Body cavity which is opened first on post moem examination

Routinely thorax is the first cavity most commonly opened on PM examination. In aspyxial deaths, dissection of the head is recommended prior to body because a bloodless field . In case of poisoning: After the opening of the skull we may immediately smell the presence of volatile, poisonous substances (e.g., ethanol, cyanide, solvents, etc.) without competing odours from thoracic and abdominal cavity