Pastest Notes Flashcards
What does somatostatin inhibit?
Growth hormone (GH) Also known as growth hormone-inhibiting hormone (GHIH)
Define tetany and its endocrine causes?
Muscle spasm/twitching
Caused by low PTH resulting in low serum calcium
Chvosteks sign
Facial muscle twitching when facial nerve is tapped. CHvosteks - CHeek tap
Trousseau’s sign
Hand spasm with BP cuff (stops what little serum calcium there is from passing into the hand)
TRousseu’s TRaps calcium upstream
Another name for epinephrine
adrenaline = noradrenaline
What stimulates TSH and prolactin release from pituitary and where is this hormone produced?
TRH (thyrotropin- releasing hormone)
Hypothalamus
What hormone does the body produce in iodine deficiency?
TSH as iodine required for T3 and T4 production
What hormonal changes result from T4 receptor insensitivity?
Increased TSH
Increased T4
What does GH stimulate?
IGF-1
insulin-like growth factor 1
What does PTH do to phosphate?
Induces excretion. “Phosphate trashing hormone”
What 6 hormones does the anterior pituitary secrete?
FLAT GP
- FSH
- LH
- ACTH
- TSH
- GH
- Prolactin
What 2 hormones does the posterior pituitary secrete?
OA
- Oxytocin
- ADH
By what 3 ways does PTH increase serum calcium?
- increases release of calcium (and phosphorus) from bone
- increase renal calcitriol formation
- decrease renal calcium excretion
What does calcitriol do?
Increases dietary calcium absorption from small intestines
What is the role of Vitamin D in serum calcium and where does it undergo change?
- Vitamin D goes to calcidiol in liver
- Calcidiol goes to calcitriol in kidneys
- Calcitriol is the most metabolically active form of Vit D3, increasing calcium absorption from the small intestines
What do alpha pancreatic cells secrete?
Glucagon
What do beta pancreatic cells secrete?
Insulin
What do delta pancreatic cells secrete?
Somatostatin
Why is C-peptide useful as a clinical measurement?
It is made in equimolar concentrations to insulin therefor can be used as a measurement for how much insulin production.
What is Sipple syndrome also know as?
MEN 2a
When would a Glucagon stimulation test be used?
Suspected phaeochromocytomas not displaying typically high plasma catecholamines
What would be measured in a Glucagon stimulation test?
C - peptide
Cortisol
GH
Why is glucagon stimulation test used as opposed to other tests?
Safer than insulin tolerance test. (ITT)
Three symptoms of carcinoid syndrome?
Diarrhoea
Wheeze
Hot flush
What would carcinoid syndrome indicate?
Neuroendocrine tumour (NET)
What is a a phaeochromocytoma?
Tumour producing catecholamines, typically adrenaline
What are 4 symptoms of phaeochromocytoma?
Headache
Tremor
Palpitations
Sweating
What is Conn syndrome?
primary hyperaldosteonism
Features of Conn syndrome?
Resistant hypertension
Hypokalaemia
Hypernatraemia
Metabolic acidosis
What are the regions of the adrenal gland from outside to in?
Zona Glomerulosa
Zona fasciculata
Zona reticularis
Medulla
(GFR MEDULLA)
What does the Zona glomerulosa produce?
Mineralcorticoids (think mineral on the outside) - Aldosterone
What does the Zona fasciculata produce?
Glucocorticoids- cortisol, corticosterone
What does the Zona reticularis produce?
adrenal androgens- dehydroepiandrosterone (DHEA)
What does the adrenal medulla produce?
Catecholamines- epinephrine (adrenaline), norepinephrine
What can decreases the section of prolactin?
Dopamine
Dopamine agonist used to treat hyperprolactinaemia with prolactinoma?
Bromocriptine
What is the effect of increased PTH on osteoblasts?
causes osteoblasts to make RANK-L leading to osteoclastic formation and calcium release
What is the most common thyroid cancer?
Papillary
How does papillary thyroid cancer spread?
Lymph drainage (“papilliary doesn’t spread to the capillaries”)
How does follicular thyroid cancer spread?
Haematogenously
What thyroid cancers are differentiated?
Papillary
Follicular
What is medullary thyroid cancer associated with?
MEN- 2
What do C cells in thyroid gland produce?
Calcitonin
What thyroid cancer grains rapidly with the worst prognosis?
Anaplastic
What change can be seen on the lower limb in Graves’ disease?
Pretibial myxoedema- orange peel
What is aldosterone?
Steroid hormone produced in Zona glomerulosa.
Acts on kidneys to regulate salt and water balance.
What hormonal changes are seen in Addison’s disease? (primary adrenal failure)
Decreased cortisol
Decreased aldosterone
Increased ACTH
What is produced alongside ACTH?
Melanocyte- stimulating hormone (MSH)
Therefor ‘tanned’ in Addison’s as trying to stimulate adrenal gland
Where is ACTH produced and stored?
Anterior pituitary
When is ACTH released physiologically and what does that result in?
In times of stress
Cortisol release
What hormonal changes are seen in secondary adrenal failure?
Decreased ACTH
Decreased cortisol
(Normal aldosterone)
