PELVIC BLOOD SUPPLY

Iliac Arteries Common iliac: External iliac: Travels lateral to superior pubic ramus. Branches: Deep circumflex iliac artery. Inferior epigastric artery: Travels deep to inguinal ligament. Becomes femoral artery: Moore, Fig. 3.11.

Iliac Arteries Common iliac: Internal iliac: Travels inferiorly and medially over pelvic brim. Supplies: Pelvic organs. Gluteal muscles. Perineum. Two divisions: Anterior. Posterior.

Internal Iliac Arteries Anterior division: Umbilical artery: Gives off superior vesicle arteries: Supplies superior aspect of urinary bladder. Becomes either: Obliterated umbilical artery. Medial umbilical artery.

Internal Iliac Arteries Anterior division: Obturator artery: Travels anteriorly and inferiorly along pelvic wall. Exits pelvic cavity through: Obturator canal (in obturator foramen). Supplies: Pelvic muscles. Ilium. Femoral head. Muscles of medial thigh.

Internal Iliac Arteries Anterior division: Inferior vesicle artery (male): Travels inferiorly and posteriorly to urinary bladder. Analogous to female uterine artery. Prostatic branch: Supplies prostate gland. Artery to ductus deferens.

Internal Iliac Arteries Anterior division: Uterine artery (female): Travels medially in broad ligament. Analogous to male inferior vesicle artery. Supplies uterus and vagina.

Internal Iliac Arteries Anterior division: Internal pudendal artery (male): Exits pelvic cavity through greater sciatic foramen. Loops around ischial spine. Enters perineum through lesser sciatic foramen. Enters pudendal canal.

Internal Iliac Arteries Anterior division: Internal pudendal artery (male): Branches: Inferior rectal. Perineal artery: Posterior scrotal artery. Artery of bulb of penis. Deep artery of penis: Supplies corpora cavernosa of penis. Dorsal artery of penis.

Internal Iliac Arteries Anterior division: Internal pudendal artery (female): Branches: Inferior rectal. Perineal artery: Posterior labial artery. Artery of vestibule of vagina. Deep artery of clitoris. Dorsal artery of clitoris.

Internal Iliac Arteries Anterior division: Inferior gluteal artery: Exits pelvic cavity through greater sciatic foramen. Usually passes inferior to piriformis muscle. Supplies: Coccygeus muscle. Three levator ani muscles. Piriformis and quadratus femoris muscles. Uppermost posterior thigh muscles. Gluteus maximus. Sciatic nerve.

Internal Iliac Arteries Anterior division: Middle rectal artery: Travels inferior to lower rectum. Supplies lower rectum and seminal vesicles in males.

Internal Iliac Arteries Posterior division: Iliolumbar artery: Travels posterior to sacroiliac joint posterior to common iliac vessels and psoas major muscle. Supplies; Psoas major muscle. Iliacus muscle. Quadratus lumborum muscle. Cauda equina (in vertebral canal).

Internal Iliac Arteries Posterior division: Lateral sacral artery: Travels on anteromedial aspect of piriformis muscle. Sends branches to ventral sacral foramina. Supplies: Piriformis muscle. Sacral canal structures. Erector spinae muscles.

Internal Iliac Arteries Posterior division: Superior gluteal artery: Exits pelvic cavity through greater sciatic foramen superior to piriformis muscle. Supplies: Piriformis muscle. Gluteus medius muscle. Gluteus minimus muscle. Tensor fascia latae muscle.

Abdominal Aorta Branches to pelvis: Testicular (male): Travels through inguinal canal into scrotum. Travels inside spermatic cord. Supplies testis.

Abdominal Aorta Branches to pelvis: Ovarian (female): Travels inferiorly over pelvic brim to ovary: Through suspensory ligament.

Abdominal Aorta Branches to pelvis: Inferior mesenteric: Superior rectal artery: Travels over left common iliac vessels into pelvic cavity. Supplies superior aspect of rectum. Anastomoses with middle and inferior rectal arteries.

Abdominal Aorta Branches to pelvis: Median sacral: From posterior aspect of termination of aorta. Travels in median plane over L4-5, sacrum, coccyx.

Veins Most analogous and named for corresponding arteries. Pampiniform plexus: Inside spermatic cord. Drains testicular vein.

Veins Internal rectal venous plexus: External rectal venous plexus: Superior-most anastomosis of the three rectal veins. External rectal venous plexus: Inferior-most anastomosis of the three rectal veins. Near anus.

Internal Hemorrhoids “Piles” Prolapse of mucosa containing internal rectal venous plexus. Pain and impeded blood flow.

External Hemorrhoids Produced by blood clots in external rectal venous plexus. Bulging out of skin and mucosa from external rectal venous plexus.

PELVIC INNERVATION

Sacral Plexus L4-S4: Superior gluteal nerve (L4-S1): To gluteus medius and minimus. Inferior gluteal nerve (L5-S2): To gluteus maximus. Moore, Fig. 3.10 and Table Figure 3.4

Sacral Plexus Muscular branches: Quadratus femoris (L4-S1). Obturator internus (L5-S2). Piriformis (S1-2). Levator ani and coccygeus (S3-4).

Sacral Plexus Posterior femoral cutaneous (S1-S3): To buttock and uppermost region of posterior thigh.

Sacral Plexus Pudendal (S2-4): To perineum: Inferior rectal nerve: Innervates anal canal. Dorsal nerve of penis. Perineal nerve: Posterior scrotal nerve.

Sacral Plexus Sciatic nerve (L4-S3): Passes through greater sciatic foramen. Tibial nerve (L4-S3). Common peroneal nerve (L4-S2).

Coccygeal Plexus S4, S5, coccygeal nerve. Anococcygeal nerve.

Lumbar Plexus (T12) L1-5. Ilioinguinal nerve: Lateral to psoas major. Anterior scrotal nerve (male): To scrotum. Labial branch (female): To labia majora.

Lumbar Plexus Genitofemoral nerve (L1-2): Lumbosacral trunk (L4-5). Anterior to psoas major. Genital branch: To scrotum (male). To labia majora (female). Lumbosacral trunk (L4-5).

Sympathetic System Lumbar splanchnic nerves: Sympathetic. From lumbar plexus to: Abdominal sympathetic plexus. Inferior mesenteric ganglion. Superior hypogastric plexus: To uterine tubes in female.

Sympathetic System Sacral splanchnic nerves: Sympathetic. From sacral plexus. Feed into sacral sympathetic trunk and then into inferior hypogastric plexus.

Sympathetic System Sacral sympathetic trunk: Paravertebral ganglia. Ganglion impar: Coccygeal ganglion. Superior hypogastric: Sympathetic. From lumbar and sacral splanchnic nerves. Feed into inferior hypogastric plexus.

Sympathetic System Sacral sympathetic trunk: Paravertebral ganglia. Inferior hypogastric plexus: Mixed parasympathetic. In males innervates urethra, ductus deferens, prostate gland, and ejaculatory ducts. In females, innervates urethra and produces uterovaginal plexus. Produces vesicle plexus (urinary bladder). Supplies rectum. Uterovaginal plexus (uterus, vagina, ovaries.

Parasympathetic System Pelvic splanchnic nerves Parasympathetic. S2-4. Feed into inferior hypogastric plexus.

Parasympathetic System Inferior hypogastric plexus: In females: Innervates: Urethra. Rectum. Produces: Uterovaginal plexus (uterus, vagina, ovaries).