(6.2) The Pelvic Region Flashcards
What bony structures form the Pelvic Griddle?
- Sacrum
- 2 x Hip Bones (Ilium + Ischium + Pubis)
What bony structures form the Pelvic Inlet?
- Promontory and Ala of Sacrum
- Linea Terminalis
What structures form the Pelvic Outlet?
- Tip of Coccyx
- Ischial Tuberosities
- Sacrotuberous Ligaments
- Pubic Arch/Subpubic Angle
At what angle should the Pelvic Inlet be at in an erect position?
60 degree to the horizontal
How are the following measured?
- Anatomic Conjugate
- Obstetric Conjugate
- Diagonal Conjugate
From Promontory of Sacrum to:
- Anatomic: Superior border of Pubic Symphysis
- Obstetric: Mid-point of Pubic Symphysis
- Diagonal: Inferior border of Pubic Symphysis
Contrast the following structures between male and female:
- General Pelvis
- Greater Pelvis
- Lesser Pelvis
- Pelvic Inlet
- Pelvic Outlet
- Pubic Arch/Subpubic Angle
- Obturator Foramen
- Acetabulum
- Greater Sciatic Notch
- General Pelvis - M: thick & heavy; F: thin & light
- Greater Pelvis - M: deep; F: shallow
- Lesser Pelvis - M: deep & tapering; F: shallow & cylinderincal
- Pelvic Inlet - M: narrow & heart shaped; F: wide & oval
- Pelvic Outlet - M: narrow; F: wide
- Pubic Arch/Subpubic Angle - M: Pubic Arch 80 degrees
- Obturator Foramen - M: round; F: oval
- Acetabulum - M: large; F: small
- Greater Sciatic Notch - M: ~70 degrees; F: ~90 degrees
Describe a ‘good pelvis’ for childbirth.
- Relative flat pelvic walls
- Wide pelvic inlet & outlet
- Stretchy Sacrotuberous Ligament (achieved by Progesterone)
- Subpubic angle > 90 degrees
- Well-curved Sacrum (fit in foetal head)
- Well-rounded Greater Sciatic Notch
What structures form the Pelvic Floor?
- Pelvic Diaphragm (Levator Ani + Coccygeus)
- Urogenital Perineum
- Anal Perineum
What structures form the Pelvic Diaphragm?
- Levator Ani (Puborectalis + Pubococcygeus + Iliococcygeus)
- (Ischio)coccygeus
What are the functions of the Pelvic Diaphragm?
- Supports Pelvic viscera
- Resist high abdominal pressure (coughing, defecation, lifting, etc)
- Exerts sphincter actions on rectum & vagina
- Separates Pelvic cavity from Perineum
What are Greater pelvis and Lesser pelvis?
- Greater pelvis = area above Pelvic Inlet, bounded posterosuperiorlly by S1 vertebra; consist of abdominal viscera (Ileum & Sigmoid Colon etc)
- Lesser pelvis = area between Pelvic Inlet & Outlet; consists of Pelvic Cavity & Floor
What structures bound the Pelvic Cavity superiorly and inferiorly?
- Superiorly: Pelvic Inlet
- Inferiorly: inferior margin of Pelvic Diaphragm
What structures form the Urogenital Perineum? What structures are consist within it?
- Superficial Fascia & External Urethral Sphincter & Inferior Fascia (Perineal Membrane)
- Urethra & Vagina & Bulbourethral Glands
Where is the Superficial Perineal Pouch? How may an infection spread in this area?
- Below Perineal Membrane (Inferior Fascia of Urogenital Perineum)
- Infection from Anus spread posteriorly
What structures form the Anal Perineum? What structures are consist within it?
- Levator Ani
- Anus
- Ischiorectal Fossae (Pudenal Nerve passes along it)
