The male reproductive system p .1

The male reproductive system
The male reproductive system consists of the testes, genital
ducts, accessory glands, and penis .
Testes produce sperm but also contain endocrine cells secreting hormones such as testosterone, which drives male reproductive physiology. Testosterone is important for spermatogenesis, sexual differentiation during embryonic and fetal development, and control of gonadotropin secretion in the pituitary.
The genital ducts and accessory glands produce secretions required for sperm activity and contract to propel spermatozoa and the secretions from the penile urethra. These secretions provide nutrients for spermatozoa while they are confined to the male reproductive tract. Spermatozoa and the secretions of the accessory glands make up the semen.
testis
Each testis (or testicle) is surrounded by a dense connective tissue capsule, the tunica albuginea , which thickens on the posterior side to form the mediastinum testis . From this fibrous region, septa penetrate the organ and divide it into about 250 pyramidal compartments or testicular lobules.
Each lobule contains sparse connective tissue with endocrine interstitial cells (or Leydig cells ) secreting testosterone, and one to four highly convoluted seminiferous tubules in which sperm production occurs.
Testicular tunicae (covering of the testes)
1. The tunica vaginalis is a serous sac derived from the peritoneum that partially covers the anterior and lateral surfaces of each testis.
2. Tunica albuginea
a. Tunica albuginea is the thick, fibrous connective tissue capsule of the testis.
b. It is lined by a highly vascular layer of loose connective tissue, the tunica vasculosa