LL Pelvic Walls and Cavity

• What are the main functions of the pelvis?

  • Transmits body weight to femurs
  • Supports and protects pelvic viscera
  • Provides muscle attachment for trunk and LE
• What is the region of the trunk below the abdomen called?

  Pelvis
• How many bones compose the pelvis?

  4 bones
• What are the bones that make up the pelvis?

  2 hip bones, sacrum, coccyx
• What are the three articulations of the pelvis?

  1. Pubic symphysis
  2. Sacroiliac
  3. Sacrococcygeal
• What is the correct orientation of the pelvis?

  • Symphysis pubis and ASIS in same vertical plane
  • Pelvic surface of pubic symphysis faces upward and backward
  • Anterior surface of sacrum faces forward and downward
• What does the pelvic brim divide the pelvis into?

  1. False pelvis
  2. True pelvis
• What forms the pelvic brim or inlet?

  1. Posterior: Sacral promontory
  2. Lateral: Iliopectineal lines
  3. Anterior: Symphysis pubis
• What forms the pelvic outlet?

  1. Posterior: Coccyx
  2. Lateral: Ischial tuberosities
  3. Anterior: Pubic arch
• What are the characteristics of the false pelvis?

  • Part of the abdominal cavity
  • Boundaries: lumbar vertebrae, iliac fossa, lower abdominal wall
• What are the characteristics of the true pelvis?

  • Has an inlet, outlet, and cavity
  • Boundaries: sacral promontory, iliopectineal lines, symphysis pubis
• What are the pelvic walls and their characteristics?

  1. Anterior = shallowest
  2. Posterior = extensive
  3. Lateral
  4. Inferior = pelvic floor
• What structures make up the anterior wall of the pelvis?

  1. Bodies of pubic bones
  2. Pubic rami
  3. Symphysis pubis
• What structures make up the posterior wall of the pelvis?

  1. Sacrum
  2. Coccyx
  3. Piriformis muscle
  4. Parietal pelvic fascia
• What structures make up the lateral wall of the pelvis?

  1. Hip bone below pelvic inlet
  2. Obturator membrane
  3. Sacrotuberous and sacrospinous ligaments
  4. Obturator internus
• What is the pelvic floor and its function?

  • Formed by pelvic diaphragm
  • Divides pelvis into main pelvic cavity above and perineum below
  • Incomplete anteriorly for urethra and vagina passage
• What muscles form the pelvic diaphragm?

  1. Levatores ani (including puborectalis, pubococcygeus, iliococcygeus)
  2. Coccygeus
• What structures make up the inferior wall of the pelvis?

  1. Pelvic diaphragm (levator ani and coccygeus)
• How does the male pelvis differ from the female pelvis?

  • Male: shallow false pelvis, heart-shaped inlet
  • Female: deep false pelvis, transversely oval inlet
• What are the differences in pelvic cavity dimensions between males and females?

  • Male: narrower cavity, longer distance between inlet and outlet
  • Female: wider cavity, shorter distance between inlet and outlet
• What are the differences in pelvic outlet size between males and females?

  • Male: smaller outlet
  • Female: larger outlet
• How do the sacrum shapes differ between male and female pelvises?

  • Male: longer, narrower, more curved
  • Female: shorter, wider, flatter
• What is the difference in subpubic angle between male and female pelvises?

  • Male: angular and narrower
  • Female: rounded and wider
• What are the three articulations of the pelvic joints?

  1. Pubic symphysis
  2. Sacroiliac
  3. Sacrococcygeal
• What is the pelvic cavity and its subdivisions?

  • Cavity of the true pelvis
  • Area between pelvic inlet and outlet
  • Subdivided into main pelvic cavity above and perineum below
• What are the contents of the pelvic cavity?

  1. Sigmoid colon
  2. Rectum
  3. Ureter
  4. Urinary bladder
  5. Male genital organs
  6. Female genital organs