The Pelvic Floor

The Pelvic Floor Bearbeitet von Beate Carrière, Cynthia Markel Feldt 1. Auflage 2006. Buch. 496 S. ISBN 978 3 13 139211 4 Format (B x L): 17 x 24 cm Weitere Fachgebiete > Medizin > Klinische und Innere Medizin > Gynäkologie, Geburtshilfe, Materno-Fetal, Hebammen Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. 16 1Basics Micturition center Lumbar spinal cord T10–L2 Inferior hypogastric Stretch plexus receptor Pelvic nerve Bladder Sacral Pelvic floor spinal cord External Pudendal nerve S2–S4 urethral Stimulating sphincter Inhibitory Fig. 1.17 The nerves of the urogenital complex. traction of the smooth muscle of the detrusor. The Anorectal Complex Micturition is initiated by opening of the bladder neck, and is continued into dilation of the urethra, The anal hiatus lies in the posterior part of the allowing urine to flow unimpeded. In the male, fibrous arch of the levator. The anal canal, sur- the bladder neck is also subject to adrenergic con- rounded by the external anal sphincter, passes trol, closing the bladder during ejaculation. through it to its external opening. As in the uro- The lower urinary tract is therefore regulated genital hiatus, striated and smooth muscles by a relatively simple reflex arc, which, however, meet in this hiatus, where they are important is under the influence of the central nervous factors in maintaining fecal continence. When system (pontine micturition center, sacral spinal either somatic or autonomic minor motor prob- cord) [Merkle 1997]. lems occur, the plasticity of the CNS should From a physiotherapeutic point of view, it accommodate to maintain function. That adapta- should be noted that the musculature of the pel- tion or plasticity will occur more easily following vic floor takes part in the physiologic control of motor learning principles. (See the section on urinary outflow. The relaxation of the muscles motor learning and motor control, pp. 21–35, of the pelvic floor needed for micturition is facili- for additional information.) tated by certain body postures, such as sitting The striated musculature in this area consists [Wennergren and Oberg 1995]. On the other of parts of the external anal sphincter, which hand, in other postures muscular activity in- receives its somatic innervation through the creases and so supports continence. These two pudendal nerve (S2–S4) (Fig. 1.18). Superiorly, examples are linked to interactions of the pelvic the sling of the puborectalis is continuous with floor muscles with central motor programming the striated external anal sphincter. Its somatic and synergic patterns [Shumway-Cook and innervation is mixed, with afferents from both Woollacott 2001]. the pudendal nerve and the sacral plexus com- Carri re, The Pelvic Floor (ISBN 3131392118) c 2006 Georg Thieme Verlag 1.1 Anatomy and Physiology of the Pelvic Floor 17 Fig. 1.18 The nerves of the anorectal complex. Onuf’s nucleus Inferior mesenteric plexus Inferior hypogastric plexus Pudendal plexus Superior fascia of pelvic diaphragm Nerves to levator muscle Inferior rectal nerves Longitudinal part of levator ani Pudendal nerve Puborectalis muscle Internal anal sphincter External anal sphincter municating sensory information to the CNS system.Whatisacceptedisthatthisregionre- [Roberts et al. 1988]. ceives sympathetic efferents from the inferior The motoneurons for the striated sphincters thoracic cord and the lumbar cord (T6–L2), as originate lateral to the anterior horn cells of well as parasympathetic efferents from S2–S4 the respective segments of the spinal cord (pelvic splanchnic nerves). Yamamoto et al. (Fig. 1.18). This collection of cells is known as [1978] determined the presence of nerve cell col- Onuf’s nucleus [Schræder 1981]. lections in Onuf’s nucleus supplying the smooth The smooth muscles of the internal anal muscle of the internal anal sphincter, while de- sphincter and the outer longitudinal layer are in- monstrating that the nuclei for the striated and nervated by the autonomic nervous system. smooth parts of the sphincter are difficult to se- However, the mechanisms are less well known parate. The autonomic nerves reach the rectum than those of the smooth muscle of the urinary and anal canal by way of the inferior hypogastric Carri re, The Pelvic Floor (ISBN 3131392118) c 2006 Georg Thieme Verlag 18 1Basics plexus. Apart from this extramural autonomic Following injury that causes loss of function in nerve supply, both of these organs possess an in- sensory, motor, or both neurons, the patient tramural nervous network [Wedel et al. 1999] si- may experience an imbalance in function or re- milar to that of the colon segments above them. sponse in the learned motor programs. Strength- The structure and function of this network have ening weak muscles in isolation from the motor not yet been adequately defined. programs will not guarantee that the established Tonic contraction of both sphincters closes the power will automatically transform into ade- anal canal, with the internal anal sphincter con- quate motor programs. Linking motor learning tributing about 80 % and the external anal sphinc- with motor control and the interactions of sen- ter about 20 % [Stelzner 1998, Schfer and Enck sory input and motor pattern responses will 1997]. The closure of the anal canal is also sup- lead to the most efficacious interventions. For ex- ported by the puborectalis muscle, which contri- ample, a child initially has no control over emp- butes to a sharp angling of the anorectal angle, tying the rectum. The elimination is automatic/ which in turn prevents passage of the stool reflexive and a response to tension within the from the rectum into the anal canal. Schumann rectum. The child learns through repetition and [1986] was able to show that the physiologic practice to sense afferent stimuli coming from strength of the puborectalis muscle is distinctly the increased tension within the rectum. Simul- greater in the male than in the female, and this taneously, the child learns to inhibit reflexive re- is in agreement with morphologic investigations laxation of the striated sphincter and thus learns of the structure of the sphincter apparatus bowel control. The child learns and thus practices [Fritsch et al. 2002]. According to this work, the releasing fecal matter in a seated position or anal canal in the female is closed voluntarily by squatting, depending on the local culture. In perineal contraction occurring below the level both functional positions gravity and the abdom- of the urethral and vaginal openings. The exter- inal muscles are used to assist in elimination. nal closure of the intestinal tube by muscular Thus, sitting and squatting become the environ- contraction is further enhanced internally by vas- mentally specific functional positions that a pa- cular engorgement of the corpus cavernosum tient must practice prior to being functionally in- recti (arteriovenous plexus). dependent in both retention and elimination. An- Like micturition, defecation is regulated by a other spatial position might initially be incorpo- nervous reflex arc, the details of which, however, rated, such as supine, with the legs over a gym- have not yet been completely clarified. Initially, nastic ball. This position takes away the stretch the wall of the rectal ampulla is distended by to the pelvic muscles and postural stability of an increase in fecal mass. The anatomic location the pelvic floor and back muscles needed for sit- of the corresponding stretch receptors has not ting. The patient can practice pelvic tilts while been defined. It has been established, however, contracting and relaxing the anal region. The that the response to an increase in tension in therapist should be looking for anal contraction the wall of the rectal ampulla is contraction of during both anterior and posterior tilts, as well the sphincters. When the rectum empties, the as relaxation during those movements. As the pa- sphincters are relaxed, although the striated tient is moving the ball toward and away from sphincter can “intervene” at any time and post- the hips, during tilts and squeeze/release move- pone defecation for a time by contracting volun- ments he or she will be practicing a variety of tarily. motor programs. The therapist can then move Normal defecation is aided by contraction of the patient to the sitting position and continue the anterior abdominal muscles, especially the with the same exercises. This upright position re- transversus abdominis. This increases intra- quires integration of postural programs of the abdominal pressure, and this—in contrast to the back and their interaction with abdominal mus- brief rise in intra-abdominal pressure accompa- cles for stabilization of the trunk in vertical. Pro- nying coughing and sneezing—is accompanied gressing first to a hard base, which eliminates the by relaxation of the pelvic floor, including the organ stretch to the pelvic floor, should be easier puborectalis muscle. Practicing this motor con- than a toilet surface that increases the pull of trol as a small child leads to the capacity of the gravity on the organs and the need for sphincter CNS for motor learning and thus

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