Endocrinology Flashcards
What hormones are released by the posterior pituitary?
Oxytocin + ADH
What are the 3 layers of the adrenal cortex and what do they produce?
zona glomerulosa, fasciculata and reticularis
What does the glomerulosa produce?
Mineralocorticoids e.g. aldosterone
What does the zona fasciculata produce?
GLucocorticoids e.g. cortisol
WHat does the zona reticularis produce?
Androgens
Where are Norepinephrine and epinephrine produced?
renal medulla
What does TRH act on
the anterior pituitary causing it to release TSH
What does TSH act on?
the thyroid, causing it to release T3 and T4 (thyroxine)
What does T4 inhibit?
THe hypothalamas and anterior pituitary
What does LH act on?
Leydig cells to produce testosterone
What does FSH act on?
Sertoli cells to produce androgen binding globulin and inhibin
What hormons is under negative control from the hypothalamus?
Prolactin
Name a treatment for prolactinoma?
Cabergoline
How is cushing’s syndrome investigated?
Overnight dexamethasone suppression test
How is acromegaly diagnosed?
Glucose tolerance test
Treatment of acromegaly
Surgical removal of pituitary tumour
2 main features of Conn’s syndrome
Hypertension and hypokalaemia
Increased aldosterone production is known as
Conn’s syndrome
What does aldosterone do
absorb sodium and water, excrete potassium in the distal convoluted tubule
Blood test result in conn’s
raised aldosterone to renin ratio
Diagnosis of Conn’s
aldosterone does not decrease with an IV 0.9% saline solution in Conn’s
Name an aldosterone agonist
spironolactone
Central vs nephrogenic diabetes insipidus
Central = pituitary does not release ADH
Nephrogenic - kidney not responding to ADH
What does ADH do?
Water reabsorption in the colelcting ducts
Blood test result in diabetes insipidus
hypernatraemia
How is diabetes insipidus diagnosed
water deprivation test
treatment for central diabetes insipidus
desmopressin
Most common cause of SIADH
small cell lung cancer
Plasma concentration of salt is ____ in SIADH
Low
What causes secondary hyperparathyroidism
prolonged hypocalcaemia e.g. CKD, vitamin D deficiency
Symptoms of hyperparathyroidism
stones - calcium stones in kidney
bones - bone pain, osteopaenia, weak bones
groans - abdo pain
psychiatric overtones - depression, anxiety
Calcium is _____ in hyperparathyroidism?
Elevated
Symptoms of hypoparathyroidism?
Paraesthesia, tetany, hyperphosphataemia
2 signs that are positive in hypocalcaemia
Chvostek’s sign and trousseau’s sign
What is affected in secondary hypothyroidism?
Pituitary gland
Most common cause of hypothyroidism in UK?
Hashimoto’s thyroiditis
What is addison’s disease?
Not enough cortisol or aldosterone
Investigation for addison’s disease?
Adrenicocorticotrophic Hormone (ACTH) stimulation test
Antibodies present in Hashimotos thyroiditis (autoimmune hypothyroidism)
anti-thyroid peroxidase (TPO)
Anti-Tg antibodies
What antibodies are present in 90-100% of people with grave’s disease?
TSH receptor antibodies
What causes addison’s disease
Autoimmune destruction of the adrenal glands
Hyperpigmentation of the palmar creases indicates
Primary Addison’s disease
Most common causes of HYPERcalcaemia
malignancy
hyperparathyroidism
Management of thyrotoxicosis
carbimazole 6 weeks
Most common causes of DKA
infection
MI
missed insulin
what is Kussmaul respiration?
Deep hyperventilation seen in DKA
Blood test results in addisons
high potassium and calcium, low sodium, low glucose
Painful goitre, hypothyroidism and raised ESR poijnts to
subacute thyroiditis, de Quervain’s
Diagnosis of acromegaly?
Serum IGF-1 measurements
Karyotype in kleinfelter’s syndrome
47, XXY
what is 5-alpha reductase syndrome?
inability to convert testosterone into dihydrotestosterone
Characteristic features of Kallmann’s syndrome
lack of smell in a boy with delayed puberty
What would you see on thyroid scintigraphy in De Quervain’s? thyroiditis
globally reduced uptake of iodine-131
What is De Quervian’s?
Subacte thyroiditis - hyperthyroidism`
2nd most common cause of cushing’s after steroids?
Pituitary adenoma
Subclinical hypothyroidism on blood test…
elevated TSH with normal T4 indicates
What to give if calcium >3
IV bisphosphonates
Orphan Annie eyes on microscopy are seen in
Papillary thyroid cancer
Calcitonin is a tumour marker for
medullary thyroid cancer
thyroglobulin is a tumour marker for
papillary and follicular thryoid cancer
Raised serum parathryoid would also give…
raised serum calcium and low phosphate
Hashimoto’s thyroiditis = which antibody
anti TPO
What is the target HbA1c in type 2 diabetes?
48 mmol
What medication changes should be made in a sick patient with addison’s disease?
double the dose of glucocorticoids e.g. hydrocortisone
treatment f addisons
glucocorticoid and mineralocorticoid replacement therapy
hydrocortisone + fludrocortisone
What does radioactive iodine treat
toxic multinodular goitre
What IS addison’s disease
Autoimmunde destruction of the adrenal glands
How is addison’s disease diagnosed
Short synacthen test (it should stimulate cortisol production)
Blood test results in addisons
hyponatraemia
hyperkalaemia
Diagnosis of phaeochromocytoma?
24 hour urinary collection of mentanephrines
What may be needed in childhood for turner’s syndrome treatment
growth hormone
Name a drug that most commonly causes gynaecomastia
spironolactone
Most common cause of secondary hypothyroidism
pituitary insufficiency
TSH and T4 in SECONDARY hypothyroidism
low tsh, low t4
Treatment of diabetic ketoacidosis in adults
0.1units/kg/hour insulin IV
initial treatment of DKA
fluids THEN insulin
When should you add a 2nd drug (after metformin) in a patient not controlling their T2DM?
HbA1c > 58
How is Conn’s syndrome diagnosed?
Renin:Aldosterone ratio
Hypertension + hypokalaemia =
primary hyperaldosteronism/Conn’s syndrome
most common cause of hyperparathyroidism?
solitary parathyroid adenoma
What characterises an addisonian crisis?
hyperkalaemic metabolic acidosis
How should regular insulin be managed in acute DKA treatment?q
fixed rate insulin
continue regular long acting insulin
stop short acting insulin
treatment of addisonian crisis
hydrocortisone 100mcg im or iv
most important blood test in hashmotos
TSH
most common cause of hyperaldosteronism
bilateral adrenocortical hyperplasia
treatment of hyperalsostetonism
spironolactone
what blood test do you need to do when starting carbimazole and why
FBC - rule out agranulocytosis
lack of what electrolyte may cause hypocalcaemia?
magnesium
Klinefelter’s syndrome causes hormonally…
high LH, low testosterone
Management of hypercalcaemia
IV saline, THEN bisphosphinates
hyponatraemia and hyperkalaemia points to…
Addison’s disease
Pepper pot skull indicates…
hyperparathyroidism
Which medication controls BP in phaechromocytoma?
labetoloL
side effects of sulfonylureas
weight gain (hypos)
complication of fluid resuscitaiton in DKA
cerebral oedema
blood results in cushing’s
hypokalaemic metabolic alkalosis
treatment of Addisonian crisis
IV hydrocortison
Blood Features of an addisonian crisis
hyperkalaemia, hyponatramia, hypoglycaemia
1st line management of prolactinoma?
bromocriptine
how many readings do you need before you can diagnose diabetes in asymptomatic patients?
2
what fasting and random glucose test suggest diabetes?
fasting >7mmol/l
random >11.1mmol/l
