RT Book, Section
A1 Bhasin, Shalender
A1 Jameson, J. Larry
A2 Jameson, J. Larry
SR Print(0)
ID 1141274911
T1 Disorders of the Testes and Male Reproductive System
T2 Harrison's Endocrinology, 4e
YR 2017
FD 2017
PB McGraw-Hill Education
PP New York, NY
SN 9781259835728
LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1141274911
RD 2024/04/16
AB The  male  reproductive  system  regulates  sex  differentiation,  virilization,  and  the  hormonal  changes  that  accompany  puberty,  ultimately  leading  to  spermatogenesis  and  fertility.  Under  the  control  of  the  pituitary  hormones—luteinizing  hormone  (LH)  and  follicle-stimulating  hormone  (FSH)—the  Leydig  cells  of  the  testes  produce  testosterone  and  germ  cells  are  nurtured  by  Sertoli  cells  to  divide,  differentiate,  and  mature  into  sperm.  During  embryonic  development,  testosterone  and  dihydrotestosterone  (DHT)  induce  the  wolffian  duct  and  virilization  of  the  external  genitalia.  During  puberty,  testosterone  promotes  somatic  growth  and  the  development  of  secondary  sex  characteristics.  In  the  adult,  testosterone  is  necessary  for  spermatogenesis,  stimulation  of  libido  and  normal  sexual  function,  and  maintenance  of  muscle  and  bone  mass.  This  chapter  focuses  on  the  physiology  of  the  testes  and  disorders  associated  with  decreased  androgen  production,  which  may  be  caused  by  gonadotropin  deficiency  or  by  primary  testis  dysfunction.  A  variety  of  testosterone  formulations  now  allow  more  physiologic  androgen  replacement.  Infertility  occurs  in  ~5%  of  men  and  is  increasingly  amenable  to  treatment  by  hormone  replacement  or  by  using  sperm  transfer  techniques.  For  further  discussion  of  sexual  dysfunction,  disorders  of  the  prostate,  and  testicular  cancer,  see  Chaps.  19,  and  12,  respectively.