BIOL 320 1st Edition Final Exam Study Guide Lectures 24 25 Lecture 24 Male Reproduction Understand the structures and functions of the male reproductive system Know how sperm is developed Understand the hormonal control and the developmental aspects Structures Testes contain the seminiferous tubules produce sperm surrounded by interstitial cells that produce testosterone Epididymis absorb testicular fluid pass nutrients to sperm Scrotum thermoregulation keeps tests 3 C than body core temperature Vas deferens Urethra carries both urine and semen at different times Seminal vesicle Prostate gland partially activates sperm Bulbourethral gland secretes mucous prior to ejaculation to clear any traces of acidic urine Penis sperm delivery Spermatogenesis Meiosis of diploid stem cell 46 chromosomes to haploid 23 chromosome mature spermatozoa Stem cells spermatogonia undergo mitosis spermatocytes undergo meiosis Haploid maturing cells spermatids Mature gamete spermatozoon Stage occur at specific locations in Sertoli cells Mature spermatozoa travel from seminiferous tubules to epididymis by peristalsis Two Phases o Spermiogenesis o Meiosis Two Compartments o Adluminal compartment o Basal compartment Hormonal Control LH Interstitial Cells Testosterone Blood FSH Sertoli Cells Spermatogenesis with Testosterone produced by interstitial cells Also stimulate male secondary sexual characteristics o Hair muscle mas vocal chords behavior Adam s apple Developmental Aspects Week 5 Wolffian ducts form internally primordial germ cells populate these spermatogonia Week 7 under influence of testosterone male structures form internally testes near kidneys externally labioscrotal swelling scrotum genital tubercle penis grows around urethra Month 8 surge of testosterone stimulate testes descent into scrotum cryptorchid failure of one or both testes to descend Puberty organs reach full size function hair beard armpit growth muscle development voice drops Adam s apple Lecture 25 Female Reproduction Understand the structures and functions of the female reproductive system Know the ovarian and menstrual cycles Understand the hormonal control and the developmental aspects Structures Ovary produce gametes sex hormones Uterine tubes receive ovulated oocytes site of fertilization carries oocyte to uterus Uterus highly vascularized site for implantation of zygote Vagina passage way for birth menstrual flow and organ of copulation Oogenesis Definition production of female gametes via meiosis In the fetal period 1 Oogonia multiply by mitosis 2 Primordial follicles appear primary oocytes 3 Primary oocytes start meiosis I but stall in prophase I At and after puberty 1 One primary oocyte 2 haploid cells polar body secondary oocyte 2 Secondary oocyte arrests in metaphase II 3 If penetrated by sperm then the secondary oocytes complete meiosis II large ovum second polar body Ovarian Cycle Definition monthly series of events associated with maturation of the egg Two Phases o Follicular phase steps 1 6 1 Thecal granulosa cells produce estrogens 2 Zona pellucida forms around oocyte 3 Antrum formation occurs secondary follicle secondary follicle Graafian follicle 4 Antrum enlarges corona radiata forms 5 Follicles bulges from surface of ovary 6 Primary oocyte completes meiosis I o Luteal phase steps 7 9 days 14 28 1 Ruptured follicle collapses 2 Granulosa cells enlarge with thecal cells corpus luteum 3 Corpus luteum secretes estrogen progesterone 4 If no pregnancy corpus luteum last 10 days If fertilization occurs corpus luteum last 3 months produce hormones to maintain endometrium until placenta takes over 5 Corpus albicans scar of degenerated corpus luteum o Ovulation Graafian follicle burst releasing oocyte mittelschmerz twinge felt by some women at ovulation 1 2 ovulation more than primary oocytes fraternal twins o Establishment during childhood ovaries grow secrete low estrogen inhibit release of GnRH from ventral hypothalamus During puberty GnRH released FSH LH act on ovaries Therefore adult cyclical pattern o Hormone Interactions Day 1 GnRH stimulate release of FSH LH stimulate follicle growth maturation low estrogen levels Before day 14 estrogen levels rising inhibit FSH LH anterior pituitary accumulates them Day 14 high levels of estrogen positive feedback on LH FSH surge of LH FSH formation of secondary oocyte metaphase II ovulation occurs corpus luteum formed After day 14 corpus luteum produces inhibin estrogen progesterone LH FSH production shuts down Days 26 28 ovarian hormone production declines LH FSH no longer inhibited so cycle starts again Menstrual Cycle Definition cyclical changes in uterine lining in response to ovarian hormones Days 1 5 flow phase all but deepest layers of lining are shed Days 6 14 proliferative phase endometrium rebuilds self Days 15 28 secretory phase getting ready for implantation very vascular glands extend deep into lining If fertilization does not occur 1 Progesterone levels decline 2 Hormonal support of endometrium is gone 3 Spiral arteries kink spasm endometrial cells die 4 Functional layer digests self 5 Spiral arteries constrict then dilate open 6 Sudden rush of blood fractionates capillary beds layer sloughs Hormonal Control Estrogen Progesterone Effects 1 Promote oogenesis follicle growth 2 Anabolic effects on female structures Uterine tubes uterus vagina enlarge become functional Uterus tubes develop motility Vaginal lining thickens external genitalia matures Secondary Sex Characteristics 1 Development promoted by estrogen 2 Breast development 3 Pelvis wider lighter 4 Subcutaneous fat deposition especially breast tissue and hips 5 Axillary pubic hair Developmental Aspects 5th week Mullerian ducts form internally soon primordial germ cells oogonia 8th week female structures forming o In absence of testosterone labioscrotal swelling labia majora genital tubercle clitoris urethral folds labia minora 8th month ovaries descend but are trapped by broad ligament Puberty reproductive organs reach full size function secondary sex characteristics appear menstrual cycle begins As women age ovaries become scarred pitted from many ovulations can lead to fertility problems Menopause ovulation menses stops hormonal support ceases anabolic effects cease reproductive tissue atrophy o Symptoms hot flashes mood swings depression thinning of skin osteoporosis Conception Understand how conception occurs Know what implantation involves and placentation Specifics The ovulated secondary oocyte is