Hormonal control of reproduction

• Pituitary gland


  releases FSH, LH or ICSH in response to releaser hormone
• Hypothalamus


  releases Releaser hormone, which acts on the pituitary gland
• Triggers of puberty onset


  Release of FSH, LH or ICSH from the pituitary gland
• Males: Role of FSH


  promotes sperm production
• Males: Role of ICSH


  Stimulates the production of testosterone
• Males: Role of testosterone


  Stimulates sperm production and activates the prostate gland and seminal vesicles.
• Control of testosterone levels


  Negative feedback control by FSH and ICSH
• Duration of the average menstrual cycle

  28 days
• Day one of the cycle


  First day of menstruation
• Females: Role of FSH


  Stimulates the development of a follicle and production of oestrogen by the follicle
• Females: Follicular phase


  Development of a follicle in the first half of the menstrual cycle
• Females: Role of oestrogen


  proliferation of the endometrium preparing it for implantation. Affects consistency of cervical mucus
• Consequence of peak levels of oestrogen


  Surge in LH secretion
• Consequence of LH secretion peaks


  Triggers ovulation
• Luteal phase


  Follicle develops into a corpus luteum; progesterone secreted
• Role of progesterone


  promotes further development and vascularisation of the endometrium, preparing it for implantation if fertilisation occurs
• Control of follicular development is achieved by...


  negative feedback of the ovarian hormones on the pituitary gland and the secretion of FSH and LH.
• Consequence of lack of LH


  degeneration of the corpus luteum with a subsequent drop in progesterone levels leading to menstruation
• Hormone secreted by the corpus luteum

  progesterone
• If fertilisation occurs, the corpus luteum...


  does not degenerate and continues to produce progesterone