Pelvis anatomy Flashcards
Obturator internus
Supplied by L5 and S1, attaches to GT of femur
Lateral rotation of femur and abduction of flexed hip
Piriformis
Supplied by S1 and S2, attaches to GT of femur above obturator internus
Lateral rotation of femur and abduction of flexed hip
Separates greater sciatic foramen into two regions (one above and one below)
Obturator canal
Bordered by obturator membrane, associated obturator muscles and superior pubic ramus. Obturator nerve and vessels pass from pelvic cavity to the thigh through this canal.
Greater sciatic foramen
Formed by greater sciatic notch, sacrotuberous and sacrospinous ligaments and spine of ischium.
Superior gluteal nerves and vessels passes through foramen above piriformis
Inferior gluteal nerves and vessels, sciatic nerve, pudendal nerve, internal pudendal vessels, posterior femoral cutaneous nerves and nerves to obturator internus and quadratus femoris muscle passes below piriformis
Lesser sciatic foramen
Formed by lesser sciatic notch, ischial spine, sacrospinous ligament, sacrotuberous ligament.
Tendon of obturator internus passes through this foramen to enter gluteal region.
Below attachment of pelvic floor, act as route of communication between perineum and gluteal region.
Pudendal nerve and internal pudendal vessels pass through here as well + greater sciatic foramen
Pelvic floor
Formed by pelvic diaphragm, perineal membrane and muscles in deep perineal pouch
Greater sciatic foramen above pelvic floor
Lesser sciatic foramen below pelvic floor
Pelvic diaphragm
Levator ani (iliococcygeus, pubococcygeus and puborectalis) and coccygeus muscles from both sides Innervated by branches of anterior ramus of S4 and branches of pudendal nerve S2-S4
External urethral sphincter
All muscles in deep perineal pouch
Innervated by perineal branches of pudendal nerve
Ureters
Enters pelvic cavity anterior to bifurcation of common iliac artery and joins base of bladder.
Crossed by
uterine artery in women
ductus deferens in men
Bladder
Retroperitoneal structure
apex, two inferolateral surfaces, base and superior surface
Neck is most fixed part of the bladder. Anchored onto posteroinferior aspect of pubic bone by pubovesical ligaments (women) or puboprostatic ligaments (men)
Deep perineal pouch
Space between pelvic diaphragm (superior) and perineal membrane at the bottom
Bladder cancer spreads via
internal iliac lymph nodes
Urethra in women
Short, about 4cm.
Urethra in men
Long, about 20cm, bends twice along its course.
Preprostatic, prostatic, membranous and spongy.
Preprostatic part of urethra
1cm long, associated with internal urethral sphincter
Prostatic part
3-4cm long, site of connection between reproductive and urinary part of men
membranous part
passes through deep perineal pouch.
Surrounded by external urethral sphincter
Spongy part
longest part of urethra