The neuroendocrine control of reproduction is reviewed in Part 1, Chapter 1 of this volume. Reproductive dysfunction of central etiology can result from any process that disturbs the tightly regulated hypothalamic-pituitary system. The reproductive axis itself relies on pulsatile release…
Acknowledgments The authors gratefully acknowledge the contribution of Patrice Sutton of PRHE and Jessica Trowbridge, MPH, UC Berkeley, who contributed to the previous (8th Edition) of this chapter. Funding to support this work was provided to UCSF’s Program on Reproductive…
Introduction In males, pulsatile gonadotropin-releasing hormone (GnRH) and gonadotropin secretion are secreted at a mean interval of every 2 hours, a frequency sufficient to maintain testosterone levels, virilization, and spermatogenesis. In females, a more complex series of gonadal tasks must…
Introduction Puberty in humans is defined as the period of first becoming capable of reproducing and is distinguished by maturation of the genital organs, development of secondary sex characteristics, acceleration in linear growth velocity, changes in affect, and the occurrence…
Introduction Our individual sex has a major role in determining the physical attributes of our bodies, the structure of our brains, our behavioral tendencies, and our self-concept. Understanding how biological sex differences arise has both informed and been informed by…
Introduction The relationship between a living organism and its environment is based on a tightly regulated balance between symbiosis and competition. Survival is dependent upon appropriate resource acquisition, permissive physicochemical environments, and competition for limiting resources and ecological niches exerted…
As men age, reproductive function declines in several ways. Although the change is gradual, unlike the relatively abrupt decline that occurs in women at the time of menopause, it is progressive and probably has some adverse consequences. The decline is…
Epidemiology The age of menopause has been constant over several centuries and is influenced by genetic, ethnic, and environmental variables. The prediction of the age of menopause based on antimüllerian hormone (AMH) trajectories is possible but impractical. Menopause is defined…
Physiology of the Male Gonadal Axis Gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (Te), and estradiol (E 2 ) are the major ligands (hormones) of the male gonadal axis. Pulsatile secretion of these hormones allows feedforward (stimulatory)…
Exclusive breastfeeding can produce amenorrhea for up to 6 months postpartum by inhibiting GnRH secretion. Breastfeeding is associated with a reduced risk of developing endometriosis, type 2 diabetes mellitus, hypertension, and breast and ovarian cancer. Introduction Structural and Histological Features…