Testes
these are pair of oval glands measuring approx. (5cm, (2in) in length 2 1/2cm 1in in diameter and each testis weighs about 10-15 grams in the human, it must be understood that each dogs testes i relative to their size, Great Danes will have much larger testes than a smaller Jack Russell. the main function of the testes is to produce sperm (spermogensis) they also produce hormone (testosterone), within the testes seminiferous tubules are surrounded by interstitial tissue, in this tissue is a type of cell called the Leydig, these cells become activated by the luteinising hormone (LH), produced by the pertuitary gland, they start synthesizing testosterone, this hormone (testosterone) comes in to production at the onset of sexual maturity (again the age of the dog will vary from 6-9 months to 12-18 months depending on the breed).
(Anon., n.d.).
the process of sperm production is called spermatogenesis, and this is produced in the seminiferous tubules, in a human spermatogenesis takes approx 65-70 days, the ducts and glands carry the spermatozoa in a special secretions to the outside of the body so that the may be deposited inside the female (sperm is 5% the volume of semen). the testes is a tubular gland and is surrounded by a fibrous casual, the tunica albuginea, and this is divided into several hundred compartments by a fibrous tissue septa. each compartment contains several seminiferous tubules. each tubule is about 50cm long (in humans) and is coiled in on itself, all the tubule drain into one border of the testis, into larger collecting tubules called Vasa efferentia (small ducts) which coil in a mass called the Epidimis and are found at the surface of the testis (Softpedia, 2006)
between the seminiferous tubules is the connective tissue and this contains blood vessels and glandular cells the interstitial cells from above Leydigs cells. Seminal vesicles secrete seminal fluid this makes up two thirds of the semen, seminal fluid is a thick substance because it contains mucus, protein ad fructose, this is the sperms sauce of energy, it also contains a modified fatty acid called Prostaglandins this stimulates the contractions in the female reproductive tract (Tortora & Grabowski, Reynolds, 1996).
the prostrate gland contributes 1/4 to 1/3 of the volume of the of the semen and this is a thin milky fluid, this prostrate fluid makes the uterine environment more hospitable to the sperm, the prostrate is also responsible for secreting a clotting enzyme this enzyme acts on the protein within he seminal fluid and converts it to a gelatinous mass (Tortora & Grabowski, Reynolds, 1996)
the process of sperm production is called spermatogenesis, and this is produced in the seminiferous tubules, in a human spermatogenesis takes approx 65-70 days, the ducts and glands carry the spermatozoa in a special secretions to the outside of the body so that the may be deposited inside the female (sperm is 5% the volume of semen). the testes is a tubular gland and is surrounded by a fibrous casual, the tunica albuginea, and this is divided into several hundred compartments by a fibrous tissue septa. each compartment contains several seminiferous tubules. each tubule is about 50cm long (in humans) and is coiled in on itself, all the tubule drain into one border of the testis, into larger collecting tubules called Vasa efferentia (small ducts) which coil in a mass called the Epidimis and are found at the surface of the testis (Softpedia, 2006)
between the seminiferous tubules is the connective tissue and this contains blood vessels and glandular cells the interstitial cells from above Leydigs cells. Seminal vesicles secrete seminal fluid this makes up two thirds of the semen, seminal fluid is a thick substance because it contains mucus, protein ad fructose, this is the sperms sauce of energy, it also contains a modified fatty acid called Prostaglandins this stimulates the contractions in the female reproductive tract (Tortora & Grabowski, Reynolds, 1996).
the prostrate gland contributes 1/4 to 1/3 of the volume of the of the semen and this is a thin milky fluid, this prostrate fluid makes the uterine environment more hospitable to the sperm, the prostrate is also responsible for secreting a clotting enzyme this enzyme acts on the protein within he seminal fluid and converts it to a gelatinous mass (Tortora & Grabowski, Reynolds, 1996)