Gonadal Function

Prepared by:Kashma SoranNahry OmerNergs MuhammadHevi Mustafa

University of Sulaimany

• The gonad is the organ that makes gametes. The gonads in males are the testes, and the gonads in females are the ovaries. The product, gametes, are haploid germ cells. For example, spermatozoon and egg cells are gametes.

Gonads

• The Gonads produce steroid hormones.• Sex steroids control maturation of sex organs

and secondary characteristics.• Control of sex steroids is under the LH and FSH.• These gonadotropins are controlled by

hypothalamic GnRH.

Gonads

GnRH: Gonadotropin Releasing Hormone

• Before puberty, the GnRH conc. is low.• At puberty, its conc. Will rises, stimulating

gonadotropin production, hence sex steroid production.

GnRH concentration

• The principle sex hormone(testosterone)

• Synthesized by leydig cells(LH)

• Sertoli cells(FSH)• Responsibility

Male Gonadal Function

Disorders of male sex hormones

• Over- or underproduction may be due to a variety of factors

• Inherited disorders, long-term illnesses, tumors, lifestyle factors.

• Breast enlargement (estrogen)• Common in newborn boys• Causes:25% idiopathicExcessive estrogen actionExcessive ratio of estrogen to androgendrugs

Gynaecomastia

They are of two type:Primary (testicular deficiency)Secondary (hypothalamus or pituitary defect)• In the secondary, both or one of the

gonadotropins may be absent.

Hypogonadism

• Causes of primary Hypogonadism:

Congenital defect. Acquired defect.

Hypogonadism

• Causes of secondary Hypogonadism:

1. Pituitary tumors.2. Hypothalamic disorders such as Kallmann’s

syndrome. Dynamic tests(GnRH stimulation).

Hypogonadism

• The sex hormone in female include estrogens such as Oestradioll & progesterone.

• Varied conc.• After ovulation, progesterone will increase.• Small amount of testosterone (synthesis)• Increasing SHBG is to increase Oestradiol-like

effect.• Decreasing SHBG is to increasing androgen

effect.

Female Gonadal Function

1. Female secondary sex characteristics.2. Stimulation of follicular growth.3. Development of the endometrium.

Concentrations are high during puberty. after the menopause, Oestradiol Decrease

Despite increasing level of gonadotropins.

Function of Oestradiol

• Include:• Subfertility• Amenorrhea• Oligomenorrhoea• Hirsutism• Virilism

Disorders of female sex hormones

• Causes of hirsutism:• Idiopathic.• Obesity(insulin resistance).

Hirsutism

• Causes of virilism:• tumors of ovary or adrenal• Use of male hormone supplements• Use of steroids to increase muscle mass• Development of ovarian cysts

Virilism

Investigation of an elevated testosterone concentration in a women

• Decreased SHBG is an evidence of elevated androgen

• By measuring of other androgens (androstenedione & DHA sulphate), the

source of testosterone can be pinpointed.

The Androgen screen in women