The vagus nerve is part of the group of cranial nerves responsible for innervation of structures derived from the branchial arches. It is also part of a group together with the glossopharyngeal and accessory nerves that passes through the jugular foramen which is termed the vagus group.ranial nerves are those nerves which arise from the brain and brain stem rather than the spinal cord. Nerves arising from the spinal cord are the peripheral nerves. There are 12 pairs of cranial nerves and these pairs of nerves passage through foramina in the skull, either individually or in groups.
Resistivity and conductivity are reciprocals: Ï = 1 / Ï {\displaystyle \rho =1/\sigma } . Resistivity is a measure of the material's ability to oppose electric current. This formula is not exact, as it assumes the current density is totally uniform in the conductor, which is not always true in practical situations.
Where R is resistance in ohms, L is the length of the wire in meters, A is the cross sectional area of the wire in square meters, and Ï is the electrical resistivity in ohm-meters. Electrical conductivity is the inverse of resistivity: itâs the ability of a material to let current pass through.