Table 2 Urethral striated muscle sex differences summary
From: Sex differences in lower urinary tract biology and physiology
| Species | Sex | Histologic studies | Functional studies | References |
|---|---|---|---|---|
| Rat | Female |
Striated muscle is thin and circular, prominently occupying the middle urethra. Type II fibers are predominant. |
Urine flow disrupted by partial/full closure of urethra Lower max flow rate and shorter micturition time |
Praud et al. [51] Lim et al. [52] Buffini et al. [56] Biérinx et al. [53] Streng et al. [59] |
| Male |
Striated muscle forms a thick layer. 100% type II fibers in the upper urethra. Luminal muscle contains a mix of type I and II fibers. | |||
| Human | Female | Striated muscle extends the length of the urethra and is composed of predominantly type I slow twitch fibers (87% vs. 13%). |
Benoit et al. [60] Ho et al. [62] | |
| Male | Striated muscle extends from the membranous urethra over the prostate and has a mixture of both slow and fast twitch fibers (65% vs. 35%). |