Contraception A<unk> ectomy is a method of contraception in which the<unk> a<unk> ia are permanently cut, though in some cases it can be reversed. A modern variation, which is also known as a<unk> ectomy even though it does not include cutting the<unk> , involves injecting an obstructive material into the ductus to block the flow of sperm. Investigational attempts for male contraception have focused on the<unk>  with the use of the intra<unk>  device and reversible inhibition of sperm under guidance. Disease The<unk>  may be obstructed, or it may be completely absent in a condition known as congenital absence of the<unk>  (CAVD, a potential feature of cystic fibrosis), causing male infertility. Acquired obstructions can occur due to infections. To treat these causes of male infertility, sperm can be harvested by testicular sperm extraction (TESE), microsurgical epididymal sperm aspiration (MESA), or other methods of collecting sperm cells directly from the testicle or epididymis. Uses in pharmacology and physiology The<unk>  has a dense sympathetic innervation, making it a useful system for studying sympathetic nerve function and for studying drugs that modify neurotransmission. It has been used: * as a bioassay for the discovery of enkephalins, the endogenous opiates. * to demonstrate quantal transmission from sympathetic nerve terminals. * as the first direct measure of free Ca2+ concentration in a postganglionic nerve terminal. * to develop an optical method for monitoring packeted transmission (similar to quantal transmission).
Vas deferens
Corpus cavernosum penis
Penis
Collyrium
Subfornical organ
Meibomian gland
Uterus
Ovary