MSCI M131 Lecture 1-5(Unit 1)Outline of Current Lecture I. Male Reproductive Systema. Scrotumb. Testesc. Spermatogenesisd. Duct system and accessory glandse. Infertility, sterility, and erectile disorderCurrent LectureI. Scrotum: a pouch of skin with a thickened fat layer (function – to protect and to maintain the testes at approximately 3 degrees below body temp)II. Testes: originally produced in pelvic cavity, descend around 28th week of pregnancy.A layer of tissue from the pelvic cavity precedes it as the testes descend into the scrotuma. Cryptorchidism- “hidden testes,” refers to a testis that is not in the scrotum – can be in many positions – undescended= body temp= bad spermi. Incidence: 30% in premature males, and 1-3% in newbornsii. Etiology: unknown, but may be related to hormone deficiencyiii. Problems: if left untreated, infertility or sterilityiv. Treatment: often the undescended testes will descend into the scrotum on their own during the first 3 mos. Following birth. If not, orchiopexy (pex- put into position) may be needed to secure the testicle into normal position. (palpate to find position; open area, bring testicle to scrotum and attach it to the scrotum so it doesn’t return to original position)b. Hydrocele: a collection of fluid found anywhere along the length of the processus vaginalis (opening through which the testes descend) i. Etiology: open processus vaginalis (fluid can seep down)ii. Problems: increased scrotum size causes pain and can occasionally block blood flowiii. Treatment: these may be aspirated (drained) but fluid usually reaccumulates – surgery may be needed to close off the open processus vaginalis (when tissues meet together they usually grow together) These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c. Testicular Torsion: a twisting of the spermatic cord which usually causes pain, impairment of blood flow, localized swelling. This may occur in newborn, but most often in young boys (moving, walking, running causes torsion) Older men can have tissue breakdown and there may be swelling of epididymis i. Problems: if torsion has been present for more than 24 hours, the survival of the testicle is doubtful (decreased blood flow)ii. Treatment – with early detection, surgery may be performed to open up the scrotum, untwist the spermatic cord, and secure the testicle to the scrotal wall (must secure or else it will twist again) d. Testicular cancer: although rare (37 cases in 100,000), these rumors represent the most common tumors of men between 20 and 34 years in the US. (was a quiz question!!)i. Etiology unknownii. Problems: pain, infertility due to tissue destruction, and spread of cancerous cells to other organsiii. Treatment: 95% of tumors involve the cells associated with seminiferous tubules. Diagnosis through detection of bumpy surface and biopsy. Treatment can be complicated:1. Following diagnosis, removal of testis and spermatic cord is necessary2. If the cancer has spread, removal of lymph nodes may be needed (organelles responsible for immune-defense, but cancer can be there and spread)3. Radiation therapy and/or chemotherapy may be needed4. Some situations call for combo of theseIII. Spermatogenesis: sequence of events leading to the final production of sperma. Seminiferous tubules: highly coiled tubular structures found within each testis. The wall is comprised of large cells called sustentacular cells, which protect the developing sperm from the body’s immune cells (“blood-testis barrier”). There are multiple sperm in one sustentacular cell. In between the tubules are cells called interstitial cells which produce the male sex hormone testosterone. b. Hormonal regulation: at puberty 2 hormones are released from brain: Interstitial cell stimulating hormone (ICSH) and follicle stimulating hormone (FSH). ICSH stimulates interstitial cells to secrete testosterone, an androgen. FSH stimulates Sertoli cells (sustentacular cells) to produce ABP, androgen binding protein. 1. ABP allows developing sperm to bind to testosterone and spermatogenesis is induced. 2. Testosterone is also responsible for development of secondary sexcharacteristicsIV. Duct system and Accessory glandsa. Epididymis: a 20’ long coiled tube attached to the testicle. It functions to store the immature (nearly motile) sperm (stores large volumes)i. Epididymitis: inflation of the epididymis frequently caused by gonorrheabacterium1. Problems: infection, often infection of penis and prostate gland are often seen with epididymitis 2. Treatment: antibiotics to treat gonorrheab. Ductus (vas) Deferens: an 18” long tubular structure from the epididymis to theprostate – purpose to store mature (motile) spermi. Vasectomy – voluntary sterilization; small section of each ductus deferens near the epididymis is surgically removed and the cut ends are clipped back (usually sutured) – interferes with sperm transport, but neither affects the secretion of testosterone from the interstitial cells not the production of sperm (spermatogenesis continues, sperm reabsorbed) bilateral – on both sides, can do with a single entry; reversal by matching openings and resuturing – chance of pregnancy is 76% after 3 years, 30% after 15 years or morec. Seminal Vesicles: glands that secrete a fluid that contains mostly fructose (sugar). Sperm use as energy source after ejaculation, only lasts 24-48 hrs.; fluid contributes to semen (sperm + fluid)d. Ejaculatory ducts: continuation of duct system inside the prostate. They are formed by the union of the ductus deferens and the ducts of the seminal vesicles. i. Prostatic urethra – tube carries urine, but muscles at the base of the bladder close off during ejaculatione. Prostate: accessory gland located just below bladder. Secretes slightly acidic fluid with contains citric acid (nutrient), seminalplasmin (bacteriocidal – protect from infection in female system), and PSA (prostate specific antigen, an enzyme to help liquefy semen). Fluid goes into prostatic urethra. i. Semen – thick mucus like globs to keep sperm together – PSA will help liquefy it and sperm can swim after entering female system. ii. Test for potential prostate or seminal vesicle problems – digital rectal exam (DRE) – screen, palpate for size, shape, density, growthsiii. Orgasm is a release of hormones from brain; induced