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

This quiz covers the anatomy of pelvic vessels and nerves, including major arteries, internal iliac artery, and veins of the pelvis. Identify and describe the key components of the pelvic vessels and nerves.