The grey rami communicantes are unmyelinated postganglionic sympathetic fibres passing from the lumbar sympathetic ganglia back to the spinal nerves, carrying sympathetic innervation to the blood vessels, sweat glands, and arrector pili of the lower back and lower limbs. They connect each lumbar sympathetic ganglion to the corresponding ventral ramus.
| Origin | Lumbar sympathetic trunk ganglia |
|---|---|
| Course | Pass backward along the sides of the lumbar vertebral bodies, deep to the tendinous arches of psoas, to join the anterior rami of the lumbar spinal nerves, carrying postganglionic sympathetic fibres |
The grey rami communicantes carry the sympathetic fibres responsible for vasomotor and sudomotor function in the lower limbs. Lumbar sympathectomy severs these rami to produce lower limb vasodilation in peripheral vascular disease and to treat hyperhidrosis. The rami are at risk during anterior lumbar spine approaches and retroperitoneal dissection. Sympathetically maintained pain in the lower limbs involves sensitisation of these rami.
Loss of lower limb sweating from grey rami communicantes division during lumbar sympathectomy, producing compensatory hyperhidrosis in other body regions and permanent lower limb anhidrosis.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
