topic 12 pt 2

• What hormone is released from the hypothalamus at puberty?

  Gonadotropin Releasing Hormone (GnRH)

  
• What is the effect of GnRH on the anterior pituitary gland?

  It stimulates the secretion of LH and FSH.

  
• What hormones do the ovaries release?

  Estrogen and progesterone

  
• What are the roles of estrogen and progesterone in the female body?

  They are responsible for maturation of mammary glands, genitalia, secondary sex characteristics, sexual behavior, and the uterine cycle.
• What are the steps involved in the hormonal regulation of the ovarian cycle?

  1. Rising GnRH stimulates FSH and LH production.
  2. FSH stimulates follicle maturation; LH stimulates estrogen production.
  3. Estrogen exerts negative feedback on FSH and LH.
  4. High estrogen levels trigger LH and FSH surge.
  5. LH surge causes ovulation and corpus luteum formation.
  6. Rising progesterone and estrogen levels inhibit FSH and LH.
  7. Low LH levels lead to corpus luteum degeneration and menstruation.

  
• What is the average duration of the reproductive cycle?

  28 days
• What occurs during the follicular phase of the ovarian cycle?

  It is the period of follicle growth and maturation before ovulation.

  
• When does ovulation typically occur in the cycle?

  Day 14
• What happens during the luteal phase of the ovarian cycle?

  It is the period of corpus luteum activity after ovulation.

  
• What is the fate of the corpus luteum if fertilization occurs?

  It persists and produces hormones until the placenta takes over.

  
• What occurs during menstruation?

  The functional layer of the endometrium sloughs off due to low estrogen and progesterone levels.

  
• What are the phases of the uterine cycle?

  1. Menses (day 1-5): Sloughing off of the functional layer.
  2. Proliferative phase (day 5-14): Epithelial cells proliferate in response to estrogen.
  3. Secretory phase (day 14-28): Hypertrophy of endometrial layers in response to progesterone.

  
• What hormone stimulates the production of milk in mammary glands during pregnancy?

  Prolactin
• What is the role of oxytocin during childbirth?

  It causes contraction of uterine smooth muscle.
• Where does fertilization typically occur?

  In the ampulla of the uterine tube.

  
• How long can an oocyte be fertilized after ovulation?

  Up to 24 hours.
• What is an ectopic pregnancy?

  Implantation occurring anywhere other than the uterine cavity.
• What are the sources, targets, and responses of key hormones in the reproductive cycle?

  • GnRH: Hypothalamus → Anterior Pituitary → Stimulates LH and FSH production.
  • LH: Anterior Pituitary → Ovaries → Follicle maturation and corpus luteum formation.
  • FSH: Anterior Pituitary → Ovaries → Follicle development.
  • Estrogen: Ovaries → Mammary glands, Uterus → Development and feedback regulation.
  • Progesterone: Corpus luteum → Mammary glands, Uterus → Endometrial preparation and feedback regulation.

  
• What is the role of inhibin in the reproductive cycle?

  It inhibits FSH production when enough follicles have developed.

  
• What happens to the endometrial layer during the secretory phase?

  It reaches its greatest thickness in preparation for implantation.
• How does the hormonal feedback mechanism regulate the reproductive cycle?

  Estrogen and progesterone exert negative feedback on FSH and LH after ovulation, while high estrogen levels can trigger a positive feedback before ovulation.