| A | B |
|---|
| malleolus | The surface landmark of the ankle |
| mandible | The lower jaw bone |
| manubrium | Superior portion of the sternum |
| maxillae | The two fused bones that form the upper jaw |
| mechanism of injury (MOI) | The forces involved or factors influcening an injury |
| meconium | Dark green fetal waste material that passes into the amniotic fluid; if inhaled, it will cause fetal distress |
| medial | Toward the middle of a body or region |
| medical director | Physician experienced and knowledgeable in all aspects of emergency care who delegates emergency medical practice to non-physician providers, such as EMT-B and other EMS personnel |
| metacarpals | The hand bones |
| metatarsals | Foot bones |
| metered dose inhaler (MDI) | Hand-held inhalation device for delivering liquid or powdered medication in pre-measured doses |
| mid-axillary line | Imaginary line drawn vertically through the side of the body, extending from the middle of the armpit to the ankle, dividing the body into front and back sides |
| mid-clavicular line | Imaginary line drawn through the middle of the clavicle (or collar bone), dividing the body into unequal right and left sides |
| midline | An imaginary vertical line that divides the body into equal right and left sides |
| minimum data set | Patient and administrative information required to be included in a prehospital care report |
| miscarriage | Delivery of an embryo or fetus prior to viability; spontaneous abortion |
| mobile radio | Two-way radios that are usually built into emergency vehicles |
| multiple casualty incident (MCI) | Response that can involve a few serious injuries or several hundred patients; can place great demands on a local EMS system |
| musculoskeletal system | Consists of the muscular system and the skeletal system. A human body functions through the actions and interactions of these systems |
