endocrine

Question 1

in the adrenal gland, cholesterol is converted to pregninolone to 17 OH progesterone. What is it then converted into?

Answer 1

aldosterone, cortisol and androgens

so even though ACTH is mainly to stimulate cortisol production, it also causes increased aldosterone and androgens

21 hydroxylase and 11 hydroxylase are needed for production of aldosterone and cortisol but NOT androgens

Question 2

describe pathophysiology of CAH

Answer 2

21 (or 11) hydroxylase deficient
so 17 OH progesterone cannot become aldosterone or cortisol (which requires 21 or 11 hydroxylase)
so it all becomes androgens
there’s lots of ACTH made made trying to produce cortisol and aldosterone because there’s no negative feedback
so there is hyperplasia of the adrenal glands from all the ACTH

Question 3

describe phenotype in CAH

Answer 3

virilization of female fetus due to excessive androgens (female pseudohermaphrodism / ambiguous external genitalia) (but they have normal internal female organs)
but in a male, the excess androgens are not a big deal for the external genitalia

also, due to aldosterone deficiency, there is low sodium, high potassium
and low BP from cortisol deficiency

Question 4

The rate of growth hormone secretion follows a circadian rhythm. When is the highest peak of growth hormone release?

Answer 4

early sleep

Question 5

Is hyper or hypo-thyroidism a cause of hyperprolactinaemia?

Answer 5

hypO

Question 6

is prostaglandin autocrine, endocrine, axocrine, paracrine or eccrine?

Answer 6

paracrine
a secretion released by (endocrine) cells into the adjacent cells or surrounding tissue rather than into the bloodstream.

Question 7

name the 3 types of sex hormone

Answer 7

The sex hormones include the androgens, estrogens, and progestogens
(important for when you are asked ‘where are androgens made’. There are some androgens in women, e.g. androstenedione)

Question 8

What is the purpose of the fetal adrenals producing DHEA

Answer 8

The fetus manufactures DHEA, which stimulates the placenta to form estrogen, thus keeping a pregnancy going.

Question 9

What cancers have Cushings as a paraneoplastic syndrome?

Answer 9

Small Cell lung cancer
Pancreatic cancer

Question 10

What cancers have SIADH as a paraneoplastic syndrome?

Answer 10

small cell lung cancer
Brain tumours

Question 11

which cells make androgens?

Answer 11

male - leydig cells (TT, DHEA, androstenedione - in presence of LH)
and sertoli cells?

female - theca cells

Question 12

describe prostaglandin types and actions in the menstrual cycle

Answer 12

PGF2 alpha - vasoconstricts the endometrial vessels during menstruation and contracts the smooth muscle of the myometrium.

PGE2 vasodilates the vessels of the endometrium

PGI2 relaxes smooth muscle, vasodilates the vessels of the myometrium and inhibits thrombocyte aggregation.

Question 13

(according to given answers) what is the Ig that increases in a term pregnant cervix?

Answer 13

IgA

Question 14

which hormone increases the amount of glucose that is available to the fetus?
How does it do it?

Answer 14

hPL
by increasing maternal resistance to insulin
decreasing maternal glucose utilisation
increasing lipolysis (as free fatty acids can’t cross the placenta but can be used by mum as energy)

Question 15

hPL is a potent agonist at which receptor?

Answer 15

prolactin

Question 16

effect on glucagon of protein-rich meal

Answer 16

apparently it increases, according to a bit of google research…

Question 17

most common cause of ACTH syndrome

Answer 17

IATROGENIC STEROIDS

Question 18

what does inhibin do? What secretes it?

Answer 18

inhibin inhibits FSH secretion

granulosa (follicular) cells
and
sertoli cells
and
placenta
and
corpus luteum

Question 19

PTH function in the kidney is…

Answer 19

reduce calcium excretion

Question 20

the pulsatile release of GnRH is due to…

Answer 20

oestrogen (according to the answers given)

Question 21

where are ADH and oxytocin synthesised?

Answer 21

hypothalamus

Question 22

T4 to T3 ratio

Answer 22

14:1

Question 23

progesterone has how many carbons

Answer 23

20

Question 24

where, other than the hypothalamus, secretes GnRH

Answer 24

duodenum

Question 25

TRH is made in which nucleus of the hypothalamus? And how many copies of TRH are made from its precursor molecule?

Answer 25

paraventricular nucleus 6 copies

Question 26

somatotrophs make up what percentage of anterior pituitary cells? What do they make?

Answer 26

50%, GH

Question 27

lactotrophs make up what percentage of anterior pituitary cells? What do they make?

Answer 27

20%, Prolactin

Question 28

GnRH is from which nucleus of the hypothalamus? What is its embryological origin?

Answer 28

Preoptic. Neural crest.

Question 29

COCP missed pill rules: If you're late restarting the pill after the pill-free week, with or without UPSI

Answer 29

if >48h late and had UPSI in the pill-free time, consider emergency contraception +/- UPT at least 21 days after the UPSI Whether UPSI or not in that interval, use additional barrier contraception until 7 consecutive pills have been taken

Question 30

COCP missed pill rules: in week 1 of pill-taking, missing one pill or week 2 or 3 of pill-taking, missing one pill

Answer 30

week 1, if one missed pill and otherwise sterling compliance to the regime in week 1 and the week before the pill-free interval then it's okay week 2/3, if one missed pill but otherwise sterling compliance in past 7 days then it's okay

Question 31

for COCP missed pill rules, if you forget 1-7 pills in weeks 2 or 3 specifically, what are the rules?

Answer 31

If you took the pills beautifully in the preceding 7 days, then you don't need emergency contraception If you forgot 1 pill, you don't even need additional barrier contraception But if you forgot 2 - 7 pills, you should use additional barrier contraception for 7 days

Question 32

for COCP missed pill rules, if you forget more than 7 consecutive pills, what do you do?

Answer 32

Take a pregnancy test restart the pill additionally use condoms for 7 days take another pregnancy test 21+ days after the last act of UPSI

Question 33

POP missed pill rules for norethisterone, desogestrel and drosperinone, respectively

Answer 33

norethisterone (first generation): if >3h late use condoms for 48h and emergency contraception if you had UPSI in pill-free time desogestrel (third generation): if >12h late use condoms for 48h and emergency contraception if you had UPSI in pill-free time drosperinone (fourth generation): if >24h late use condoms for 7 days and emergency contraception if UPSI in interval + not having taken 7 preceding active pills (drosperinone regime has 4 inactive pills)

Question 34

hPL plateaus after what gestational age?

Answer 34

35 weeks