Gonadotropic hormones and their effect on ovaries

The ovarian changes during the female sexual cycle depend completely on the hormones FSH and LH secreted by the anterior pituitary.

Androgen

Androgenic steroid hormones are the male sex hormones, their function are:

1- Differentiation of the male reproductive tract and brain during fetal life.

2- Stimulation of the testis descend during the last three months of gestation.

Interstitial cells of leydig

The principal function of leydig cells is to produce androgens. Leydig cells begin to secrete androgens during the 7th week of fetal life in response to hCG (human chorionic gonadotropin) which is

Inhibin + Androgen binding protein + Estrogen

Inhibin

Is a protein that selectively inhibits the synthesis and secretion of FSH by the pituitary gonadotropes.

Sertoli cells

Sertoli cells have many functions:

1- Provision of nutrients to germ cells.

2- Synthesis of multiple proteins that are secreted into the luminal fluid including caeruloplasm

testes

The testes serve three main functions:

1- Production of gametes.

2- Secretion of hormones that cause differentiation of the brain and reproductive tract during fetal and neonatal development, maintain the structure and function of the reproductive tract, it promotes the development of sexual characteristics.

Anatomy of male reproductive system

The testis composed of 900 coiled seminiferous tubules, each 

average more than 5 meters length in which the sperms are 

found. Between the seminiferous tubules are the interstitial 

cells of leydig for synthesis of testosterone. The sperms pass 

from the

Effect of temperature on spermatogenesis

Normal temperature to spermatogenesis is 32o C, increasing temperature as hot bath of 48oC for 30 minutes reduces sperm count to 90%, sperms ca

Neuroendocrine Regulation of the Testis

Neuroendocrine Regulation of the Testis:-

In hypothalamus GnRH secreted in pulses one pulse every 3 hours, if secreted continuously the anterior pituitary not responds to it, anterior pituitary secrete

Function of seminal vesicle

Function of seminal vesicle:-

The secretion of seminal vesicle form 60% of total volume,its mucoid contain fructose,citric acid and other nutrients,also prostaglandin and fibrenogin

Semen

Semen:

The fluid that ejaculated at the time of orgasm contains sperms and secretion of seminal vesicle, prostate and cowpers gland.

Normal semen volume 2.5-5 ml,

Function of prostate gland

The prostate gland secrete a thin milky fluid (30% of total vol.) contain citrate ions, calcium ions, phosphate ions and clotting

Maturation of sperm in epididymis

The sperm after its formation in the seminiferous tubules pass into the epididymis, they remain for 18-24 hours and become capable of motility, although in the epididymal fluid there are inhibitory

Formation of sperms

Formation of sperms:-

The sperms is composed of head and tail , the head composed of condensed nucleus with only a thin cytoplasmic cell membrane layer around its surface.

Hormonal factors that stimulate spermatogenesis

Hormonal factors that stimulate spermatogenesis :

1. LH secreted by anterior pituitary stimulates leydig cells to secrete testosterone.

2. Testosterone secreted by leydig cells is essential for growth and division of germinal cells in forming sperms.

Acrosome reaction

Acrosome reaction

The acrosome enzyme hyaluronidase and proteolytic enzymes released to open a pathway

Spermatogenesis (sperms formation)

The seminiferous tubules contain large number of germ cells called spermatogonia, located in 2-3 layers. In the 1st stage of spermatogenesis, type A spermatogonia divided 4 times (mitosis) to form 16 more