There are 4 main apertures that connect the lower limb to the abdomen/perineum/pelvis:
1/ Greater Sciatic Foramen
2/ Lesser Sciatic Foramen
3/ Obturator Canal
4/ Deep to the inguinal Ligament
'1. Deep to the inguinal ligament
Conveys structures from the pelvis to the lower limb.
- Muscles: iliacus, Psoas, pectineus
- Nerves: Femoral Nerve, Femoral branch of the genitofemoral nerve, lateral cutaneous nerve of thigh.
- Vessles: femoral artery, femoral vein.
2. Greater sciatic foramen:
conveys structures from the pelvis to the gluteal region.
- Muscle: piriformis
3. Obturator canal
This canal is formed between the bone at the top of the obturator foramen and the obturator membrane, which closes most of the foramen.
4. Lesser Sciatic Foramen
- For structures passing between the perineum and gluteal region through the lesser sciatic foramen.
- Tendon of the obturator internus muscle
- The nerve and artery of the perineum (the internal pudendal artery and pudendal nerve) pass out of the pelvis through the GSF into the gluteal region and then immediately pass around the ischial spine and sacrospinous ligament and through the lesser sciatic former to enter the perineum.
Stat Dx. https://my.statdx.com/treenode/anatomy/797a02d4-38b4-4fb8-b8c9-f9f530385d13
Moore's Anatomy 2nd ed.