With the basics of the EMS system and moving/lifting skills under our belt, we turn our attention to perhaps the two most critical elements of the EMT course: Human anatomy and development, and the overall plan of patient assessment necessary to determine appropriate treatment and transport priority.
EMTs are not doctors. We're not asked, expected, or required to diagnose what ails our patient. Heck, we're pretty much told to avoid jumping to any conclusions, and look to treat life-threats and transport safely to a higher-level medical care facility as our primary responsibility. While we may suspect kidney stones or gallstones, a broken toe, or an allergy to a specific food based on what a patient has told us they are experiencing by way of pain or discomfort, or what they were doing prior to the start of pain, at best we're told to maintain an "index of suspicion" rather than attempting to reach a conclusion and diagnoses. That's simply not the function of being an EMT.
As the primary function of the circulatory system is to move blood around the body in order to allow for exchange of Oxygen (O2) for Carbon Dioxide (CO2) at the cellular level through the capillaries that wind their way through and between the cells that compose all our organs, it's only natural to then speak to the respiratory system, which helps move O2 in to the body (and CO2 back out) via the structures of the nose, mouth, pharynx, trachea, bronchi, bronchioles, and lungs.
The differences between inspiration, the movement of air in to and out of the lungs, versus respiration, the exchange of O2 for CO2 within the alveoli of the lungs, and the relationship of these both to the circulation of O2 to the body cells and organs, is a critical understanding, These are the so-called ABC's -- Airway, Breathing, Circulation -- that every EMT will assess and attempt interventions to manage immediate life threats caused by a failure of the body to manage any or all of these elements.
Of course, making these systems (circulatory, respiratory, and even muscular elements like the diaphragm) work together requires a set of control structures. And coursework covers those as well, including the all important Central Nervous System (including the Brain and Spinal Cord), as well as the Autonomic Nervous System that keeps our bodies running without conscious effort. We also look at the endocrine system, and how certain chemicals our bodies manufacture, such as epinephrine (or adrenaline, as you might know it), can speed up (or slow down) how our systems operate.
Of course, the body needs fuel to run all this machinery, which leads us to the digestive system components, and then to the (closely related) urinary system. We continue on to learn how our largest organ, the integumentary system (which you probably know as the skin), also relates back to the nervous and circulatory systems. And we finally close with a quick study of the reproductive systems for both sexes.
Navigating the material, and understanding the cause-and-effect relationships these systems have on one another isn't necessarily easy, but it's not terribly difficult either. There's a lot of medical terminology to grasp, but I've found that when I can start to relate one topic or function to another, it become easier to manage.
Later in the course, I expect that we'll be coming around to each of these systems again (perhaps several times). After all, in order to recognize life threats and provide appropriate responses (or interventions, as they're referred to), it's important to understand what body systems are critical or may be impacted by any specific trauma or condition.
I just wish I had paid a bit more attention back in high school biology class.