How does nitroglycerin spray enter the body?

Nitroglycerin spray is classified as a sublingual medication, which means it is designed to be absorbed through the mucous membranes in the mouth, particularly under the tongue. When the spray is applied, the nitroglycerin is absorbed directly into the bloodstream from the tissues in the mouth. This method allows for rapid onset of action, making it effective in treating conditions like angina pectoris.

Inhalation would involve delivering medication through the respiratory system, which is not how nitroglycerin spray works. Ingestion refers to swallowing a medication, which would not be effective for nitroglycerin, as it would need to be metabolized through the gastrointestinal system before entering systemic circulation, delaying its action. Injection involves delivering a substance directly into the bloodstream through a needle, which is not applicable to the use of nitroglycerin spray. Therefore, absorption through the mucous membranes is the correct and appropriate route for nitroglycerin spray.