Biological Sex and Gender

  • Variation in biological sex traits is normal across levels of sex development.
  • Gender is a social construct, separate from genetic sex.
  • The SRY gene on the Y chromosome leads to male development when present; absence results in female development.
  • Intersex conditions arise from discrepancies between genotype and external genitalia.

Sexual Maturation

  • Puberty begins in adolescence, activating reproductive organs and characteristics.
  • Gonadotropin-releasing hormone (GnRH) leads to the secretion of FSH and LH.
  • Mitosis and meiosis maturation of gametes reviewed in future lectures.

Female Anatomy Functions

  • Produce sex hormones and functional gametes.
  • Protect and support embryo; nourish infant.
  • External genitalia: vulva and mammary glands; internal: vagina, uterus, uterine tubes, ovaries.

Lactation Process

  • Stimulated by suckling; prolactin released to produce milk.
  • Oxytocin facilitates milk release from mammary glands.
  • Positive feedback until suckling ends.

Uterus Function

  • Encloses and supports fetus; includes cervix, body, fundus, and different layers (perimetrium, myometrium, endometrium).

Ovarian Cycle Overview

  • Four phases: Follicular (days 1-13), Ovulation (day 14), Luteal (days 15-28).
  • Follicle development and hormone secretion regulated by FSH and LH.

Folliculogenesis

  • Involves primordial follicles maturing into primary, secondary, and antral follicles.
  • Inhibin and estrogen produced to regulate development.

Oogenesis Timeline

  • Starts before birth, resumes at puberty, ends at menopause.
  • Involves stages from oogonia to primary oocytes and further to ovum and polar bodies.

Fertilization Process

  • Occurs typically in the ampulla; involves penetration and fusion of sperm and oocyte.
  • Secondary oocyte completes meiosis upon fertilization to form zygote.

Cleavage and Implantation

  • Zygote undergoes mitotic divisions leading to morula and then to blastocyst stages.
  • Implantation occurs around day 7, with the blastocyst attaching to endometrium.

Hormonal Control

  • GnRH triggers FSH and LH, influencing follicle and corpus luteum development, and regulating menstrual cycles.

Uterine Cycle

  • Three phases: Menstrual (shedding endometrium), Proliferative (building lining), Secretory (further development influenced by hormones).