Sex hormones

Question 1

What is the common precursor for progesterone and androgen production?

Answer 1

Cholesterol

Question 2

What do thecal cells produce?

Answer 2

Theca interna cells produce androgen (androstenedione) a precursor of oestradiol in response to LH. After ovulation the theca interna cells differentiate into small Luteal cells of the corpus Luteum and produce progesterone to maintain and build the endometrium

Question 3

What do granulosa cells produce?

Answer 3

Progesterone and estradiol from androstenedione via aromatase enzyme

Question 4

FSH impact on granulosa cells

Answer 4

To secrete aromatase to convert androstenedione to estradiol

Question 5

LH impact on the thecal cells

Answer 5

Stimulates androgen production by the theca interna and smooth muscle contraction of theca externa to cause ovulation, stimulates development of the corpus Luteum and maintains corpus Luteum in first two weeks of pregnancy before hcg takes over

Question 6

Where is LH produced?

Answer 6

Produced by gonadotropic cells of the pituitary gland (endocrine cells)

Question 7

What are theca cells?

Answer 7

Endocrine cells that surround the maturing follicle (the secondary follicle) and produce androgens for the granulosa cells to convert into estradiol (they have LH receptors and increase output in response to LH), theca externa cells contract in response to surges of LH to release the oocyte, theca cells and granulosa cells form the corpus Luteum after ovulation

Question 8

What is the function of LH in females?

Answer 8

A) Stimulate theca cells to produce androgen substrates for granulosa cells to convert to estradiol
B) stimulate theca externa cells to contract at ovulation, releasing the oocyte
C) maintain the corpus Luteum until pregnancy (beta hcg or menstruation)

Question 9

Which hormones are structurally similar to prolactin?

Answer 9

growth hormone, human placental lactogen

Question 10

Which hormones are structurally similar to FSH?

Answer 10

LH, HCG, TSH

Question 11

What is the function of Inhibin in males and where is it produced?

Answer 11

Produced by sertoli cells in response to androgens, function is to suppress FSH

Question 12

What is the function of FSH in males?

Answer 12

Stimulates the sertoli cells to produce androgen-binding protein to receive testosterone from the leydig cells and inhibin for feedback to the hypothalamus

Question 13

What is the function of testosterone in males?

Answer 13

Stimulate spermatogenesis, maintain structure and function of ducts and accessory glands for reproduction, stimulates secondary sexual characteristics

Question 14

What is the function of LH in males?

Answer 14

Stimulates the leydig cells to secrete androgens (testosterone)

Question 15

What hormones are suppressed by the combined oral contraceptive pill?

Answer 15

FSH, LH and E2 (estradiol) Progesterone inhibits GnRH and therefore LH and FSH levels fall. Oestrogen also inhibits FSH release. Falling levels of FSH reduces stimulation of the granulosa cells to make estradiol (E2)

Question 16

What are luteal cells?

Answer 16

Two types (small luteal- thecal cells and large luteal granulosa cells)

Question 17

What do luteal cells produce?

Answer 17

small luteal (thecal interna) - produce androgens and progesterone, and large luteal (granulosa) produce oestrogen from androgens, progesterone and inhibin A

Question 18

Impact of progesterone on the GI tract

Answer 18

relaxes smooth muscle - reflux, constipation, nausea and vomiting

Question 19

Which oestrogen is E2?

Answer 19

estradiol

Question 20

which oestrogen is E1?

Answer 20

estrone

Question 21

which oestrogen is E1?

Answer 21

estriol

Question 22

What is the most common oestrogen during reproductive years?

Answer 22

E2 estradiol

Question 23

Which oestrogen is most common in menopause?

Answer 23

E1 estrone

Question 24

Which oestrogen is most common during pregnancy

Answer 24

E3 estriol

Question 25

Which oesotrogen is only found during pregnancy and is produced by the fetal level

Answer 25

Estetrol

Question 26

What is the effect of oestrogen on the cardiovascular system?

Answer 26

Vasodilation and preventing atherosclerosis

Question 27

What is the effect of oestrogen on clotting?

Answer 27

Increases factors II/VII/IX/X and plasminogen
Decreases anti-thrombin 3
Increases platelet adhesiveness

Question 28

What is the effect of oestrogen on GIT?

Answer 28

Increased bile acid production and reduced motility

Question 29

What is the effect of oestrogen on metabolism?

Answer 29

Increased HDL, decreased LDL, decreased cholesterol

Question 30

In relation to ovulation, when does an LH surge occur?

Answer 30

24-36 hours before ovulation

Question 31

In relation to the menstrual cyle, how do ooestrogen levels fluctuate?

Answer 31

Gradually increase from day 1 to 14 with the developing follicle, then drop with the surge in LH for ovulation, then gradually increase post ovulation with the drop in FSH and LH and the building of the endometrium

Question 32

In relation to the menstrual cycle, how do progesterone levels fluctuate?

Answer 32

Low levels pre-ovulation, increases post ovulation due to the corpus luteum to maintain the endometrial lining- falls again if no pregnancy

Question 33

In relation to the menstrual cycle, how do FSH and LH levels fluctuate?

Answer 33

FSH and LH are increase gradually day 1-7 (LH stimulates the theca interna to secrete androgens and FSH stimulates the granulosa cells to convert androgens to oestrogen), the levels are at their highest pre-ovulation, with a surge of LH 24-36 hours pre-ovulation. Both levels fall rapidly post ovulation with suppression by rising levels of oestrogen and progesterone

Question 34

Which hormones stimulate increased prolactin production?

Answer 34

TRH, oxytocin, vasopressin, angiotensin II