Department of Physiology, Faculty of Medicine, Masaryk University, Brno1 Physiology of reproductive system Organization and regulation of reproductive function. Male reproductive system. Female reproductive system – ovulatory cycle. Compendium of Physiology – autumn 2020 Tibor Stračina Compendium of Physiology2 The presentation is copyrighted work created by employees of Masaryk University. Any unauthorised reproduction or distribution of the presentation or individual slides is against the law. Compendium of Physiology3 Reproduction ̶ High investment, low-volume reproduction stategy ̶ Sexual reproduction Compendium of Physiology4 Differentiation of the reproductive system ̶ Genetic determination (XX vs. XY) ̶ AMH (+ T) Compendium of Physiology5 Puberty ̶ Onset (GnRH) ̶ Men: ̶ adrenarche ̶ Women: ̶ Pubarche ̶ Telarche ̶ Menarche Compendium of Physiology6 MEN Differences in the reproductive function WOMEN ̶ T release – also prenatal + perinatal ̶ Fertile age longer - onset of puberty, andropause) ̶ Non-cyclic hormonal changes ̶ No release of the gonadal hormones before puberty ̶ Fertil age shorter - onset of puberty, menopause) ̶ Cyclic hormonal changes Compendium of Physiology7 MEN Differences in the reproductive function WOMEN ̶ T release – prenatal + perinatal ̶ Fertil age longer - onset of puberty, andropause) ̶ Non-cyclic hormonal changes ̶ No release of the gonadal hormones before puberty ̶ Fertil age shorter - onset of puberty, menopause) ̶ Cyclic hormonal changes Common characteristics: • Postnatal maturation of reproductive system (both structural and functional) • Regulatory axis: hypothalamus – hypophysis – gonads Compendium of Physiology8 Regulatory axis Hypothalamus Hypophysis Gonads https://studentconsult.inkling .com/read/boron-medical- physiology-3e/chapter- 47/figure-47-2 Compendium of Physiology9 Regulation of sex hormone release Hypotalamus Hypofýza Gonády Hormone Regulation Autocrine Paracrine Endocrine GnRH GnRH I (-) GnRH II (+), IGF-I (+), kisspeptin (+) testosterone (-), estrogens (-), progesterone (-), norepinephrine (+), dynorfine (-), leptin (+) FSH - activin (+), follistatin (-) GnRH (+), estrogens (-), progesterone (-), activin (+) inhibins (-) LH - activin (+), follistatin (-) GnRH (+), testosterone (-), estrogens (-), progesterone (-) Testosterone - IGF-I (+), GH (+), TGF-β (-) LH (+) Estrogens - - FSH (+), LH (+) Progesterone - - LH (+) Adopted from: NIEDERBERGER, Craig S., ed. An introduction to male reproductive medicine. Cambridge: Cambridge University Press, 2011. Compendium of Physiology10 MEN Function of FSH and LH WOMEN FSH ̶ Spermatogenesis (Sertoli cells) LH ̶ Intratesticular synthesis of testosterone (Leydig cells) FSH ̶ Maturation of follicular cells ̶ Synthesis of estradiol ̶ Upregulation of LH receptors (preovulatory) ̶ Selection of dominant follicle ̶ Recruitment of follicles for the next cycle LH ̶ Estrogens synthesis (theca cells) ̶ Maturation of oocyte (preovulatory) ̶ Ovulation (rupture of the follicle) ̶ Luteinisation of the follicle (development of the corpus luteum) Compendium of Physiology11 Gonadal steroid hormones: MEN ̶ Testes ̶ Leydig cells (LH) ̶ testosterone ̶ Sertoli cells (FSH) ̶ ABP ̶ p450 aromatase (T→E) ̶ inhibin ̶ growth factors https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-55/figure-54-4 Compendium of Physiology12 Testosterone ̶ Development of male secondary sex characteristics ̶ growth of (male) genitals ̶ growth of prostate ̶ body hair growth ̶ voice deepening ̶ musculoskeletal development ̶ Spermatogenesis ̶ Increase of libido ̶ Changes in behaviour ̶ Erythropoiesis, thrombopoiesis and immune functions are also directly affected Compendium of Physiology13 Spermatogenesis, semen https://studentconsult.inkling.co m/read/boron-medical- physiology-3e/chapter- 54/figure-54-8 Spermiogram (Normal parameter values for semen) Volume of ejaculate 2-6 mL Viscosity liquefaction in 1 h pH 7-8 Sperm cell count more than 20 mil./mL more than 20 mil. in total Viability min. 75% Motility min. 50% (25%) Morphology min. 60% (30%) Compendium of Physiology14 Gonadal steroid hormones: WOMEN ̶ Ovaries ̶ Theca cells (LH) ̶ progesterone, (testosterone) ̶ Granulosa (folicullar) cells (FSH, LH) ̶ progesterone, estradiol https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-55/figure-55-9 Compendium of Physiology15 Estrogens (Oestrogens) ̶ Development of female secondary sex characteristics ̶ enlargement of breasts (+ growth of ducts) ̶ distribution of body fat in hips, thighs, gluteal area, and breasts ̶ musculoskeletal development – widening of hips ̶ growth of genitals ̶ Folliculogenesis, uterine cycle ̶ Increase uterine growth (proteosysthesis) and vaginal wall thickness ̶ Increase of motility in tubes and uterus ̶ Increase of libido, changes in behaviour ̶ Effects on bone resorption, cardiovascular and immune system Compendium of Physiology16 Progesterone ̶ „Hormone of pregnancy“ ̶ Increase of motility in fallopian tubes ̶ Decrease of motility in uterus ̶ Transformation of endometrium – secretion of endometrial glands ̶ Brest development – lobuloalveolar growth ̶ Overall retention of water (in co-operation with estrogens) ̶ Changes in behaviour Compendium of Physiology17 Ovarian cycle ̶ Development of matured oocyte ̶ Cyclic changes of hormonal levels ̶ 3 phases: follicular, ovulation, luteal ̶ Circa 28 days Compendium of Physiology18 Draw hormonal profile of ovarian cycle ̶ Estrogens, progesterone ̶ FSH, LH ̶ GnRH Compendium of Physiology19 Ovarian cycle https://studentconsult.inklin g.com/read/boron-medical- physiology-3e/chapter- 55/figure-55-6 Compendium of Physiology20 Uterine (Endometrial) cycle ̶ Cyclic changes of endometrium ̶ 3 phases: menstrual (menses), proliferative, secretory ̶ Cyclic changes of genitals and breasts ̶ And other somatic changes Compendium of Physiology21 Uterine cycle https://studentconsult.inklin g.com/read/boron-medical- physiology-3e/chapter- 55/figure-55-11 Compendium of Physiology22 https://studentconsult.inklin g.com/read/boron-medical- physiology-3e/chapter- 55/figure-55-6 https://studentconsult.inklin g.com/read/boron-medical- physiology-3e/chapter- 55/figure-55-11 Compendium of Physiology23 Corpus luteum, corpus luteum graviditatis ̶ Follicular cells after ovulation → corpus haemmorhagicum ̶ LH ̶ corpus haemmorhagicum → corpus luteum (c. l.) ̶ decrease of LH + no hCG → involution of c. l. ̶ decrease of LH + hCG → proliferation of CL → c. l. graviditatis Compendium of Physiology24 The presentation is copyrighted work created by employees of Masaryk University. Any unauthorised reproduction or distribution of the presentation or individual slides is against the law.