CHAPTER 10

• What are the muscles of the pelvic floor?

  Levator ani and coccygeus

  
• What is the pelvic diaphragm?

  Muscles stretching from pubis to coccyx

  
• What are the components of the levator ani?

  Pubococcygeus and iliococcygeus

  
• What is the origin of the pubococcygeus?

  Pubis
• Where does the pubococcygeus insert?

  Coccyx, urethra, anal canal

  
• What is the action of the pubococcygeus?

  Supports pelvic viscera and resists pressure

  
• What nerves innervate the pubococcygeus?

  Sacral spinal nerves S2-S4

  
• What is the origin of the iliococcygeus?

  Ischial spine
• Where does the iliococcygeus insert?

  Coccyx

  
• What is the action of the iliococcygeus?

  Supports pelvic viscera and resists pressure

  
• What nerves innervate the iliococcygeus?

  Sacral spinal nerves S2-S4

  
• What is the origin of the coccygeus?

  Ischial spine
• Where does the coccygeus insert?

  Lower sacrum and upper coccyx
• What is the action of the coccygeus?

  Supports pelvic viscera and pulls coccyx

  
• What nerves innervate the coccygeus?

  Sacral spinal nerves S2-S4
• How does the levator ani muscle affect childbirth?

  Supports fetus and may be injured

  
• What is a consequence of levator ani injury?

  Urinary stress incontinence
• What exercise is recommended for pelvic floor strengthening?

  Kegel exercises
• What is the perineum?

  Region inferior to pelvic diaphragm

  
• Describe the shape and extent of the perineum.

  Diamond-shaped from pubis to coccyx

  
• Why is the perineum clinically important?

  Relevant for pregnancy and genital disorders
• What does the urogenital triangle contain?

  External genitals

  
• What does the posterior anal triangle contain?

  Anal canal
• How are perineum muscles arranged?

  In two layers: superficial and deep

  
• Name a superficial perineal muscle.

  Bulbospongiosus

  
• What is the origin of the superficial transverse perineal muscle?

  Ischial tuberosity

  
• What is the action of the superficial transverse perineal muscle?

  Stabilizes perineal body

  
• What innervates the superficial transverse perineal muscle?

  Perineal branch of sacral plexus

  
• What is the origin of the bulbospongiosus?

  Perineal body of perineum
• What are the actions of the bulbospongiosus?

  Expels urine and assists erection
• What innervates the bulbospongiosus?

  Perineal branch of sacral plexus
• What is the origin of the ischiocavernosus?

  Ischial tuberosity and rami
• What is the action of the ischiocavernosus?

  Maintains erection of penis and clitoris
• What innervates the ischiocavernosus?

  Perineal branch of sacral plexus

  
• What is the origin of the deep transverse perineal muscle?

  Ischial rami

  
• What is the action of the deep transverse perineal muscle?

  Expels last drops of urine and semen

  
• What innervates the deep transverse perineal muscle?

  Perineal branch of sacral plexus

  
• What is the origin of the external urethral sphincter?

  Ischial and pubic rami

  
• What is the action of the external urethral sphincter?

  Expels last drops of urine and semen

  
• What innervates the external urethral sphincter?

  Sacral spinal nerve S4