Pelvis and Perinuem

  1. Functions of pelvis
    • 1. transmit upper body weight to the lower limbs providing a base for lower lib function
    • 2. Support and protect the pelvic viscera
    • 3. Form part of the birth canal during delivery
  2. Bony pelvis formed by
    • formed by 2 hip bones anteriorly and laterally
    • sacrum and coccyx posteriorly
  3. Parts of hip bone
    ilium, ischium and pubis
  4. 3 parts of hip bones fuse where?
    at the acetabulum at about 16 years to form a single bone at about 16 years
  5. Sacrum
    • Formed by fusion of 5 sacral vertebral segments
    • consists of base, apex, pelvic, dorsal, and lateral surfaces and a sacral canal
  6. Base of sacrum
    • upper surface of first sacral vertebra
    • articulates with 5th lumbar vertebral body at lumbosacral joint
  7. sacral promontory
    anterior projecting edge of the body
  8. lateral mass or ala
    wide upper part on each side of sacral promontory
  9. Pelvic surface
    four pairs of pelvic sacral foramina that transmit the ventral rami of S1-4
  10. Dorsal surface of sacrum
    • convex
    • contains: median sacral crest, medial sacral crest, four pairs of dorsal sacral foramina, lateral sacral crest
  11. median sacral crest
    3 or 4 spinous tubercles. in the middle of the sacrum
  12. Medial sacral crest
    four small articular tubercles lateal to median sacral crest.
  13. Sacral hiatus
    below the last median sacral spinous tubercles. bounded by the sacral cornua from the medial sacral crests on each side.
  14. dorsal sacral foramina
    transmit the dorsal rami of S1-4
  15. Lateral surface of sacrum
    • broad upper part with a mostly L-shaped auricular surface that articulates with the ilium at the sacroiliac joint.
    • Narrow lower part curves medially to the 5th sacral vertebral body at the inferior lateral sacral angle
  16. Apex of sacrum
    narrow, articulates with the base of the coccyx at the sacrococcygeal joint
  17. Sacral canal
    formed by the sacral vertebral foramina. Downward continuation of the vertebral canal. Four pairs of intervertebral foramina that are continuous with the pelvic and dorsal sacral foramina.
  18. Where does the subarachnoid space end
    level of the second sacral vertebra
  19. What does that sacral canal contain?
    Contains cauda equina, filum terminale and meninges
  20. What passes through the sacral hiatus
    filum terminale and S5 nerves
  21. Coccyx
    small triangular bone consisting of 4 fused vertebral segments. 2nds to 4th coccygeal vertebrae decrease in size and are fused bodies
  22. Base of coccyx
    upper surface of the 1st coccygeal vertebral body. Articulates with the apex of the sacrum.
  23. Coccygeal cornua
    project dorsolaterally from coccyx
  24. Transverse processes
    project superolaterally from coccyx
  25. Pelvic inlet
    plane bounded by the pelvic brim. Divided into the greater pelvis and the lesser pelvis
  26. Pelvic brim (linea terminalis)
    Extends along the promontory and ala of the sacrum, arcuate line of the ilium, pecten pubis, pubic crest and upper border of the symphysis pubis
  27. greater pelvis
    located above the pelvic inlet between the iliac bones and is part of the abdominal cavity
  28. lesser pelvis
    sitated below the pelvic inlet and forms the pelvic cavity or simply the pelvis
  29. Pelvic outlet
    diamond-shaped area extending from the symphysis pubis anteriorly tot eh coccyx posteriorly. Bound on each side by the ischiopubic ramus, ischiopubic ramus, ischial tuberosity and sacrotuberous ligament
  30. Maximum diameter of inlet in female
    transverse diameter is 13.5 cm
  31. maximum diameter of outlet in female
    anteroposterior or conjugate diameter of outlet ~11 cm
  32. Baby delivery
    fetal head turns 90° during delivery. Face to side as i passes through the inlet and faces posteriorly through the outlet
  33. Neutral position of the pelvis
    anterior superior iliac spines and upper end of the symphysis pubis are in the same vertical plane
  34. What does pelvic floor consist of
    • 1. (upper/deepest) Pelvic diaphragm.
    • 2. (middle) urogenital diaphragm - muscles of the deep perineal space
    • 3. (lower) muscles of the superficial perineal space.
  35. What muscles are in the pelvic diaphragm
    levator ani, coccygeus
  36. what is in the deep perineal space
    • deep transverse perinei mm,
    • sphnicter urethra mm,
    • bulbourethral glands (male
    • VAN's organs
  37. what is in the superficial perineal space?
    • superficial transverse perinei mm
    • bulbospongiousus mm
    • ischiocavernosus mm
    • greater vestibular glands (female)
    • erectile tissue, VAN's, organs
  38. Functions of the pelvic floor
    • 1. support the pelvic organs and contents
    • 2. Withstand any increases in pressure in the abdominopelvic cavity
    • 3. provide sphincter control of the perineal openings (urethra, vagina, and anus)
  39. Perineum
    • diamond shaped area between the thighs.
    • contrains the external genitalia and anal region.
    • Separated from the pelvic cavity by the pelvic diaphram.
    • = urogenital trianlge + anal triangle
  40. Urogenital triangle
    anterior to the ischial tuberosities, contains the external urogenital organs
  41. Anal triangle
    Posterior to ischial tuberosities, contains the end of the anal canal and anus
  42. What innervates the anal triangle
    anus and external anal sphincter both by the inferior rectal branch of pudendal nerve (S2-4)
  43. Ischioanal fossa
    • large wednged shaped space on each side of the ans filled with fat.
    • pudendal nerve, artery, and vein are found here
  44. External genitalia of the female
    Mons pubis, labia majora, labia minora, vesitbule, bulbs of vestibule, clitoris, greater vestibular glands
  45. What does labia minora form
    the prepuce and frenulum of the clitoris
  46. Vestibule has?
    contains opening of the urethra and vagina
  47. What are the bulbs of the vestibule
    erectile tissue lying on each side of the vaginal opening
  48. clitoris
    erectile tissue consisting of two crura and a body ending in the glans
  49. greater vestibular (bartholin's) glands
    secrete mucus for vaginal lubrication
  50. External genitalia of the male
    penis, scrotume
  51. Penis erectile tissue
    • paired dorsal corpora cavernosa
    • unpaired venral corpus spongiosum
  52. dorsal coporora cavernosa attachments
    attaches along the ischiopubic ramus by its crus
  53. ventral corpus spongiosum contains
    • the urethra and ending in the enlarged glas
    • bulb is attaches to the perineal membrane
  54. Scrotum
    fibromuscular sac of skin containing the testes and lower parts of the spermatic cords
  55. Dartos muscle
    layer of smooth muscles that wrinkle the skin of the scrotum
  56. Muscles of the superficial perineal space
    • lie between Colle's fascia (membranous layer of the superficial fascia) and the inferior fascia of the urogenital diaphragm (perineal membrane)
    • - Bulbospongiosus (bulbocavernosus) muscles
    • - ischiocavernosus muscles
  57. Bulbospongiosus muscles
    covering the corpus spongiosum in the male and bulbs in the vestibule in the female
  58. ischocavernosus muscles
    cover the crura of hte penis and clitoris
  59. Action of the bulbospongiosus and ischiocavernosus
    • Both - maintain erection by compressing veins
    • Male - bulbospongiousus helps empty the urethra after bladder has emptied
    • Female - sphincter of the vaginal opening
  60. innervation of muscles of the superficial perineal space
    pedendal nerve (S2-4) perineal branch
  61. Muscles of the deep perineal space
    • lie between the superior and inferior fascias of the urogential diaphragm. Muscles + their fascia = urogenital diaphragm.
    • sphrincter urethrae
  62. sphincter urethrae
    surrounds the membranous urethra and must be voluntarily relaxed during urination
  63. Sphrincter urethrae / muscles of the deep perineal space innervation
    pudendal nerve (S2-4) perineal branch
  64. Pelvic diaphragm
    funnel-shaped musculofibrous sheet that closes off the pelvic outlet and forms the floor of the pelvic cavity
  65. pelvic viscera
    retroperitoneal with the exception of the uterus. Pass through the pelvic floor and are anchored to it.
  66. Positions of organs in pelvic viscera
    • rectum lies POST and passes through the anal region
    • Urinary system lies anteriorly,
    • Genital system takes an intermediate position
    • both urinary and genital pass throught he urogenital region.
  67. Location of kidneys
    • lie of the POST abdominal wall embedded in perirenal fat.
    • Right kidney lies slightly lower than the left
  68. Urine flow sequence
    renal pyramids -> minor calyces -> majora calyces -> renal pelvis -> ureters -> bladder.
  69. urinary bladder
    smooth muscle sac lying behind the symphysis pubis and pubic bones
  70. what anchors the bladder
    nevck of bladder is anchored to the pubic bone by the pubovesical (female) and puboprostatic (male) ligaments
  71. Trigone
    an equilateral triangle on the interior of the posterior wall. Angles are formed y the ureteric orifices above and the interal urethral orifice below
  72. What makes up the walls of the bladder
    detrussor muscle
  73. Innervation of the bladder
    • sympathetic fibers from lower thoracis and upper lumbar segments.
    • Parasympathetic fibers - conveyed by pelvic splanchnic nerves from S2-4
  74. Sympathetic innervation to bladder
    maintain tonus of the bladder neck
  75. parasympathetic innervation of the bladder
    inhibits the bladder neck musculature and stimulate increased tonus of the detressor muscle of the bladder walls for urination
  76. Urethra
    • female - 3-4 cm long. Pierces the ANT part of the urogenital diaphragm and opens in the vestibule.
    • male - 18-20 cm long. Passes through the prostate (prostatic part), urogenital diaphragm (membranous part) and penis (spongy part)
  77. Internal urethral sphincter
    In neck of bladder. Made of smooth muscle innervated by excitatory sympathetic and inhibitory parasympathetic nerves
  78. External Urethral Sphincter
    Surrounds the membranous urethra and consists of skeletal muscle innervated by the pudendal nerve
Card Set
Pelvis and Perinuem
I put my hand up on your hip. When I dip, you dip, we dip.