title: The male rectourethralis and deep transverse perineal muscles and their relationship to adjacent structures examined with successive slices of celloidin-embedded pelvic viscera.
abstract: BACKGROUND
  The precise relationship of the structures dorsal to the membranous urethra, including the rectourethralis muscle, the rhabdosphincter, the deep transverse perineal muscle (DTPM), the perineal body, and Denonvillier's fascia, remains controversial.
  
  
  OBJECTIVE
  Our aim was to reexamine the detailed anatomy of the rectourethralis muscle and the deep transverse perineal muscle and their relationship with adjacent structures.
  
  
  METHODS
  The pelvic viscera, including bladder, prostate, and rectum, were obtained from 20 formalin-fixed adult male cadavers.
  
  
  METHODS
  The pelvic viscera were embedded in celloidin and then cut into successive slices with an immersing-alcohol microtome. All slices were explored with anatomic microscopy.
  
  
  CONCLUSIONS
  The longitudinal muscle of the anterior rectal wall was divided into anterior and posterior bundles at the junction of the rectum and anal canal. The intermediate fibers of the anterior bundle ended at the perineal body. The lateral fibers of the anterior bundle terminated at the posterior connective tissue of the bulbus penis. The DTPM occupied the space between the rhabdosphincter, rectum, and the bilateral levator ani muscle. Denonvillier's fascia terminated at the junction of the prostate and rhabdosphincter. Numerous slender nerves coming from the neurovascular bundle perforated the DTPM.
  
  
  CONCLUSIONS
  The anterior bundle of the longitudinal muscle of the rectum inserts into the bulbus penis forming the rectourethralis muscle and ends at the perineal body forming the rectoperinealis muscle. The anterior bundle and DTPM together may contribute to the rectal angle of the anterior rectal wall, and they support the posterior border of the rhabdosphincter.
authors.affiliation: Department of Anatomy and Neurobiology, Tianjin Medical University, Tianjin, China.
authors.forename: Li-Dong
authors.initials: LD
authors.lastname: Zhai
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.forename: Yun-Sheng
authors.initials: YS
authors.lastname: Li
authors.forename: Qing-Tong
authors.initials: QT
authors.lastname: Ma
authors.forename: Ping
authors.initials: P
authors.lastname: Yin
mesh_terms: D002102:Cadaver; D003101:Collodion; D005404:Fixatives; D005557:Formaldehyde; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000294:innervation; D017773:Pelvic Floor / Q000033:anatomy & histology* / Q000294:innervation; D010502:Perineum / Q000033:anatomy & histology / Q000294:innervation; D010525:Peripheral Nerves / Q000033:anatomy & histology; D011467:Prostate / Q000033:anatomy & histology* / Q000294:innervation; D012007:Rectum / Q000033:anatomy & histology* / Q000294:innervation; D016610:Tissue Embedding; D001743:Urinary Bladder / Q000033:anatomy & histology* / Q000294:innervation
chemical_list: D005404:Fixatives; D005557:Formaldehyde; D003101:Collodion