Endocrinology Flashcards
What is the main effect of glucocorticoid deficiency?
Glucocorticoid = cortisol, aka hydrocortisone
Cortisol stimulates gluconeogenesis
Therefore deficiency causes hypoglycaemia
What effect does aldosterone have on potassium levels?
Loss of potassium from body into urine
What effect does hyperkalaemia have on aldosterone levels?
Hyperkalaemia is a potent stimulator of aldosterone
Name 4 inhibitors of glucagon
Insulin
Uraemia
Somatostain
Fatty / keto acidosis
First line investigation of Addison’s
9am cortisol, U+E
Expected results: low cortisol, low Na, high K
From what cells does a phaeochromocytoma originate?
Chromaffin cells of the adrenal medulla
Which hormone is structurally similar to hPL (human placental lactogen)?
Growth hormone
From where is aldosterone produced?
Zona glomerulosa of adrenal gland
Which hormone inhibits galactopoeisis and lactogenesis?
Dopamine
What is the half life of oxytocin?
5 minutes
Atosiban is an antagonist of which hormone?
Oxytocin
Where does progesterone come from?
Made by luteal cells of ovary from cholesterol
Definition of delayed puberty (in girls)
No breast development beyond age 13
Effect of pregnancy on thyroid function
Decreased TSH
Increased total T3 and T4 (although free T3 and T4 levels drop)
Which hormone is structurally similar to FSH?
TSH
Teratogenic effects of carbimazole
Choanal atresia
GIT defects
Omphalocele
Aplasia cutis
How are FSH, LH, and oestradiol affected by COCP?
All reduced
Which hormones do the corpus luteum make
Progestérone
Estradiol
Which hormones inhibit prolactin
Dopamine
Somatostatin
Breast feeding stimulates which hormone from hypothalamus
Oxytocin
Which cells in testes make testosterone?
Leydig
Which hormones do chromaffin cells make (where are chromaffin cells??)
Chromaffin cells are in adrenal medulla
They make:
Adrenalin
Noradrenaline
Dopamine
What is a Meckel’s diverticulum and what percentage of population have one?
2%
Failure of omphalomesenteric duct (/ yolk sac stalk)
Embryological origin of external carotid
1st pharyngeal arch
Where is cortisol produced
Zona fasciculata
Upper limit of HbA1c for safe in pregnancy
86 (10%)
Definition precocious puberty in girls
Secondary sexual characteristics before age 8
Embryological origin of CN7
CN7 = facial nerve
Embryological origin = 2nd pharyngeal arch
Definition of puberty in girls
Becoming capable of sexual reproduction
Which hormone peaks at day 21 of 28 day menstrual cycle
Progesterone
Where are ADH and oxytocin synthesised?
Synthesis = hypothalamus
Released from posterior pituitary
When during menstrual cycle does LH surge
24-36 hours before ovulation
Which 3 hormones are structurally similar to HCG
TSH
FSH
LH
Most common cause of hyperprolactinaemia
Hypothyroidism
Other causes:
H2 antagonism
PCOS
Pregnancy
Chest wall surgery
What form is calcium in the body
Calcium phosphate
High PTH + high Ca2+ = what type of hyperparathyroidism?
Primary
or.. tertiary if with renal failure
For which group of patients / ovulation disorder is pulsatile GnRH a suitable treatment?
WHO Group 1 ovulation disorders
ie hypothalamic pituitary failure (incl anorexia, compulsive exercisers etc)
Most common cause primary hyperaldosteronism
1ary hyperaldosteronism = Conn’s
Most common cause = bilateral idiopathic adrenal hyperplasia
What is a typical blood electrolyte of Conns?
Hypokalaemia
Hypernatraemia
Hypocalcaemia
Hypertension
Effect of obesity on sex hormone binding globulin (SHBG)
Reduces SHBG
Therefore more free testosterone, more hirsutism
Correct response to increased calcitonin
Increase osteoblast
Decrease phosphate
(Calcitonin comes from c-cells in thyroid in response to high calcium)
