- November 10, 2015
- Posted by: emobile
- Category: Hot or Not
It can be as a result of deficiency in sperm formation, sperm concentration or sperm transport. Sperm formation is known to be under the control of the hypothalamic-pituitary-gonadal axis, a close loop circuit with a feedback control by testosterone. The hypothalamus secreting gonadotropin realeasing hormone (GnRH) which acts on the anterior pituitary gland and stimulates it to produce Luteinizing hormone (LH) and Follicular stimulating hormone (FSH). These are glycoproteins which released into the circulating system.
Their production is inhibited by prolactin, a hormone produced by the pituitary gland under the influence of thyroid releasing hormone (TRH) and vasoactive intestinal peptides (VIP); these hormones are produced by the hypothalamus. LH acts on leydig cells int the testes and cause them to produce testosterone while FSH acts on Sertoli cells in the semniferous tubules, supporting, nourishing and protecting the germ cells in an immunologiocally enhanced environment. Sertoli cells also produces inhibin which regulates the production of GnRH as well as Androgen binding protein which regulates the activity of androgen in the testes. Germ cells in the seminiferous tubules undergoes differentiation to form spermatozoa and these are transported through the tubuli reti, rete testes, ductuli efferentes then to the epididymis.
From here it is transported to the vas defens and to the ejaculatory duct at the point where it meets with the seminal vesicle. The seminal vesicle contributes 40-80% of ejaculate volume and produces fructose, prostaglandins and other coagulating agents. It then empties in the veromontanum of the prostate gland. The prostate gland produces enzymes and anticoagulum which liquefies the sperm. The bulbourethral gland and periurethral gland also contributes the seminal volume serving mainly to lubricate the urethra. Ejaculation is aided by rhythmic contraction of the smooth muscles surrounding the urethra and by contraction of the pelvic muscles. Failure of any of these outlined pathway will result to male infertility.