A&P Exam 4 ObjectivesPower Point #1: Male Reproductive System1. Explain the parasympathetic and sympathetic innervations of the male reproductive system and the effects of each.- PNSo stimulates increase in NO (nitrous oxide)o relaxation and vasodilation of arterioleso erectile bodies fill with bloodo this causes erection- SNSo stimulates spinal reflexo contraction of ducts and glandso constriction of bladdero contraction of bulbospongiosus muscleso this causes ejaculation: propulsion of semen from male duct system2. Describe the exocrine and endocrine function of the testes. Example: Sertoli and Leydig cells.- exocrine function: production of mature sperm (spermatogenesis); involves seminiferous epithelium and Sertoli cells- endocrine function: production of androgens (steroidogenesis); involves interstitial compartment and Leydig cells3. Explain, IN DETAIL, the entire process of spermatogenesis as we described in class (what happens in each phase and it’s time frame through the seminiferous epithelium).- spermatogenesis: production of sperm (gametes/spermatozoa) that takes place in seminiferous tubules of testeso begins at about age 14 and makes ~4 million sperm per dayo Proliferative Phase Type A dark (Ad) spermatogonia (dense chromatin) Type A pale (Ap) spermatogonia (less dense chromatin) Type B Ad gives rise to Ap as well as generates more Ad for future generations of sperm Ap gives rise to Bo Meiotic Phase Meiosis I: type B divides by mitosis to primary spermatocytes and replicated chromosomes seek out partner after: each daughter cell has 2 copies and number of chromosomes is cut in half (from 46-23 chromosomes) Meiosis II: further division of cells, but chromosome number stays the sameo Spermiogenic Phase (differentiation of spermatid into sperm) Golgi Phase: tail filament phase Cap Phase: head cap appears from acrosomal granule Acrosomal Phase: nucleus and head cap elongate, and acrosomal granule differentiates to form acrosome (acrosome eats away at egg = acrosomal reaction) Maturation Phase: cell completes differentiation to become a mature sperm - Seminiferous Epithelium o Cells 1st cycle: Type A gives rise to Type B 2nd cycle: primary spermatocytes form 3rd cycle: spermatids appear 4th cycle: spermiogenesis completed and spermiation beginso Cycles spermatogonia initiate new cycle every 16 days, so 64 days for all four cycles to complete once sperm is released into lumen, another 10 days are required for movement to epididymus (total of 74 days) sperm are stored in the epididymus 4. Explain the hormonal control of spermatogenesis as it relates to FSH and LH.- FSH and testosterone are both required for regulation of spermatogenesis- FSH binds to receptors in Sertoli cells to help initiate spermatogenesis, which also causes an increase in ABP- FSH also causes an increase in number of LH (leutenizing hormone) in Leydig cells, causing testosterone production to increase- this maintains spermatogenesis5. Explain the role of the epididymis and where the ejaculate comes from.- flow of sperm: epididymus ductus (vas) deferns ejaculatory duct urethra - epididymus: stores mature spermo sperm migration through epididymus takes about 10-16 dayso takes about 90 days (time include spermatogenesis and migration) for mature sperm to appear in ejaculateo sperm mature and acquire the capacity for motility in epdidymus - Seminal plasma and semeno seminal plasma: secretions from sex accessory glands (seminal vesicles, prostate, Cowper’s/ bulbourethral glands, ampulla of vas deferens)o semen: combination of seminal plasma and spermo order of ejaculation: Cowper gland ampulla of epididymus (holding sperm) seminal vesicles o sperm may be present in pre-ejaculatory fluid, but small amounto Cowper’s gland: 5% of ejaculate may contain small amount of sperm clear fluid, rich in mucoproteins lubricates distal urethrao Prostate gland: 15-30% of ejaculate contains citric acid, acid phosphatase, calcium, and zinc liquefies ejaculate PSA (prostate-specific antigen) helps activate sperm motility no sperm comes from this portiono Seminal vesicles: 45-80% of ejaculate rich in fructose and prostaglandins prostaglandins cause smooth muscle relaxation and contraction to propel ejaculate contains enzymes that cause coagulation of ejaculate absence of fructose used to diagnose absence of vas deferens (in epididymus) infertility*** Tanner stages (5 stages) : stages of sexual maturity in males *** Power Point #2: Female Reproductive System1. Explain the time frame of oogenesis.- oogenesis: takes place during the fetal stage of life, and is the process of producing female sex cellso oogonia: stem cells- oogonia divided by mitosis are transferred into primary oocytes- primary oocytes then begin meiosis, but do not complete it- oogonia peak at 20 weeks, then undergo meiosis, then the number of oogonia greatly diminishes o women will have all the eggs she need by 20 weeks in mother’s womb- oogenesis begins at 6-8 weeks, reaching 6-7 million oogonia (primordial follicles) by 16-20 weeks (max oogonial content of gonad)- store of oocytes finally becomes depleted about 50 years later2. DETAIL the ovarian cycle. Explain each phase, time frames, estrogen production, hormone level fluctuation, body temperature, the hypothalamic pituitary axis stimulation of these hormones, and explain all graphs in detail (understand all graphs, this is the bulk of this objective and presentation).- Establishing the ovarian cycleo during childhood, ovaries grow and secrete small amounts of estrogen that inhibit the hypothalamic release of GnRH (gonadotrophin-releasing hormone)o as puberty nears, GnRH is released from the hypothalamus, stimulating release of FSH and LH from pituitary, and these act on the ovary FSH: causes maturation and maintenance of follicles LH: surges at ovulation (day 14) and forms corpus luteumo fatty tissue increase is also associated with puberty, which results in an increase in leptin (which also influence the hypothalamus)o these events will continue until menarche (first menstrual cycle a woman has)- Follicular phase: period of follicle growth (days 1-14)o time frame may vary (length of cycles can vary from 21-40 days, depending on the woman)o FSH (follicle-stimulating hormone) develops about 20 follicles at beginning of each ovarian cycle,
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