Changes

==Blood Supply==

==Blood Supply==

The epineurium is penetrated by the vascular supply to the nerve and this blood supply is known as the '''vasa nervorum'''. Only capillaries occur within the endoneurial compartment. The capillaries of the endoneurium are joined by tight junctions and provide a barrier to large macromolecules. This forms the basis of the blood-nerve barrier (BNB), which has similarities to the [[Blood Brain Barrier - Anatomy & Physiology|blood-brain barrier]] of the CNS. The BNB appears to be relatively weak in the sensory ganglia because fenestrations occur between endothelial cells in this location. Sensory ganglia are therefore more vulnerable to blood-borne agents.  A further "barrier" is provided by the perineurium which consists of sheets of flattened cells, connected by tight junctions and covered on both sides by a basal lamina. The only route across this structure is trans- rather than inter-cellular.

The epineurium is penetrated by the vascular supply to the nerve and this blood supply is known as the '''vasa nervorum'''. Only capillaries occur within the endoneurial compartment. The capillaries of the endoneurium are joined by tight junctions and provide a barrier to large macromolecules. This forms the basis of the blood-nerve barrier (BNB), which has similarities to the [[Blood Brain Barrier - Anatomy & Physiology|blood-brain barrier]] of the CNS. The BNB appears to be relatively weak in the sensory ganglia because fenestrations occur between endothelial cells in this location. Sensory ganglia are therefore more vulnerable to blood-borne agents.  A further "barrier" is provided by the perineurium which consists of sheets of flattened cells, connected by tight junctions and covered on both sides by a basal lamina. The only route across this structure is trans- rather than inter-cellular.