How is a substance introduced directly into the body?

A substance is introduced directly into the body through injection, which involves administering the substance via a syringe or needle. This method allows for the rapid delivery of medications or fluids directly into the bloodstream or specific tissues, bypassing the digestive system or respiratory pathways altogether. This is particularly valuable in emergency medical situations, where quick therapeutic effects are needed or when a patient is unable to take medications orally.

Injections can be subcutaneous, intramuscular, or intravenous, each serving different purposes and levels of urgency in treatment. Understanding the method of administration is crucial in EMT practice, as it influences the onset and efficacy of the medication or substance being delivered, ensuring the most appropriate and effective care for patients.