<prompt> Structures preserved in functional radical dissection of the neck -a Int. jugular veinb Sternomastoidc Lymph nodesd Accessory nerveabcbcdabdacd  <response>: Functional dissection is modified radical neck dissection MRND Type III Modified radical neck dissection is done only selected cases where tumor is very well differentiated and less aggressive like in papillary carcinoma of thyroid with lymph node secondaries . Structures preserved here are sternomastoid muscle , internal jugular vein and spinal accessory nerve . Ref - Srbs manual of surgery 5e p450 