of hyperthyroidism
1) general
2) cardiac
3) skin
4) GI
5) Gynae
6) neuro
1) weight loss, ‘manic’, restless, heat intolerance
2) palpitations, arrhythmia
3) sweating, pretibial mxyoedema, thyroid acropachy (clubbing)
4) diarrhoea
5) oligomenorrhoea
6) tremor, anxiety
TFTs primarily look at levels of ___ and __
T4 and TSH
T3 can also be measured but is only useful clinically in a small number of cases
what is more sensitive for monitoring patients with thyroid problems -TSH or T4 levels?
TSH
- often used to guide treatment
Interpret:
1) low TSH, high T4
2) high TSH, low T4
3) low TSH, low T4
4) high TSH, normal T4
1) thyrotoxicosis
2) primary hypothyroidism
3) secondary hypothyroidism or sick euthyroid syndrome
4) subclinical hypothyroidism or poor compliance with thyroxine
nuclear scintigraphy revealing patchy uptake suggests what underlying pathology?
toxic multinodular goitre
Treatment of thyrotoxicosis
1) ___: symptom control
2) ___: blocks thyroid peroxidase from coupling and iodinating thyroglobulin
3) radio___ treatment
1) propranolol
2) carbimazole
3) iodine
