Vesica sphincter muscle

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Vesica sphincter muscle
origin
surrounds the outlet of the bladder (ostium urethrae internum)
approach
surrounds the outlet of the bladder (ostium urethrae internum)
function
Maintaining continence
Innervation
Pudendal nerve
Spinal segments
S2-S4

As sphincter vesicae ( "bladder sphincter") or sphincter vesicae internus ( "internal sphincter of the bladder") is a sphincter ( sphincter ) at the output of the bladder ( urethral orifice internum hereinafter).

The muscle appears as a continuation of the detrusor vesicae muscle (expeller of the urinary bladder), but is a completely independent unit in terms of anatomy, function and innervation .

The sphincter vesicae muscle plays a crucial role in emptying the bladder ( micturition ). Signals from the parasympathetic nervous system (via the pudendal nerve ) relax the muscle, so that the contents of the bladder are no longer held back. Conversely, signals from the sympathetic nervous system cause the sphincter to contract, which prevents the bladder from emptying.

literature

  • Maurice Stephan Michel, Joachim W. Thüroff, Günther Janetschek, Manfred Wirth (eds.): Die Urologie , Springer-Verlag, Berlin 2016, ISBN 9783642399404 , especially p. 1395f, preview Google Books .

Individual evidence

  1. ↑ Schünke M, Schulte E, Schumacher U: Poster Urology Scan 4-2016. In: Urology Scan. 03, 2016, p. 254, doi : 10.1055 / s-0042-114139 , based on: Schünke M, Schulte E, Schumacher U. Prometheus. LernAtlas der Anatomie. Internal organs. Illustrations by M. Voll and K. Wesker . 4th, revised and expanded edition, Thieme, Stuttgart 2015, ISBN 978-3131395344 .
  2. ^ W. Dorschner, JU Stolzenburg, J. Neuhaus: Structure and function of the bladder neck. In: Advances in anatomy, embryology, and cell biology. Volume 159, 2001, III – XII, pp. 1–109, PMID 11417142 (Review), p. 29, preview Amazon , preview Google Books
  3. ↑ J. Jung, HK Ahn, Y. Huh: Clinical and functional anatomy of the urethral sphincter. In: International neurourology journal. Volume 16, number 3, September 2012, pp. 102-106, doi : 10.5213 / inj.2012.16.3.102 , PMID 23094214 , PMC 3469827 (free full text) (review).
  4. ↑ P. Sam, CA LaGrange: Anatomy, Abdomen and Pelvis, Sphincter Urethrae . In: StatPearls [Internet] . February 2019. PMID 29494045 . (Review).