(Chapters 17, 18, 19 (pages 438-449), 16 (pages 376-387))

Introduction

• Hypothalamo-hypophyseal gonad axis.
• Major hormones, peptides and steroids.
• Gonadal cells.
• Viviparous and oviparous modes of reproduction.
• Modifications of acessory organs and reproductive tracts.

Male Reproductive Physiology

• A simplier system compared to female.
• Testicular structure and general anatomy of the male system.
  • Leydig cells, Sertoli cells, and ductal systems.
  • Tubular and lobular testis in vertebrates.
  • Spermatogenesis, spermiation and sperm capacitation.
  • Blood testis barrier.
• Steroidogenesis and androgen metabolism
  • Steroid synthesis pathway from cholesterol. LDL uptake.
  • delta 4 and delta 5 pathways.
  • Testosterone in blood and binding proteins.
  • Degradation and excretion of androgens.
  • Testicular sites of androgen productrion (role of Leydig cells and Sertoli cells).
• Endocrine regulation of gametogenesis and steroidogenesis
  • Role of pituitary gonadotropins.
  • Testicular negative feedback actions on pituitary and hypothalamus.
  • Importance of feedback.
  • Differential actions of FSH and LH. Their interactions.
  • Influences of PRL and GH on testicular steroidogenesis.
  • Importance of local production of testosterone and testosterone binding proteins.

Mechanisms of Androgen Action

• General scheme of steroid hormone action.
  • Interaction with intracellular receptors.
  • Steroid receptor structures.
  • Receptor associated proteins.
  • Nuclear action and its activation.
  • Other requirements and mechanisms?
• Role of androgen metabolites in androgen action.
• Examples of physiological actions of androgens
  • Role of androgen in prepubertal stages.
    • Genital ducts development
    • Brain development
    • External genitalia.
  • Role of androgens in pubertal and adult stages.
    • Gonads and reproductive tract maturation
    • Anabolic effects
    • CNS effects
    • Secondary sexual characteristics.

Female Reproductive Physiology

• Cyclic changes.
• Ovarian structure and female reproductive tract - typical mammalian.
  • Germinal epithelium and follicular maturation.
  • Fate of follicles, selection of follicles, why multiple follicles.
  • Follicular cell layers - theca and granulosa
  • Corpus hemorrhagium, corpus luteum, corpus albicans.
• Variations of ovarian structures among vertebrates
• Hormonal regulation of ovarian cycle
  • Estrus vs. menstrual
  • Endocrine changes in follicular phase
    • Role of FSH and LH
    • Two cell theory in ovarian steroidogenesis
    • Relative balance of E2 and P4.
    • Role of steroids on vaginal and uterine growth
    • Role of gonadal peptides - inhibin, activin, follistatin
    • Negative feedback regulation of pituitary.
    • Positive feedback regulation.
    • Role of surge inhibitory factor?
    • Ovulation and follicular rupture. Actions of local hormones.
    • Spontaneous vs. induced ovulators
  • Hormonal changes in luteal phase
    • Development of the corpus luteum and its hormonal control
    • Hormonal conctrol of corpus luteum secretion
    • Function and role of corpus luteum secretion (steroids and petides)
    • Changes in P4 to E2 ratio and its consequence.
    • Final maturation and development of the uterine wall
    • Preparation for implantation
  • Hormonal changes in menstrual phase
    • Consequence of limited corpus luteum "functional life-span"
    • Changes in P4 to E2 ratio and its consequence
    • Uterine changes
    • Changes in feedback regulation status and start of new cycle.
• Hormonal changes upon implantation and pregnancy
  • Fertilization, blastomeres and blastula, and implantation
  • Decidua formation
  • Syncytiotrophoblasts and cytotrophoblasts
  • Corpus luteum rescue
  • Role of LH, hCG and progesterone in maintaining pregnancy
  • Development steroid synthetic capacity in the placenta and fetal adrenal.
  • Activin and inhibin production during pregnancy and their function.
• Hormonal events during late pregnancy and parturition
  • Changes in E2 and P4 ratio and consequences.
  • Roles of other placental hormones (e.g., placental lactogen)
  • Relaxin production and role.
  • Changes in E2 receptor number in uterus, priming effects.
  • Oxytocin and prostaglandin production during labour.

Examples of other actions of ovarian steroids

• External yolk formation and vitellogenesis.
• Actions on oviduct.
• Sexual behaviour.
• Secondary sexual characteristics
• Pheromones