Fig. 16.1 Simplified schema of the GnRH-LH-testosterone (hypothalamo-pituitary-Leydig cell) axis with feedback (−, inhibitory) and feedforward (+, stimulatory) interactions mediated via specific interface (dose-response) functions Fig. 16.2 Primary loci of postulated regulatory…
Fig. 10.1 Undescended testes along the pathway of normal testicular descent into the scrotum, and ectopic locations. Illustration by Dr. James Grubola, Professor of Fine Arts, University of Louisville Congenital cryptorchidism…
Fig. 13.1 Illustrated are the factors that influence circulating testosterone levels in normal men at rest and in response to a physical exercise bout. This figure is based upon the information…
Fig. 5.1 Schematic presentation of the activity of the hypothalamic–pituitary–gonadal axis across the life cycle. During the neonatal window, pulsatile GnRH stimulates LH and FSH secretion which induce adult levels of…
Fig. 2.1 Fetal testis. a Fetal mouse: low magnification of a semi-thin section showing seminiferous tubules (ST) and interstitial tissue (I). b Fetal mouse: higher magnification of (a) showing gonocytes (G)…
Fig. 1.1 Model depicting the role of ARC KNDy neurons in the generation of pulsatile GnRH release. KNDy neurons in the ARC nucleus form an interconnected population with their axons and/or…
Fig. 7.1 Adrenal steroid synthesis. StAR steroidogenic autoregulatory protein; SCC (cholesterol) side-chain cleavage enzyme; 3β-HSD 3β-hydroxysteroid dehydrogenase; 17β-HSD 17β-hydroxysteroid dehydrogenase Prevalence Most enzyme deficiencies that cause CAH are extremely rare, except…
Causes of chronic liver disease Prevalence in United States Associated type of hypogonadism Nonalcoholic fatty liver disease (NAFLD) 11% Unclear, but likely more secondary Alcoholic liver disease (ALD) 2% Both…
Fig. 17.1 Relationship between age and hormones. This figure shows mean hormone values at 5-year age bands with 95% confidence interval (shaded area) in 3220 European men. Mean hormone values with…
Ref. n BMI (kg/m2) Testosterone ng/dL (nmol/L) SHBG nmo/L MetS HOMA-IR Pre Post Pre Post Pre Post Pre Post Pre Post [148] 22 46.2 ± 0.9 −16.6% 340 ± 21 636 ± 186 +21.6 [149] 33 50.3 ± 6.1 31.5 ± 4.7 248 ± 91…
