EVERYDAY SCIENCE

Detailed explanation-1: -The white ramus communicans (pl. white rami communicantes), which is also known as the white communicating branch or the white communicating ramus, contains preganglionic fibers of the sympathetic system. The white ramus communicans is a structure that anteriorly connects the spinal nerve to the sympathetic trunk.

Detailed explanation-2: -Sympathetic Nervous System The axon from the intermediate horn of spinal cord migrates toward the sympathetic ganglia by passing through the ventral root of spinal nerve to reach the sympathetic ganglia via white rami communicantes. These are known as preganglionic fibers and are myelinated.

Detailed explanation-3: -The sympathetic chain is a ganglionated chain present bilaterally extending from the base of the skull to the coccyx. It divides into cervical, thoracic, lumbar and sacral segments. The two side chains fuse at the ganglion in front of the sacrococcygeal junction.

Detailed explanation-4: -The rami communicantes, which translate as ‘communicating branches’, are responsible for relaying autonomic signals between the spinal nerves and the sympathetic trunk. Spinal nerves can have a grey ramus communicans and a white ramus communicans. Grey rami communicantes exist at all levels of the spinal cord.

Detailed explanation-5: -The grey rami communicantes exist at every level of the spinal cord and are responsible for carrying postganglionic nerve fibres from the paravertebral ganglia to their destination, and for carrying those preganglionic nerve fibres which enter the paravertebral ganglia but do not synapse.