<prompt> Tracheostomy opening is put on...tracheal rings:2-Jan3-Feb7-Apr6-May  <response>: Ans: b 2 - 3 rings Ref:Dhingra, 3rd ed, p. 382 4ed, p. 292Tracheostomy: Making an opening in the anterior wall of trachea converting it into a stoma on the skin surfaceTracheotomy: Means opening the trachea, a step in tracheostomy operationTracheostomy can be divided into 3 types:HighMidLowHigh tracheostomy:Above the level of thyroid isthmusIsthmus lies against II. III. IV tracheal ringsIt disrupts Is ring of trachea- almost always avoided.Disadvantage: Perichondritis of cricoid cartilage, subglottic stenosisOnly indication: Carcinoma larynxMid tracheostomy:Done through 2nd or 3rd tracheal ringsPreferred approachLow tracheostomy:Below the level of isthmusDisadvantage: Trachea is close to major vessels at this level may get injuredTracheostomy tube may impinge on suprasternal notch 