pelvic floor
DESCRIPTION
PELVIC FLOOR. PERINEAL BODY is essential for the integrity of the pelvic floor, particularly in females. Levator ani- 3 striated muscles: Puborectalis Pubococcygeous Iliococcygeous . Puborectalis is innermost and merges with the external anal sphincter. - PowerPoint PPT PresentationTRANSCRIPT
PELVIC FLOOR
PERINEAL BODY is essential for the integrity of the pelvic floor, particularly in females
Levator ani- 3 striated muscles:PuborectalisPubococcygeous Iliococcygeous
Puborectalis is innermost and merges with the external anal sphincter.
Causes 120 deg angulation of anorectum due to the pull against the pubic bones.
Shuts the lumen by apposing the post and the side walls of rectum
Puborectalis – from myotome S1-S4
Pubococcygeous and iliococcygeous help to close the urogenital diaphragm
EXTERNAL ANAL SPHINCTER:Superficial external sphincterDeep external sphincter – continuous
with the puborectalis
The external anal sphincter and puborectalis muscles are innervated by the pudendal nerve.
INTERNAL ANAL SPHINCTERCircular layer of rectum becomes
internal anal sphincter
Colon innervation:Intrinsic1. Auerbach plexus- segmentation and peristalsis2. Plexus of Meissner- secretions and sensationExtrinsic3. Parasympathetic increases and relaxes sphincters4. Sympathetic decreases motility and contracts
sphincters
The muscular wall of the cecum and colon is innervated by:
Vagus nerve- cranial nerve X in PNSSuperior mesenteric plexus – SNS cord segment
T9-L2
The rectum and anal canal innervation:Pelvic splanchnic nerves- parasympathetic S2-4Hypogastric nerve- sympathetic T11-L2
Anal sphincters innervation:Internal anal sphincter- pelvic splanchnic
nerves and hypogastric nervesExternal anal sphincter – pudendal nerve
Neural organization of anorectal sphincters:Somatic from S2,3,4 (pudendal nerve)to the external anal sphincterSympathetic from L2,3,4 (superior hypogastric
plexus/pelvic plexus) through hypogastric nerve to the internal anal sphincter
Parasympathetic S2-4 (nervi erigentis or pelvic splanchnic nerves) to the internal anal sphincter
ADDITIONAL SLIDES FOR URINARY SYSTEM