vessels and nerves of Pelvis | Anatomy of Pelvis | Q&A | Clinical Scenarios

Summary

This video provides an in-depth overview of the vascular and nervous anatomy of the pelvis. It begins with the arterial supply, covering the bifurcation of the common iliac arteries and the branches of both the posterior and anterior divisions of the internal iliac artery. The venous supply, including the internal iliac vein, is then discussed, followed by the formation of the sacral plexus and its associated nerves. Additionally, the video highlights important structures such as the inferior hypogastric plexus and obturator nerve, while also discussing their clinical relevance in pelvic conditions. A comprehensive guide for understanding pelvic anatomy in relation to both arteries and nerves.

Takeaways

• 😀 The descending aorta bifurcates into the left and right common iliac arteries, which further bifurcate at the pelvic brim into the external and internal iliac arteries.
• 😀 The internal iliac artery divides into a posterior and an anterior division, with the posterior division supplying the parietal regions and the anterior division supplying the pelvic organs.
• 😀 The posterior division of the internal iliac artery has three main branches: iliolumbar artery, lateral sacral artery, and superior gluteal artery.
• 😀 The iliolumbar artery supplies the iliacus muscle and iliac bone, and it forms an anastomosis with several other arteries, including the deep and superficial circumflex iliac arteries.
• 😀 The superior gluteal artery is the largest branch of the internal iliac artery and supplies the gluteal region by passing above the piriformis muscle.
• 😀 The anterior division of the internal iliac artery includes branches like the superior vesicle artery (supplying the bladder), uterine artery (in females), and the obturator artery (supplying the medial thigh).
• 😀 The inferior gluteal artery supplies the buttock and leaves the pelvis through the greater sciatic foramen below the piriformis.
• 😀 Venous blood from the pelvic region drains through the internal iliac vein, which receives tributaries from various pelvic plexuses and communicates with the vertebral venous plexus.
• 😀 The sacral plexus is formed by nerve roots from L4 to S4 and is responsible for innervating the gluteal region, thigh, and lower limbs.
• 😀 The mnemonic 'SIPPS' helps remember the nerve roots for important nerves in the sacral plexus: superior gluteal nerve, inferior gluteal nerve, pudendal nerve, posterior cutaneous nerve of the thigh, and sciatic nerve.
• 😀 The inferior hypogastric plexus is a key autonomic plexus supplying the pelvic organs with sympathetic and parasympathetic fibers, contributing to organ function and sensation.

Q & A

What is the primary function of the internal iliac artery?

The internal iliac artery supplies blood to the pelvic organs, gluteal region, and perineum. It divides into the posterior and anterior divisions, each providing branches that supply different pelvic structures.

What are the key branches of the posterior division of the internal iliac artery?

The key branches of the posterior division are the iliolumbar artery, lateral sacral artery, and superior gluteal artery. These arteries supply the pelvic wall, sacrum, and gluteal region.

What does the iliolumbar artery supply?

The iliolumbar artery supplies the iliacus muscle and iliac bone. It also forms an anastomosis with several other arteries, including the deep circumflex iliac artery, the lateral circumflex femoral artery, and the superior gluteal artery.

How does the inferior vesical artery differ in males and females?

In males, the inferior vesical artery supplies the lower bladder, ureter, vas deferens, and prostate. In females, it corresponds to the vaginal artery, supplying the upper vagina.

What is the role of the uterine artery in female pelvic circulation?

The uterine artery supplies the uterus, uterine tubes, and anastomoses with the ovarian artery. It plays a crucial role in supplying blood to the reproductive organs.

How does the venous supply of the pelvic region differ from its arterial supply?

The venous supply of the pelvic region involves the internal iliac vein, which receives tributaries corresponding to the pelvic arteries. Pelvic veins are unique because they lack valves, making them susceptible to retroperitoneal hemorrhage, especially after pelvic fractures.

What is the significance of the sacral plexus in the pelvic region?

The sacral plexus is a network of nerves that originates from the nerve roots L4 to S4. It supplies the muscles and skin of the pelvic region, gluteal region, and lower limbs, playing a key role in motor and sensory innervation.

Which nerve roots contribute to the formation of the sciatic nerve?

The sciatic nerve is formed by the nerve roots L4, L5, S1, S2, and S3. It supplies the lower limb and is one of the largest nerves in the body.

What is the role of the inferior hypogastric plexus?

The inferior hypogastric plexus is an autonomic nerve plexus that lies lateral to the rectum. It is involved in the sympathetic and parasympathetic innervation of pelvic organs, including the bladder, rectum, and reproductive organs.

How does the obturator nerve contribute to pelvic function?

The obturator nerve, arising from the lumbar plexus (L2-L4), supplies the medial thigh muscles and plays a key role in the adduction of the thigh. It also passes near the ovary, making it a point where pain from the ovary can be referred to the inner thigh.