Chapter 8 Reproduction (Part I) PDF

SB0014 Cell Diversity, Reproduction, Ecology & Development Reproduction (Part I) Dr Farah Nadia Omar [email protected] 012-219 5145 COURSE OUTLINE 8.1 Human reproduction systems 8.2 Hormonal control 8.3 Ovarian/ Menstrual Cycle At the end of this chapter, studen...

SB0014 Cell Diversity, Reproduction, Ecology & Development Reproduction (Part I) Dr Farah Nadia Omar [email protected] 012-219 5145 COURSE OUTLINE 8.1 Human reproduction systems 8.2 Hormonal control 8.3 Ovarian/ Menstrual Cycle At the end of this chapter, student should be able to: Describe about human reproductive system Describe roles of hormones in human reproductive system Explain ovarian & uterine cycle COURSE OUTLINE 8.1 Human reproduction systems 8.2 Hormonal control 8.3 Ovarian/ Menstrual Cycle At the end of this chapter, student should be able to: Describe about human reproductive system Describe roles of hormones in human reproductive system Explain ovarian & uterine cycle Disclaimer: All images, videos and information presented are solely for educational purposes. Thank you. Male Reproductive System A complex network of organs and structures responsible for producing and delivering sperm for reproduction. Side view Key components: Testis, Vas Deferens, Prostate, Penis, Urethra, Scrotum, Epididymis Front view To transports mature sperm to urethra for ejaculation Make up to 80% of ejaculatory fluid Transport sperm from the vas deferens to the 1. Delivering semen urethra into the female A temporary storage site reproduction organ for feces until 2.Transporting urine defecation out of the body Adds additional fluid to ejaculatory fluid Carries pee from your bladder outside of To carries and stores the produced sperm cells your body To produce testosterone and produce sperm To protects the testicles Female Reproductive System A complex structure responsible for various functions related to reproduction, sexual health, and hormone regulation Side view Key components: Ovaries, Fimbriae, Fallopian Tubes, Uterus, Cervix, Vagina Front view  1. Pathways for ovum to travel from ovaries to uterus 2. Site for fertilization when Site for the implantation an ovum meets sperm of a fertilized egg, allowing for the development of the embryo into a fetus. Sweeping matured ovum from ovaries to the fallopian tubes Narrow portion of the uterus that connects the uterus to the vagina small, oval-shaped glands that produce ovum and hormone 1. Fibromuscular canal that connects the external genitalia to the cervix, serving as the birth canal during delivery 2. Passageway for menstrual fluid to exit the body Gametogenesis A biological process through which specialized sex cells, or gametes, are formed in organisms that reproduce sexually Spermatogenesis Occurs in the testes, involves the transformation of spermatogonia (diploid cells) into mature spermatozoa through multiple stages of meiotic division. Oogenesis Occurs in the ovaries and begins during fetal development, where oogonia (diploid cells) multiply and develop into primary oocytes Spermatogenesis  Occurs inside the seminiferous tubules, which is a convoluted cluster of tubes located inside the testes.  Duration approximately 64 to 74 days, with continuous production from puberty throughout male’s reproductive life.  Involves 3 stages: i. Mitosis (spermatogonia  two spermatocytes) ii. Meiosis (spermatocytes  spermatids) iii. Spermiogenesis (spermatids  sperms) Copyright © 2004 Pearson Education, Inc. Pathway of Sperm Seminiferous Epididymis tubules Ejaculatory Vas deferens duct Urethra  Oogenesis  Occurs inside the ovaries, outermost epithelial layer.  Begin very early in female’s life. From embryonic stage to foetal stage to puberty until reach menopause stage.  Key Stages of Oogenesis: 1. Prenatal Development: Primordial germ cells  oogonia. 2. Formation of Primary Oocytes: Oogonia Primary oocytes (Meiosis I but arrested in prophase I until puberty). 3. Puberty and Follicular Development: Primary oocytes  ovarian follicles secondary oocyte + smaller polar body. 4. Ovulation: Secondary oocyte is released & arrested in metaphase II of meiosis II, will complete the meiosis II if fertilization occurs. 5. Fertilization: If a sperm fertilizes the secondary oocyte, it completes meiosis II, producing a mature ovum and a second polar body. Copyright © 2016 Pearson Education, Inc. https://www.youtube.com/watch?v=Msrym4oGVSk http://www.brainkart.com/article/Oogenesis-and- Fertilization---Female-Reproductive-System_21991/ Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings  Has three sections – head, mid-piece and tail  Head region has three structures – nucleus, acrosome cap and centrioles o The haploid nucleus contains the paternal DNA o The acrosome cap contains hydrolytic enzymes to penetrate the jelly coat of the egg o The centrioles are needed by a zygote in order to divide  Mid-piece has many mitochondria to provide the energy (ATP) needed for the tail to move  Tail (flagellum) is a microtubule structure called the axoneme, which bends to facilitate movement https://old-ib.bioninja.com.au/higher-level/topic-11-animal-physiology/114-sexual-reproduction/egg-and-sperm.html  A typical egg cell is surrounded by two layers – the zone pellucida (jelly coat) and corona radiata o Zona pellucida: a barrier to sperm entry o Corona radiata: provide support & nutrients  Cortical granules will release their contents upon fertilisation to prevent polyspermy  Although diagrams of egg cells commonly include a haploid nucleus, no nucleus will form within the egg until after fertilisation has occurred (the egg cell is arrested in metaphase II until it becomes fertilised by a sperm) https://old-ib.bioninja.com.au/higher-level/topic-11-animal-physiology/114-sexual-reproduction/egg-and-sperm.html Spermatogenesis vs Oogenesis https://imat.entermedschool.com/t/difference-between-spermatogenesis-and-oogenesis/5364 Let’s recap! a) What is the name of gametogenesis process in male and female? (2M) Male: Spermatogenesis (1M) Female : Oogenesis (1M) b) State the specific location for each process in (a) to occur. (2M) Spermatogenesis : seminiferous tubule/ Testis (1m) Oogenesis : Ovary (1m) c) What is the term used for immature sperm? (1M) Spermatid (1m) d) What happen to secondary oocyte if: There is penetration of a sperm (2M) ∙ Secondary oocyte will complete its meiosis II (1m) ∙ Produce ovum and second body polar (1m) There is no penetration of sperm (1M) Secondary oocyte will degenerate (1m) COURSE OUTLINE 8.1 Human reproduction systems 8.2 Hormonal control 8.3 Ovarian/ Menstrual Cycle At the end of this chapter, student should be able to: Describe about human reproductive system Describe roles of hormones in human reproductive system Explain ovarian & uterine cycle  Hormone Regulations in Male  Involve: Hypothalamus, pituitary gland, and testes.  3 key hormones: gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).  GnRH: Produced by hypothalamus, it stimulates the pituitary gland to release FSH and LH.  FSH: Produced by pituitary gland and acts on Sertoli cells, it stimulates maturation of sperm cells, concentrate testosterone in the seminiferous tubule. Regulated by inhibin that give –ve feedback when sperm count too high.  LH: Produced by pituitary gland, it stimulates testes to produce testosterone.  High levels of testosterone and inhibin give –ve feedback on hypothalamus & pituitary gland, inhibiting the release of GnRH, FSH, and LH https://www.brainkart.com/article/Physiology-of-Male-Reproduction_21983/ https://www.brainkart.com/article/Physiology-of-Male-Reproduction_21983/  Hormone Regulations in Female  Involve: Hypothalamus, pituitary gland, and ovaries.  Key hormones: gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), estrogen and progesterone.  GnRH: Produced by hypothalamus, it stimulates the pituitary gland to release FSH and LH.  FSH: Produced by pituitary gland, it stimulates maturation of eggs. Encourage production inhibin that give –ve feedback to regulate its own levels.  LH: Produced by pituitary gland, it stimulates ovulation & formation corpus luteum.  Estrogen: Produced by developing follicles in the ovaries, stimulates menstrual cycle & promotes secondary sexual characteristics  Progesterone: Secreted by the corpus luteum, helps maintain the uterine lining for pregnancy https://flexbooks.ck12.org/cbook/ck-12-advanced- biology/section/17.82/primary/lesson/the-menstrual-cycle-advanced-bio- adv/ Females https://www.brainkart.com/article/Physiology-of-Male-Reproduction_21983/ COURSE OUTLINE 8.1 Human reproduction systems 8.2 Hormonal control 8.3 Ovarian Cycle & Uterine Cycle At the end of this chapter, student should be able to: Describe about human reproductive system Describe roles of hormones in human reproductive system Explain ovarian & uterine cycle  GnRH FSH Estrogen Gonadotrophin Follicle stimulating hormone Progesterone releasing hormone LH Luteinizing hormone (regulate phases of (stimulate release uterine cycle AND of FSH & LH) (regulate phases of ovarian influence release cycle) GnRH/FSH/LH)  The ovarian cycle occurs in the cortex of the OVARIAN ovary The ovarian cycle prepares the egg for CYCLE fertilization and reproduction  Describes changes that occur in the follicles of the ovary UTERINE  The uterine cycle occurs in the uterus  The uterine cycle prepares the uterine wall CYCLE to receive a fertilized egg.  Describes changes in the endometrial lining of the uterus  OVARIAN MENSTRUAL CYCLE CYCLE 1. Follicular Phase (Day 1- 14) 1. Menstrual Phase (Day 1- 5) FSH  Follicles (contain eggs) develop Shed inner linings of endometrium and release estrogen due to drop progesterone from dying corpus luteum 2. Ovulation (Day 14) Rising estrogen triggers LH surge 2. Proliferative Phase (Day 6-14) LH surge triggers ovulation (release egg Regrow endometrium due to rise in from follicle) estrogen from follicular phase 3. Luteal Phase (Day 14-28) 3. Secretory Phase (Day 14-28) Follicle becomes corpus luteum Endometrium secretes nutrient (to Corpus luteum release progesterone (and support growing embryo) due to rise estrogen) in progesterone from luteal phase No embryo  No corpus luteum  Low progesterone  Induce menstrual phase  Tracking Menstrual Day 1. Calculate manually using calendar 2. Use commercial apps Tracking Menstrual & Tracking Ovulation Day Ovulation 1. Calculate manually using calendar 2. Use commercial apps 3. Basal Body Temperature (BBT) Method 4. Cervical Mucus Method 5. Ovulation Predictor Kits (OPKs)  Birth Control Options There is no 100% guarantee on the effectiveness of these options except sterilization methods. The egg is retrieved & fertilized with sperm. The fertilized egg is kept in the petri dish for 3-5 days to form an embryo. Once the embryo is formed it is implanted back to the woman’s uterus. The sperm is implanted into the uterus. The women are given fertility drugs so that egg production is increased. One or more egg is removed from a woman’s body. The mature egg is taken and injected with healthy sperm. The egg develops and then transferred back to the woman’s body. The egg is fertilized inside the fallopian tube https://sofatinfertility.com/news/assisted-reproductive-technology-treatments-for-infertility/  Let’s recap! a) State the functions of FSH, LH, estrogen and progesterone hormones in female reproductive cycle (4M) FSH - stimulate the follicle to burst / release the secondary oocyte. (1m) LH – stimulate ovulation (1m) Progesterone – maintains the thickening of the endometrium wall (1m) Estrogen- regulate the menstrual cycle/ controlling the growth of the uterine lining during the first part of the cycle (1m) b) Name 1 permanent contraceptive method for male (1M) Vasectomy (1M) Thank You! Feel free to ask questions!