Pelvic Vessels and Nerves Flashcards
What is the main artery that supplies all the organs of the pelvic cavity
Internal iliac artery that contains both an anterior and posterior division
what are the arteries off the posterior division of the internal iliac artery and what do they supply
Lateral sacral arteries: can be two or more vessels
-can enter the anterior sacral foramina to supply the structures of the sacral canal, and eventually exit the posterior sacral foramina to supply the muscles and skin posterior to the sacrum
Iliolumbar artery: courses between the obturator nerve and the lumbosacral trunk to supply the iliacus muscel and lumbar region posterior to the psoas maor muscle
Superior gluteal artery: the terminal branch, exits the greater sciatic foramen superior to the piriformis to supply the gluteal region
What are the 8 arterial divisions of the anterior division of the anterior division of the internal iliac artery?
1) umbilical artery that is obliterated after birth
2) Superior vesical artery: supplies the bladder and originates from the same trunk as the umbilical artery
3) The inferior vesical artery: supplies the bladder, seminal vesicle, prostate, ureter and vas deferens
- found only in males
4) The middle rectal artery that supplies the rectum, prostate, seminal vesicle, vas deferens and the vagina in the female
5) The obturator artery: leaves the pelvis via the obturator canal to enter the medial thigh
- supplies the head of the femur, medial thigh, and pelvic muscles
6) Internal pudendal artery: exits the pelvis via the greater sciatic foramen and loops around the spine of the ischium to enter the perineum via the lesser sciatic foramen
- supplies the inferior rectal artery and it gives branches to the vagina
7) inferior gluteal artery: exits the greater sciatic foramen inferior to the piriformis to supply the gluteal region
8) Uterine artery: supplies the uterus and vagina and ultimately anastamoses with the ovarian artery
- only in females
9) found only in 20 percent of the population: Accessory obturator artery
Characteristics of the Pelvic veins?
THese veins correspond to the branches of the internal iliac artery
each pelvic organ has a venous plexus which freely communicates with the other venous plexuses
These venous plexuses have no valves and have important connections with the vertebral venous plexus (batsons veins)
What artery comes off the inferior Mesenteric A that supplies the pelvic area?
Superior rectal Artery:
- Divides at S3 into two branches
- each branch descends on either side of the rectum to supply it as far inferiorly as the internal anal sphincter
where does the common iliac artery bifurcate?
L5-S1 intervertebral disc
Names of the Pelvic veins and their characteristics
Pelvic venous plexusues:
-associated with the pelvic viscerea and drained by tributaries of internal iliac veins, inferior mesenteric vein and lateral sacral veins
Internal iliac veins
- form superior to the greater sciatic foramen and lie postero-inferior to the internal iliac arteries
- merge with external iliac veins to form the common iliac veins, which unite at iliac L4/L5 to form inferior vena cava
Lateral sacral veins:
- anastomose with internal vertebral plexus providing a collateral pathway to reach either the inferior or superior vena cava
- may also provide a metastatic pathway for prostatic cancer cells to the vertebrae or cranial cavity
Superior rectal vein:
-tributary to inferior mesenteric vein
Superior gluteal veins:
-largest tributaries to the internal iliac veins
Testicular veins: exit deep inguinal ring and traverse pelvic cavity to travel to their destinations
what are the pelvic structures mainly innervated by?
Sacral plexus
Coccygeal plexus
Pelvic autonomic nerves
Pelvic splanchnic nerves
What are the 4 nerves of the sacral plexus and what are their innervations
Sciatic Nerve (L4-S3)
- passes inferior to the piriformis to enter the gluteal region
- descends in the posterior thigh to supply the posterior compartment of the thigh and the entire leg and foot
Pudendal Nerve (S2-S4):
- passes between the piriformis and coccygeus muscles accompanied by the internal pudendal artery
- pudendal nerve enters the perineum through the lesser sciatic foramen to supply the perineum
Superior gluteal nerve (L4-S1)
-Passes superior to the piriformis to enter the gluteal region to supply the gluteus medius and gluteal minimus
Inferior gluteal nerve (L4-S2)
-passes superior to the piriformis to enter the gluteal region to supply the gluteus maximus
What does the coccygeal plexus innervate?
Anterior rami of S4, S5 ,and CO
- lies on th pelvic surface of the coccygeus muscle
- supplies the coccygeus muscle part of the levator ani muscle and the sarcococcygeal joint
- anococcygeal nerves arise from the plexus to supply the skin between the tip of the coccyx and the anus
Characteristics of the Inferior hypogastric plexuses and sub plexuses
Inferior hypogastric plexus supplies the sympathetic innervation to pelvic viscera
-branches of the inferior hypogasatric plexus continue to the pelvic viscera upon which they form the subplexuses collectively known as pelvic plexuses
In both male and female, sub-plexuses are associated with the lateral rectum and inferolateral urinary bladder
in males: sub-plexuses are associated with the prostate gland and the seminal vesicle
Parasympathetic fibers in the prostatic plexus penetrate the pelvic diaphragm to reach the erectile tissues in the penis producing an erection
In females: sub plexuses are associated with the cervix of the uterus and lateral fornices of the vagina
what are the pelvic splanchnic nerves?
S2-S4 that supply the parasympathetic innervation to the pelvic viscera plus the descending colon, sigmoid colon, rectum and proximal anal canal
Four groups of lymph nodes and what do they drain?
External iliac lymph nodes:
- receive lymph from the inguinal nodes and superior parts of middle to anterior pelvic organs
- they drain to the common iliac nodes
Internal iliac nodes:
- receive lymph from inferior pelvic viscera, deep perineum, and gluteal region
- they drain into the common iliac nodes
Sacral lymph nodes:
- receive lymph from postero-inferior pelvic viscera
- they drain into internal or common iliac nodes
Common iliac lymph nodes:
- receive lymph from three previous groups of nodes
- they drain into the lumbar nodes
Innervation of the Anal Canal
Superior to the pectinate line
- sympathetic via lumbar and sacral splanchnic nerves
- Parasympathetic via pelvic splanchnic nerves
- below pelvic pain line: both visceral pain and visceral non-pain are conveyed via pelvic splanchnic nerves
Inferior to pectinate line
-somatic innervation via inferior rectal nerves (branches or pudendal nerve)
