Related Experiment Videos
Anal sphincter complex: reinterpreted morphology and its clinical relevance
Helga Fritsch1, Erich Brenner, Andreas Lienemann
1Department of Anatomy, University of Innsbruck, Innsbruck, Austria.
Diseases of the Colon and Rectum
|February 20, 2002
Summary
This study clarifies the anatomy of the anal sphincter complex, revealing it
Area of Science:
- Anatomy
- Histology
- Pelvic Floor Anatomy
Background:
- Clinical studies highlight a need for better morphologic understanding of the anal sphincter complex.
- Existing concepts lack reliability for clinical application.
Purpose of the Study:
- To define the detailed anatomy and histology of the human anal sphincter complex.
- Utilize undisturbed anatomic preparations for accurate visualization.
Main Methods:
- Examination of human pelves (fetal, newborn, adult) using axial, sagittal, and coronal sections.
- Histologic analysis of sphincter tissues.
Main Results:
- The anal canal is encircled by internal and external sphincters and a longitudinal muscle layer.
- The classical tripartite subdivision of the external sphincter was not supported.
- The external sphincter's circularity varies in certain planes, with sexual dimorphism evident early in development.
- Lamellated corpuscles innervated by the pudendal nerve were observed within the muscle layers.
Conclusions:
- Anatomical findings align with advanced imaging (MRI, endosonography) and physiological data.
- This detailed understanding is crucial for managing sphincter defects from childbirth and for anorectal surgeries in all age groups.