[Afferent innervation of musculus sphincter ani externus of men]

Investigations of the existence and distribution of muscle spindles and tendon organs in the human voluntary anal sphincter muscle in 53 cases of autopsy material from both female and male persons (age: 27th week of gestation to 81 years) brought forward the following results: Similar to animals, muscle spindles are formed in the last trimenon of gestation. They are more numerous as has been expected hitherto and there are different types with a different content of intrafusal fibers. Lamellar corpuscular organs are situated around the ending of the muscle fibers in the anal skin. In our opinion they are to substitute muscle tendon organs which could not be detected.