Question

explain the physiological effect on the reproductive system and endocrine system for andregen intensivity syndrom and cogenital adrenal hyperplasia

Answer 1

In Androgen Insensitivity Syndrome, the body is not responsive to the testosterone secreted by the testis. The chromosome is 44+XY. Y chromosome has SRY gene which is responsible for gonads determination. If it is present then gonads are testis. If not, then gonads are ovaries. The testis has two cells Sertoli cells and Leydig cells. Sertoli cells secrete Anti-Mullerian hormone which causes regression of Mullerian duct which forms the female internal genitalia. The Leydig cells secrete testosterone which performs two functions:

1. It promotes wolffian duct to form male internal genitalia (seminal vesicles, epididymis, ejaculatory duct, vas deferens).
2. It is converted into Dihydrotestosterone which forms the male external genitalia.

When Testosterone receptors are defective, testosterone cannot bind to them and cannot perform its functions. Therefore, the male internal genitalia is not formed and Dihydrotestosterone cannot act. Therefore the external genitalia resembles female's. This is called Ambiguous genitalia (sex of the baby cannot be determined by looking at the genitalia).

CONGENITAL ADRENAL HYPERPLASIA

In this, steroid pathway becomes defective. Most common enzyme deficiency is 21-Hydroxylase deficiency.

In enzyme deficiency, the levels of cortisol and becomes less. When aldosterone is less, it leads to Salt and water wasting. Negative feedback on AC TH is gone therefore the levels of adrenocorticotropic hormone increases. ACTH further tries to stimulate this pathway. The levels of progesterone, 17-hydroxyprogesterone and androgens are increased. Increased androgens are responsible for following features:-

• External genitalia of female resembles male's (ambiguous genitalia)
• Clitoromegaly
• Phallus formation
• Labioscrotal fusion
• Heterosexual precious Puberty
• Virilisation
• Short stature
• Female can conceive but chances are less.