Gonadal Function

Question 1

What are the two anatomical units of testes?

Answer 1

Seminiferous tubules
Interstitium

Question 2

2 physiological functions of the testes

Answer 2

Spermatogenesis
Hormonogenesis - testosterone secretion controlled by 2 pituitary hormones: follicle stimulating hormone and luteinising hormone

Question 3

Testosterone

Answer 3

Synthesised by cholesterol trapped by endocytosis or synthesised by leydig cells in the testes
Active form => DHT
DHT binds androgen receptor in cytoplasm => translocates to nucleus = > transcription of AR genes

Question 4

AR pathway ____________ activated in prostate cancer.

Answer 4

Constitutively

Question 5

2x physiological actions of testosterone

Answer 5

Prenatal development -> male sexual differentiation
Post-natal development -> puberty

Question 6

Estrogens

Answer 6

Estrodiol
Promotes secondary sexual characteristics e.g. breasts

Question 7

Progesterone

Answer 7

Induces activity of endometrial glands
Dominant hormone in the lutes phase

Question 8

Target organ and principle effect for FSH, LH and TSH.

Answer 8

FSH -> ovaries and testes -> follicle/egg or sperm development
LH -> ovaries and testes -> ovulation/growth of corps luteum
TSH -> thyroid gland -> growth of thyroid gland and secretion of thyroid hormone

Question 9

Follicular phase

Answer 9

Low estrogen and progesterone
⬆️FSH stimulates estrogen => endometrium thickening

Question 10

Luteal phase

Answer 10

Estrogen peaks 1 day before ovulation causing peak in LH & ovulation 36 hours later
Leuteinisation of the Graffian follicle -> corpus luteum -> oestrogen & progesterone (maintain optimum conditions for implantation if the ovum is fertilised)

Question 11

__________ stimulates differentiation of Wolffian duct into male sex organs.

Answer 11

Testosterone

Question 12

True hermaphroditism and its causes:

Answer 12

Ovary and testes tissue present

Causes: fusion of two zygotes or mutation in SYR gene

Question 13

Pseudo-hermaphroditism

Answer 13

Primary sex characteristics of one sex but develops secondary characteristics that are different from gonadal tissue

Question 14

Causes of female pseudohermaphroditism

Answer 14

Excess foetal androgens
Excess maternal androgens

Question 15

Causes of Male Pseudohermaphroditism

Answer 15

Failure to produce testosterone
Failure to utilise testosterone

Question 16

Mullerian inhibitory factor

Answer 16

Produces atrophy of the Müllerian duct

Question 17

Precocious puberty

Answer 17

Earlier than normal
Cause can be idiopathic, peripheral such as adrenal or central such as brain lesions

Question 18

Treatment for precocious puberty

Answer 18

Leuprolide

Question 19

Klinefelters syndrome

Answer 19

Primary hypogonadism
Extra X chromosome
High levels of FSH and LH
Low testosterone
Small testicles; male breasts
Treatment with testosterone replacement therapy

Question 20

LH,FSH low/normal

Answer 20

Secondary hypogonadism

Question 21

LH, FSH high

Answer 21

Primary hypogonadism

Question 22

Kallman’s syndrome

Answer 22

Rare genetic condition
Failure to start or finish puberty
Absent sense of smell