chapter 28 lecture 1 is introduction to the reproductive system and male reproductive system anatomy sexual reproduction is the process through which organisms produce offspring through germ cells that are called gametes the organs of reproduction are called gonads and they're the ones that produce the gametes which are the sperm and egg as well as secrete hormones um sexual hormones there are also ducts through which the gametes are transported and stored and accessory sex glands gynecology is the branch of medicine concerned with diagnosis and treatment of diseases of the female reproductive system and urology is in addition to the study urinary system also includes diagnosis and treatment of diseases and disorders in the male reproductive system so in the male reproduction system we have testes which produce sperm and a series of ducts through which a sperm travels and accessory sex glands that add secretions to the sperm and then some support supporting structures including the penis i apologize this shows the male reproductive system here is the test testis held in the scrotal sac going up the side the posterior side is a comma-like organ called the epididymis that stores sperm and allows them to mature then the vas deferens is a tube a duct that fuses with the seminiferous gland uh i mean the sun excuse me the seminal vesicle excuse me and it forms the ejaculatory duct the seminal vesicles supplies secretions that are added to the sperm as well as the prostate gland does the same thing we've got the prostatic urethra and then the sperm goes into the it goes from the prostatic urethra into the membranous urethra and then into the spongy or penile urethra before it does secretions from the bulbourethral gland are added to it it travels down the spongy urethra and is ejaculated the penis has um three pieces of erectile tissue two of them are the corpora cavernosum penis and then surrounding the spongy urethra is the corpus spongios and penis the glands penis is also called the head of the penis it has a ridge called the corona and is covered by a prep use for foreskin this is just showing a cadaver the same structures on a cadaver so we'll start with the scrotum the scrotum it supports the testes it's a sac and inside it has a septum that divides it into two separate regions and each has a single testis in it there are two muscles called the dartos and the cremaster muscle and here we'll look at the scrotal sac the cremaster muscle goes down through the spermatic cord and it's involved in elevation and dissension of the testes testes have to be a few degrees lower than body temperature in order for the optimal production of sperm the dartos muscle is involved in wrinkling of the sac when it contracts it wrinkles it there's a line that goes up the center of the sack called the rafe and the interior there is the scrotal septum that divides it into two separate regions each testis has several layers of connective tissue around it starting with external spermatic fascia and then the internal spermatic fascia and then the tunica vaginalis which is part of the peritoneum since the testes form near the kidneys in a fetus when they descend down through the inguinal canal they pick up a piece of the peritoneum and take it with them and that's the tunica vaginalis then we have the tunica alberginia and then the testis itself underneath the tunica virginia the epididymis again it's a comma-shaped structure that goes down the posterior side involved in sperm maturation and storage and then here we have the spermatic cord spermatic cord has nerves in it autonomic nerves it has arteries veins lymphatics as well as the vas deferens which is involved in transporting the sperm this is a cross section of penis here's the suspensory ligament of the penis and there's also a fun deformed ligament of the penis and then it too is going to have a tunica alvargini on a tunica the tunica alberguinia is this area right around here and there are three pieces of erectile tissue the two corpora cavernosa penis and the corpus spongiosum penis that surrounds this spongy urethra so the testes contain seminiferous tubules and that's where sperm cells are made uh embedded among them the spermatogenic cells that produce the sperm are these sertoli cells or sustentacular cells these sort of look like puzzle pieces and they have tight junctions in between them that help to form the blood test this barrier the blood test this barrier protects the sperm the antigenic surface antigens on the sperm from being recognized as being foreign by our immune systems and if there is any breach of these tight junctions and a male's immune system sees the sperm they'll mount an immune response against it so a man can actually be allergic to his own sperm and suffer the symptoms of allergy when he ejaculates so here we have the tunica vaginalis and then the tunica albuginea tunica albergini is the inner layer and it has extensions that divide the testis into lobules these extensions are called septi and within each lobule is about two to three seminiferous tubules there's about two to three hundred of these lobules sperm forms within these is released into the straight tubule from there it goes to the rete testis from there it goes to the efferent ducts and from there to the epididymis the epididymis has a head a body and then down here is its tail next to the uh going out from the tail of the epididymis is the vas deferens and that transports sperm up into the peritoneal up into the perineum where um secretions are added to it and ejaculation occurs so there you can see that tunica vaginalis again it's part of the peritoneum and it descends with the testes into the scrotal stack it also facilitates movement of the testis within the scrotum the excuse me the testes generally descend into the scrotum around the seventh month of fetal development if they don't it's called cryptorquidism and this can involve either one test or both so up here is where the testicles form and then they're going to slowly move down into the scrotal sat generally about four to six weeks before birth and some little boys they don't and if they don't or if they do and they keep moving back up into the abdomen they can be the places where you can find these undescended testicles would be most often between the groin and the scrotum but it can also be up in the abdomen it can also come down into the femoral region and if that happens this is going to be too high a temperature for the sperm to develop normally so what a doctor will have to do is make a slit in the scrotal sack pull that test testicle down into the sack and sort of tack it in place surgically if they don't do that and there's untreated bilateral crypto organism the guy can be sterile and there's also greater risk of testicular cancer crypto organism happens in about three percent of full term and about 30 percent of premature infants most cases they'll just descend spontaneously during the first year life but if they don't then surgery is necessary in the testes we have the sustentacular or sertoli cells as well as lydex cells which are also called interstitial endocrinocytes the sustantacular cells are sort of like nurse cells their job is to to nurse the sperm cells to help them mature to nourish them they also mediate the effects of testosterone as well as follicle stimulating hormone they phagocytize the excess cytoplasm of the spermatids so when they go from being secondary spermatocytes into spermatids they have to and ultimately sperm cells they have to become smaller and look less like cells and more like what we recognize as looking like sperm they also decide when the sperm are mature when they can be released into the lumen so that they can be then transported through the straight tubule and they secrete some initial fluid for sperm transport as well as the hormone inhibin which inhibits it slows down sperm production lighted cells are the cells that secrete testosterone and here you can see these puzzle piece looking cells called the sertoli cells they're connected through tight junctions that form the blood testis barrier this would be the lumen of a seminiferous tubule and then the light egg cells are found outside of the seminiferous tubules and this is where this is lighting it's lydig this is where testosterone is is produced and this is showing the exact same thing um a histological section showing the exact same thing here we have the connective tissue and that's where you find the lighting cells or the interstitial endocrinocytes and then the sertoli cells are found within the seminiferous tubules themselves the goals for lecture one are describe the function and location of the following region um of the male reproductive system the cremaster muscle the dartos muscle the testes the sustentacular or sertoli cells interstitial endocrinocytes the lighting cells the tunica alberginia the tunica vaginalis the wraith the spermatic cord what is the blood testis barrier define kryptorquidism and what are the consequences of the untreated crypt organism