Endocrinology Flashcards
Peptide precursor of MSH and ACTH?
POMC
Which measurement is used to test if DM 1 patients haves topped producing insulin?
Plasma C-peptide level
(not effected by IM insulin)
What is a consequence of central diabetes insipidus?
Hypernatraemia
(produces large quantities of dilute urine)
Which GLUT transporter is the primary transporter in pancreatic B cells?
GLUT2
What effect does a ^ in ATP have on K atp channels in B cells?
Less ATP-sensitive K channels open
(ATP closes these)
Which surgical procedure is used to access the pituitary?
Transsphenoidal surgery
What effect on insulin would a rise in intracellular ATP?
Insulin secretion would increase
In which nucleus of the hypothalamus is ADH/oxytocin synthesised?
Paraventricular nucleus
(supraoptic & paraventricular nuclei)
Define hormone
A chemical signal produced in endocrine glands/tissues that travel in the bloodstream to cause an effect on other tissues.
Whats pituitary apoplexy?
Bleeding/impaired blood supply to the pituitary gland
(diplopia, hypopituitarism,)
What class of hormone is insulin?
Water soluble hormone
Which neurotransmitters are released from primary neurones to stimulate appetite?
NPY & AgRP (agouti-related peptide)
What would the oral glucose tolerance say on patients with acromegaly?
GH wouldn’t drop
What’s the embryological origin of the anterior pituitary lobe?
Arises from an upgrowth of ectodermal cells from the primitive pharynx
2 most significant factors in the aetiology of metabolic syndrome?
Insulin resistance & Central obesity
Metabolism of insulin order?
- Pre-proinsulin cleaved
- Proinsulin folding in ER
- Transport to golgi
- Packaged into vesicles
- Removal of C-peptide
What is the half life of insulin?
5 mins
What class of hormone is cortisol?
Steroid hormone (synthesised from cholesterol)
What class of hormone is T3 & T4?
Amine hormone (synthesised from tyrosine)
A child shows poor development, constipation and muscle weakness after her mother had iodine deficiency during pregnancy. What is the diagnosis?
Cretinism (congenital hypothyroidism)
What happens after a1 adrenergic receptors activate?
G protein coupled receptor
Increase in the conc of IP3
How do parathyroid gland cells sense Ca plasma conc?
By G protein coupled receptors that are activated by calcium
What proportion of T3/T4 is free?
1%
What molecule transports T3/T4?
Thyroxine-binding globuin (TBG)
What is the half life of T3 and T4?
T3 - 1 day
T4 - 5 - 7 days
What substance is secreted by parafollicular cells in the thyroid?
Calcitonin
Where is calcitonin secreted from?
Thyroid gland
What is the most common cause of secondary adrenal failure?
Hypopituitarism resulting in ACTH deficiency
What would blood results show in a patient with cushing’s syndrome from an adrenal tumour?
High cortisol
Low ACTH (-ve feedback)
How would you treat rapid corticosteroid withdrawl?
I.v. hydrocortisone (cortisol) and fluids
Symptoms of addison’s disease?
Fatigue
Weakness
Anoxeria
Weight loss
Nausea
Abdo pain
What class of hormone is TSH?
Glycoprotein hormone
A patient has normal T3/T4 but undetectable TSH, what is her diagnosis?
Subclinical hyperthyroidism
What is insulin’s effect on phosphofructokinase in the liver?
Increased activity
For how long can creatine phosphate be used to replenish ATP for maximal exertion?
5 seconds
What shuffle transports fatty acids?
Carnitine shuffle
Which hormones are produced by the hypothalamus?
3 Gs & CPT And Others
GnRH (gonadotropin releasing hormone)
GHRH (growth hormone releasing hormone)
GHIH (growth hormone inhibiting hormone)
CRH (corticotropin releasing hormone)
PIH (Prolactin inhibiting hormone)
TRH (thyroid releasing hormone)
ADH (anti-diuretic hormone)
OT (oxytocin)
Which hormones are produced by the anterior pituitary?
Them (TSH) (thyroid stimulating hormone)
Girls (GH) (growth hormone)
Are (ACTH) (adrenocorticotropic hormone)
Like (LH) (luteinising hormone)
Pretty (PRL) (prolactin)
Fat (FSH) (follicle stimulating hormone)
Which drug is contraindicated in thyroid disease or can harm the thyroid gland?
Amiodarone (K+ channel blocker - class III)
Drug contains iodine
