Lecture 28: Pelvic Vessels, Nerves and Lymphatics Flashcards
Be able to draw the following: abdominal and pelvic arteries branches of the uterine a. rectum blood supply Pelvic nerves
Ok
Common Iliac bifurcates at _____ into _____ and _______
L5- S1 vertebrae; External Iliac A (becomes femoral A.).; Internal Iliac A. (branches to the pelvis and perineum)
What consists the posterior division of the Internal Iliac A.?
Posterior division:
Iliolumbar A.
Lateral Sacral A.
Superior Gluteal A.
What do these arteries supply?
Iliolumbar
Lateral Sacral
Superior Gluteal
- iliacus, psoas major, QL, cauda equina in vertebral canal
- piriformis, spinal meninges, root of sacral spinal nerves, erector spinae and skin covering dorsal sacrum
- piriformis, gluteal muscles, tensor fascia lata
What consists the anterior division of the Internal Iliac A.?
Umbilical A. Obturator A Accessory obturator A. (20% of patients) Inferior vesical artery (males) Uterine atery (females) Vaginal artery (females) Middle rectal A. Internal pudendal A. Inferior gluteal A.
What do these arteries supply?
- Umbilical A.
- Obturator A
- urinary bladder
2. pelvic muscles, head of femur, medial thigh
- Inferior vesical artery (males)
- Uterine atery (females)
- Vaginal artery (females)
- urinary bladder, ureter, prostate, seminal vesicles
- uterus and ligaments, uterine tube, ovary, superior vagina
- anterior and posterior vaginal surfaces
6 Middle rectal A.
- Internal pudendal A.
- Inferior gluteal A.
- rectum, seminal vesicles, prostate
- perineum
- pelvic muscles, piriformis, QF, gluteus maximus, sciatic nerve
Course of the superior rectal A.
Origin: Inferior Mesenteric A. > bifurcates at S3 > each branch descends on either side of the rectum (as far down as internal anal sphincter)
What venous system drains the pelvic viscera?
What drains this system?
- Pelvic Venous Plexus
- tributaries of the internal iliac veins, inferior mesenteric vein (superior rectal vein) and lateral sacral veins
How does blood from the pelvic venous plexus return to the vena cavas?
- Lateral sacral veins have anastomosis with internal vertebral plexus to bring blood to the VCs
- cancer cells can travel to vertebrae from prostate/ovary through this pathway
What parts of the pelvic viscera do these nodes drain?
External iliac lymph nodes
Internal iliac lymph nodes
Sacral lymph nodes
- takes lymph from the inguinal nodes and superior parts of middle and anterior pelvic organs
- inferior pelvic viscera, deep perineum, and gluteal region
- postero-inferior pelvic viscera
- All drain to the common iliac nodes
What plexus innervates the pelvic structures?
Somatic: sacral and coccygeal spinal nerves
ANS: lumbar, sacral and pelvic splanchnic nerves (via hypogastric plexuses)
What nerves exit through the Greater sciatic foramen?
Sciatic n. (L4-s3)
Pudendal N. (s2-s4)
Superior gluteal N. (L4-S1)
Inferior gluteal N. (L4-s2)
What do these nerves supply and anatomic significance?
Sciatic nerve
Pudendal nerve
- posterior thigh and entire leg and foot, passes inferior to piriformis
- perineum, enters with internal pudendal artery into lesser sciatic foramen
What do these nerves supply and anatomic significance?
Superior gluteal nerve
Inferior gluteal nerve
- gluteus medius and minimus,
- gluteus maxiumus
*both pass superior to piriformis
What is the coccygeal plexus and what does it supply?
- anterior rami of S4, S5 and coccyx
- supplies coccygeus muscle, part of levator ani and sacrococcygeal joint
What are anococcygeal nerves?
-arise from the coccygeal plexus and supplies the skin between tip of coccyx and anus
What supplies sympathetic innervation to pelvic viscera?
What supplies parasympathetic innervation to pelvic viscera?
Lumbar and sacral splanchnic nerves - synapse at hypogastric plexuses
Pelvic splanchnic nerves - S2-4 (also PNS to descending colon and distal structures)
What are the main sympathetic contributors to the pelvic viscera?
- ) Lumbar splanchnic nerves > synapse at superior hypogastric plexus > ureter/testes OR synapse at inferior hypogastric plexus to pelvic plexuses that innervate visceral targets
- ) Sacral splanchnic nerves > synapse at inferior hypogastric plexus > rectal/vesical plexus to various pelvic targets
What is the pathway of parasympathetic innervation to viscera?
Pelvic splanchnic nerves (S2-s4) > synapse at inferior hypogastric plexus > post ganglionics to pelvic viscera
What are sub-plexuses and how are they similar/different in males/females?
refers to branches of the inferior hypogastric plexus that carries signals to various pelvic organs
Similarity in male/female: both associated with lateral rectum and inferolateral urinary bladder
Male: associated with prostate and seminal vesicles, penetrate the pelvic diaphragm to reach the erectile structures
Female: associated with the cervix and lateral fornices
