Module 10 - Pelvis Flashcards
Bony pelvis (pelvic girdle) description
“Ring of bone” formed by R/L hip bones, sacrum, coccyx
Function of pelvic girdle
Supports abdomen
Provides dynamic link between vertebral column and lower limbs
Iliopectineal line (pelvic brim)
Divides the pelvis into pelvic major (false) and pelvic minor (true)
Hip bones
Ilium
Ischium
Pubis
Landmarks of Ilium
Body, iliac crest, iliac tubercle ASIS, AIIS, PSIS, PIIS Auricular surface Arcuate line Iliopectineal line Greater sciatic notch
Landmarks of Ischium
Body Ischial spine Lesser sciatic notch Ischial tuberosity Ramus
Landmarks of Pubis
Superior and inferior pubic rami Pubic symphysis, crest, tubercle Pectin pubis (pectineal line) Iliopectineal line Obturator canal
Landmarks of Sacrum
Base (superior portion) Apex (inferior portion) Median and lateral sacral crests Ala Promontory Sacral cornu, hiatus
Pelvis apertures
Superior (pelvic inlet/brim) - sacrum, ilium, pubis
Inferior (pelvic outlet) - diamond shaped
Superior pelvic aperture (inlet) - posterior, lateral, anterior boundaries
Posterior: promontory and anterior border of ala of sacrum (sacrum)
Lateral: ilipectineal line (illium)
Anterior: pubic symphysis, pectin pubis, pubic crest (pubic)
Pelvis major
“False” pelvis
Region above iliopectineal line
Pelvis minor
“True” pelvis
Region below iliopectineal line
Inferior pelvic aperture (outlet) - posterior, lateral, anterior boundaries
Posterior: sacrum and coccyx
Lateral: ischial tuberosities, sacrotuberous ligaments
Anterior: pubic symphysis, arcuate ligament, rami of pubis and ischium
*Pelvic “floor”
Pelvis major contains:
Ileum of small intestine
Sigmoid colon
Pelvis major boundaries
Abdominal wall, iliac fossae, L5/S1
Pelvis minor contains:
Urinary and reproductive organs
Pelvis minor boundaries
Pelvic surfaces of hip bones, sacrum and coccyx
Acetabulum is formed by:
Junction of 3 hip bones (ischium, ilium, pubis)
Acetabulum features
Acetabular notch, lunate, margin
T/F: Acetabulum is round in females
FALSE, it is round in males
Obturator foramen is formed by:
Rami of pubis and ischium
What passes through obturator foramen?
Obturator nerve, blood vessels
Joints of the pelvis:
Sacroiliac
Pubic symphysis
Sacroiliac joint type
Synovial, irregular plane with “ear shaped” auricular surfaces
Sacroiliac joint ligaments
Posterior, interosseous, anterior SI ligaments
Movements at the sacroiliac joint
Slight gliding and rotation
*Research agrees that there is movement, but disagrees on magnitude/direction
Pubic symphysis joint type
Fibrocartilaginous
T/F: Interpubic disc of pubic symphysis is thicker in males
FALSE, it is thicker in females
Ligaments of the pubic symphysis
Superior pubic - connects superior pubic bodies, R/L tubercles
Inferior pubic - arcuate ligament
Vertebropelvic ligaments
Iliolumbar
Sacrotuberous
Sacrospinous
Ligaments of sacroiliac joint
Iliolumbar ligament
L4/5 to iliac crest
Sacrotuberous ligament
Lateral sacrum/coccyx/PIIS to ischial tuberosity
Sacrospinous ligament
Caudal border of sacrum to ischial spine
Ligaments of sacroiliac joint
Posterior and interosseous = very strong
Anterior = thin
Anterior pelvic wall
Bodies and rami of pubic bones, obturator internus muscle/fascia, pubic symphysis
Lateral pelvic wall
Obturator internus muscle, obturator nerves and vessels, branches of internal iliac vessels
Obturator internus attachments
Ilium/ischium + greater trochanter femur
Obturator internus innervation
Nerve to obturator internus (L5-S2)
Obturator internus actions
External rotation of femur
Stabilize head of femur
Piriformis attachments
Sacrum/greater sciatic notch + greater trochanter femur
Piriformis innervation
Ventral rami of S1-S2
Piriformis actions
External rotation, abduction of femur
Stabilize head of femur
Posterior pelvic wall
Sacrum and adjacent parts of ilium
Sacroiliac joints and their ligaments
Piriformis muscle
Sacral plexus and internal iliac vessels
Piriformis syndrome
Myofascial trigger points
Potential for entrapment of sciatic nerve
Pelvic diaphragm consists of:
Levator ani and coccygeus muscles
Levator ani function
Supports pelvic viscera
Resists intra-abdominal pressure
Levator ani parts
Puborectalis
Pubococcygeus
Iliococcygeus
Puborectalis
U-shaped, lasso around anorectal junction
Pubococcygeus
Main part of levator ani
Levator ani attachments
Body of pubis/obturator membrane/ischial spine + coccyx/walls of prostate or vagina/rectum/anal canal
Levator ani actions
- Raise pelvic floor (assisting in compression of abdominal/pelvic contents)
- Voluntary control of urination, fecal incontinence
Pelvic floor consists of:
Levator ani
Ischiococcygeus (small portion of pelvic floor)
Ischiococcygeus attachments
Ischial spine to coccyx and lower sacrum
Ischiococcygeus actions
Assists levator ani in supporting pelvic viscera, flex coccyx
Blood vessels of pelvis
Common iliac External iliac Internal iliac Superior rectal Median sacral Gonadal
Common iliac artery bifurcates at:
L4
External iliac artery passes through ______ only
False pelvis
External iliac artery runs along _____
Medial border of psoas
Branches of external iliac artery:
Inferior epigastric
Deep circumflex
External iliac artery exits _____ deep to _____ and becomes ______
False pelvis
Inguinal ligament
Femoral artery
Internal iliac artery descends in pelvis to ______ where it divides into _____
Greater sciatic foramen
Anterior and posterior divisions
Posterior division of internal iliac artery and what they supply
- Superior gluteal: piriformis, 3 glutes, TFL
- Iliolumbar: psoas, iliacus, quadratus lumborum
- Lateral sacral: piriformis, sacral canal, erector spinae
Anterior division (visceral branches) of internal iliac artery and what they supply
- Umbilical: superior bladder
- Superior vesical: superior bladder, pelvic part of ureter
- Inferior vesical (male): inferior bladder, ductus deferens, prostate
- Vaginal: inferior bladder, vagina
- Uterine: uterus, ligament of uterus, vagina
- Middle rectal: seminal vesicles, lower rectum
- Internal pudendal: perineum
- Obturator: pelvic muscles, femur head, medial thigh muscles
- Inferior gluteal: pelvic diaphragm, piriformis, quadratus femoris, upper hamstrings, glut max, sciatic nerve
Superior rectal artery supplies:
Upper portion of rectum
*Branch of inferior mesenteric artery
Median sacral artery supplies:
Lower lumbar vertebrae, sacrum, coccyx
*Branch of abdominal aorta
Gonadal arteries
Ovarian (female)
Testicular (male)
*Branches of abdominal aorta
Nerves of the pelvic region
Lumbar plexus
Sacral plexus
Lumbar plexus is formed by:
Ventral primary rami of L1-L4
Roots of the lumbar plexus split into _____ within the _____ muscle
Anterior and posterior divisions
Psoas
Terminal branches of the lumbar plexus
Iliohypogastric Ilioinguinal Lateral femoral cutaneous Femoral Obturator Genitofemoral Branch to lumbosacral trunk
Ilioinguinal and iliohypogastric nerves
- L1
- Pass inferolateral and anterior to quadratus lumborum
- Supply skin to suprapubic and inguinal regions
- Motor supply to abdominals
Lateral femoral cutaneous nerve
- L2, L3
- Cutaneous supply to anterior and lateral thigh
Femoral nerve
- L2 thru L4
- Posterior divisions
- Supply hip flexors and extensors of knee
- Lateral to BV as it enters thigh deep to inguinal ligament
Obturator nerve
- L2 thru L4
- Anterior divisions
- Supply adductors of thigh
Genitofemoral nerve
- L1, L2
- Pierces anterior surface of psoas
- Divides into genital and femoral branches (cutaneous anterior thigh)
Branch to lumbosacral trunk
- L4
- Contributes to formation of sacral plexus
Sacral plexus is formed by:
Lumbosacral trunk (L4, L5) and ventral primary rami of S1-S4
Sacral plexus runs ______ into _____ region through the ______
Inferolaterally
Gluteal
Greater sciatic foramen
Sacral plexus supplies:
- Musculature and skin of buttocks
- Posterior compartment of thigh
- Entire leg and foot below the knee
Anterior division branches of sacral plexus
Nerve to quadratus femoris
Nerve to obturator internus
Pudendal
Nerves to levator ani and coccygeus
Posterior division branches of sacral plexus
Superior gluteal
Inferior gluteal
Perforating cutaneous nerve
Nerve to piriformis