Pelvic Vessels and Nerves Anatomy

Pelvic Vessels and Nerves

Major Arteries of the Pelvis

• Internal Iliac Artery:
  • Originates at the bifurcation of common iliac artery at vertebral level L5-S1
  • Descends inferiorly, crossing pelvic inlet to enter lesser pelvis
  • Divides into anterior and posterior trunks at the superior border of the greater sciatic foramen
• Gonadal Arteries:
  • Ovarian artery in females
  • Testicular artery in males
• Median Sacral Artery
• Superior Rectal Artery

Internal Iliac Artery Branches

• Anterior Trunk:
  • Obturator artery: supplies muscles of medial side of thigh (adductor region)
  • Umbilical artery: gives rise to superior vesical artery, which supplies superior aspect of urinary bladder
  • Inferior vesical artery: supplies lower aspect of urinary bladder
  • Vaginal artery (female): supplies inferior part of urinary bladder and rectum
  • Uterine artery (female): supplies inferior part of urinary bladder and rectum
  • Middle rectal artery: supplies distal part of rectum
  • Inferior gluteal artery: supplies gluteal muscles and hip joint
• Posterior Trunk:
  • Lateral sacral arteries: supply structures in sacral canal and skin and muscles posterior to sacrum
  • Iliolumbar artery: supplies psoas major, quadratus lumborum, and posterior abdominal wall
  • Superior gluteal artery: supplies muscles and skin of gluteal region

Veins of the Pelvis

• External Iliac Vein:
  • Continuation of femoral vein, arising when femoral vein crosses underneath inguinal ligament
  • Ascends along medial aspect of the external iliac artery
  • Receives inferior epigastric and deep circumflex iliac veins
• Internal Iliac Vein:
  • Responsible for majority of pelvic venous drainage
  • Receives numerous tributaries from veins that drain pelvic region
  • Combines with external iliac vein to form common iliac vein
• Common Iliac Vein:
  • Formed at the upper margin of pubic symphysis by the union of the external and internal iliac veins
  • Receives iliolumbar vein and median sacral veins
  • Combines at L5 to become inferior vena cava

Nerves of the Pelvis

• Sacral Plexus:
  • Definition: a network of nerve fibers that supplies the skin and muscles of the pelvis and the lower limb
  • Site: located on the anterior surface of the piriformis muscle
  • Formation: formed by anterior rami of lumbar spinal nerves L4 and L5, and sacral spinal nerves S1, S2, S3, and S4
• Branches of the Sacral Plexus:
  • Superior gluteal nerve: L4, L5, S1; motor to gluteus minimus, gluteus medius, and tensor fascia lata
  • Inferior gluteal nerve: L5, S1, S2; motor to gluteus maximus
  • Sciatic nerve: L4, L5, S1, S2, S3; major nerve of lower limb
  • Posterior femoral cutaneous nerve: S1, S2, S3; sensory supply to skin on posterior surface of thigh and leg
  • Pudendal nerve: S2, S3, S4; supplies skin and muscles of perineum
• Coccygeal Plexus:
  • Formed in pelvis by three nerve roots: fourth and fifth sacral nerves and first coccygeal nerve
  • Branches into anococcygeal nerves, which supply cutaneous innervation to anococcygeal region
• Autonomic Plexus:
  • Sympathetic: paravertebral ganglia, sacral ganglia, and ganglion impar
  • Parasympathetic: pelvic splanchnic nerves