Abstract
The reproductive organs of males comprised of primary reproductive organs (testes), excurrent ducts composed of rete testis, vasa efferentia, epididymis, vas deferens, and urethra, accessory sex organs (seminal vesicle, ampulla, prostate and bulbourethral or Cowper’s glands), and ancillary organs (penis and prepuce).
The primary functions of the testes are spermatogenesis and steroidogenesis. The Sertoli cells of the testes aid nutritional support to spermatozoa. The spermatozoa are transported through the excurrent duct and stored in the epididymis for their maturation. The spermatozoa are suspended in the seminal plasma produced from accessory sex organs. The hypothalamic-hypophyseal-gonadal (HPG) axis controls the functions of the testes and other reproductive organs. The HPG axis becomes fully functional at puberty with the activation of the GnRH surge centre and subsequently stimulates the anterior pituitary for FSH and LH secretion. The LH stimulates Leydig cell steroidogenesis. The Leydig cells produce testosterone which facilitates spermatogenesis within the seminiferous tubules. This chapter highlights the functional morphology of the male reproductive system and the factors controlling the functions of each organ. Puberty and its associated events are also discussed. The entire chapter is divided into five sub-chapters to understand different aspects of the male reproductive system.P. K. Das (X) ∙ J. Mukherjee ∙ D. Banerjee
Department of Veterinary Physiology, West Bengal University of
Animal & Fishery Sciences, Kolkata, West Bengal, India
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023
P. K. Das et al. (eds.), Textbook of Veterinary Physiology, https://doi.org/10.1007/978-981-19-9410-4_19
Graphical Abstract
Description of the graphic: Male reproductive system (1) starts to develop from foetal life.
Its functional role is primarily controlled by the Hypothalamus-Pituitary-Gonadal (HPG) axis (2), which triggers the onset of puberty characterized by luteinising hormone secretion at high amplitude (3). The activity of the HPG axis is also influenced by several other factors, viz. stressors (4). Special morphological arrangements, like the testicular thermoregulation mechanism (5) and the blood-testis barrier (6), provide a suitable microenvironment for spermatogenesis (7). The chapter elaborates the detailed internal morphological features of the testis (8) and other associate structures and their functions, viz. steroidogenesis (9). The entire functional characteristics of the system are species-specific and presented in the background of the graphic with the genomic structures.Keywords
Excurrent tract ∙ HPG axis ∙ Puberty ∙ Testes ∙ Androgens
Learning Objectives
• Functional morphology of testes
• Role of excurrent tract and copulatory organs
• Accessory sex glands and their contribution to semen production
• Hypothalamus-Pituitary-Gonadal axis and endocrine regulation of male reproduction
• Biosynthesis of testicular androgens and their biological role
• Puberty in males and its determining factors
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