Pelvis Flashcards
Anatomy: Pelvis res & Bones
perineum
located between the thighs nd represents most inferior part of pelvic outlet.
Contains structures that support the urogenital and gastrointestinal systems,
anatomical boundaries of perineum
Anterior; pubic symphysis posterior: tip of coccyx laterally: inferior pubic rami and inferior ischial rami and sacrotuberous ligament Roof: pelvic floor Base: skin and fascia
boundaries of anal triangle
Coccyx, sacrotuberous ligament and line between ischial tuberosities
Contents of nail triangle
Anal aperture.
External anal sphincter muscle
Ischioanal fossa (fat & connective tissue. Extend from skin of anal region to pelvic diaphragm)
Nerve supply of perineum
pudendal nerve: supplies whole perineum with somatic fibres
Urogenital triangle boundaries
pubic symphysis
ischiopubic rami
line between ischial tuberosities
Associated with structures of urogenital system: external genitalia and urethra
Layers of urogenital triangle
deep perineal pouch perineal membrane superficial peroneal pouch perineal fascia skin
Deep perineal pouch
potential space between deep fascia of pelvic floor and perineal membrane
Contains urethra, external urethral sphincter and vagina
Perineal membrane
layer of tough fascia, perforated by urethra and vagina
provides attachment for muscles of external genitalia
superficial perineal pouch
potential space between perineal membrane and superficial perineal fascia
Contains erectile tissue that forms clitoris.
Muscles: ischiocavernosis, bulbospongiosus and superficial transverse perineal muscles
Location of Bartholin’s glands
Perineal fascia
continuity of abdominal fascia that has 2 components: superficial and deep fascia
Deep fascia; coverei superficial perineal muscles and protruding structures
Superficial fascia has superficial and deep layer
Skin of urogenital triangle
urethral and vaginal orifices open out onto skin
perineal body
irregular fibromuscular masss
located at junction of urogenital and anal triangles.
contains skeletal muscle, smooth muscle, and collagenous and elastic fibres
Perineal body- attachments
Acts as a point of attachment for muscle fibres from pelvic floor and perineum itself
- levator ani
- bulbospongiosus muscle
- superficial and deep transverse perineal muscles
- external anal sphincter muscles
- external urethral sphincter muscle fibres
perineal body function
Point of attachment
Tear resistant body between vagina and external anal sphincter
Supports posterior part of vaginal wall against prolapse
perineum neuromuscular supply
Pudendal nerve (S2-S4) Internal pudendal nerve
sciatic foramen
greater and lesser sciatic foramen,
2 openings in posterior aspect of pelvis
Separated by Sacrospinous ligament
greater sciatic foramen
provides passageway for structures to pass from pelvis into gluteal region
greater sciatic foramen borders
superior: anterior sacroiliac ligament
posteromedial: sacrotuberous ligament
Anterolateral: greater sciatic notch of ilium
Inferior: Sacrospinous ligament and ischial spine
contents of greater sciatic foramen
divided into 2 by piriformis muscle
Suprapiriform
- superior gluteal artery and nerve
- superior gluteal nerve
Infrapiriform foramen
- sciatic nerve
- pudendal nerve
- inferior gluteal artery and vein
- inferior gluteal nerve
- posterior femoral cutaneous nerve
- nerve to obturator interns
- nerve to quadratus femoris
Lesser sciatic foramen
provide a communication between perineum of pelvis and gluteal region.
Lies inferiorly to pelvic floor.
lesser sciatic foramen borders
superior; Sacrospinous ligament and ischial spine
Anterior: ischial spin, lesser sciatic notch, and ischial tuberosity
Posterior: sacrotuberous ligament