**3. Spermatogenesis**

*Innovations in Assisted Reproduction Technology*

during gametogenesis [4, 5].

**2. Physiology of male sexual organ**

lysosomes of a typical cell, including hyaluronidase (having the ability to digest proteoglycan filaments of tissue) and powerful proteolytic enzymes which can digest proteins having an important role in the process of oocyte fertilization. The flagellum is divided into three regions: mid piece, principle piece and terminal piece. A central complex of microtubules covered by outer dense forms the axoneme. Mitochondria are present in the mid piece which surrounds the outer dense fibers and neighboring axoneme. The principle part of the flagellum is mostly comprised by the existence of fibrous sheath which surrounds the dense fibers and axoneme. In higher vertebrates these dense fibers and fibrous sheath are developed due to internal fertilization and these are cytoskeletal material of sperm flagellum [1]. The plasma membrane as in sperm head surrounds the flagellum tightly and contains scattered cytoplasm. Invertebrate's sperm usually have an acrosome in the head region and mitochondria and an axoneme in the flagellar region but the accessory or additional cytoskeletal elements are absent [2]. To achieve the fertilization the acrosome, have an enzyme which plays a key role to penetrate into egg. The flagellum of the sperm contains the source of energy that generates sperm motility required to reach the egg. All these characteristics of sperm are necessary to deliver the genetic material exists in sperm nucleus to egg. After that, zygote is formed by the fusion of haploid pronuclei of male and female, and thus development initiates. In most mammals, the nucleus of haploid sperm carries the sex chromosome decides the sex of resulting animals [3]. The genome of both maternal and paternal parents is essentially required to proceed the normal development, generally due to distinctive genes imprinting in males and females

This chapter gives center of attention on the unique features of mammalian spermatozoa with especial consideration to molecules presently known that enrich to the structure and function of sperm. The main topics contemplated are; physiology of male sexual organ, spermatogenesis, sperm count, heritable effect on human sperm structure, regulation of sperm motility, effect of oxidative stress on male reproductive system, sources of reactive oxygen species in seminal plasma, physiological role of ROS in seminal plasma, consequence of Oxidative Stress on male Reproductive System, management and prevention of oxidative stress, correlation between biol-

ogy of male reproduction and sleep and role of inflammation in infertility.

The favorable outcome of male reproductive system depends mainly upon the cohesive function of vast array of tissues. It comprises of assembly of sperm in the testes, sperm maturation in epididymis, secretion of seminal fluid by addition sex glands, deliver sperm into the reproductive tract of female, erection of penis, emission and final ejaculation. Fertilization of the egg requires the motility of sperm, successful capacitation and acrosomal reaction. These entire needs are dependent directly or indirectly on the secretion of testosterone hormone by the Leydig cells. The testis of male is comprised of up to 900 coiled seminiferous tubules, in which the sperm is formed and each seminiferous tubule exceeds up to 1 meter long in average. The sperm then discharged into one more coiled tube which is about 6-meter long known as epididymis. The epididymis enlarges into vasa deferens that infiltrates into prostate gland. There are two seminal vesicles and the material (Is secreted) from both the ampulla and seminal vesicles. The excretion from both the prostate gland and seminal vesicles enters into the ejaculatory duct through the body of prostate gland and then vacant into the internal urethra. Mucus released

**24**

The process of spermatogenesis takes place in each of the testis tubules. In this process the spermatozoa are produced by the population of germ cells (spermatogonia) through process of mitosis and meiosis. This entire spermatogenesis process starts during the onset of puberty and last till the old age. This process involved various stages starting with germ cells formation in the germinal epithelium and followed by continuous development into primary and secondary spermatocytes. These spermatocytes finally developed into functional spermatozoa. Spermatogenesis is extremely well-ordered process; male germ cells proliferate and differentiate rapidly and the modulation of spermatogenesis occurs at the extra testicular and intra testicular level and can be dispersed ubiquitously. As aforementioned, spermatogonia originated from the primordial germ cells that migrate into the genital ridge of the indifferent gonads, during embryo development and are present in two to three layers in seminiferous tubules. At puberty, the spermatogonia starts mitotic division, proliferate and differentiate continuously to form mature sperm cells [7] (**Figure 1**).
