EMT-Basic Exam: The Basics of Airway - Parts of the Respiratory System

Airway
The airway section of the EMT-Basic exam tests your knowledge of the different parts and functions of the respiratory system. You’ll also be tested on what to do when the airway is obstructed (blocked) and on your knowledge of different artificial ventilation techniques.
About 18 percent of the NREMT cognitive exam tests your knowledge of the respiratory system using fact-based and scenario-based questions. The fact-based questions are designed to test your comprehension skills, while the scenario-based questions present a situation and ask you what needs to be done next. These types of questions assess your ability to apply what you’ve learned to real-life situations.
The information and practice questions in this section should be used to review what you’ve already learned about the respiratory system.
 

The respiratory system is made up of the parts of the body in which air passes through, including the mouth, nose, lungs, pharynx, trachea, and bronchi. Collectively, these passageways are known as the airway. The main function of the respiratory system is to take oxygen into the lungs by way of either the nose or the mouth and then release carbon dioxide back out through the nose or the mouth. An obstructed (blocked) airway is an extremely dangerous situation that can result in death if left untreated. As an EMT-Basic, one of your most important jobs is to ensure that the patient’s airway remains open and clear at all times.

1. Parts of the Respiratory System
You are probably already familiar with the different parts of the respiratory system. In this section, you’ll find an overview of the function of the organs in the respiratory system.
When you breathe in air through your mouth or nose, air travels to the pharynx (throat), which is located directly behind your mouth and nasal cavity. The pharynx connects the nasal and oral cavities to the larynx, or voice box. The pharynx is divided into two parts: the nasopharynx, which is located behind the nasal cavity, and the oropharynx (back of the throat), which is located below the nasopharynx.
Air flows from the pharynx to the trachea, or windpipe, through the glottis, the middle of the larynx that houses the vocal cords. A flaplike structure above the glottis called the epiglottis prevents food or liquid from entering the trachea. The air continues through the trachea and passes the cricoid ring, which is the first tracheal ring. EMT-Basics should be familiar with the location of the cricoid ring because it is the only complete ring of cartilage in the trachea.
After that, air continues to flow into the right and left bronchi, the large tubes that connect the trachea to the lungs. The air passes through the bronchi and eventually reaches the alveoli, which are tiny air sacs where oxygen and carbon dioxide are exchanged.
Two muscle groups aid in respiration: the diaphragm and the intercostal muscles. The diaphragm is a large muscle that extends across the bottom of the rib cage. The intercostal muscles are located between the ribs and help move the chest cavity outward during inhalation and inward during exhalation. During inhalation, the diaphragm and the intercostal muscles contract to increase the size of the chest cavity. The diaphragm moves downward as the ribs move outward to allow air to flow into the lungs. During exhalation, the diaphragm and the intercostal muscles relax to decrease the size of the chest cavity. The diaphragm moves upward and the ribs move inward to push air out of the lungs.

A view of the respiratory system.

2. Adequate Breathing
Two types of breathing rhythms exist: adequate and inadequate. Adequate, or normal, breathing occurs when a person breathes at an adequate, or normal, depth and rate to meet the oxygen demands of the body. The number of breaths a person takes per minute is called the respiratory rate. The following are normal respiratory rates:
- Adults: 12–20 breaths per minute
- Children: 15–30 breaths per minute
- Infants: 25–50 breaths per minute
The amount of air a person inhales and exhales in a single breath varies. The air breathed in and out is called the tidal volume. The normal tidal volume for an average adult is 500 ml.
Adequate breathing is relaxed and quiet. A person who exhibits an adequate breathing rhythm produces equal breath sounds, exerts minimal effort when breathing, and expands the chest equally.

3. Inadequate Breathing
Inadequate, or irregular, breathing is defined as stressed or labored. A person who exhibits an inadequate breathing rhythm produces no breath sounds, exerts effort when breathing, and may expand the chest unequally.

Tip: All inadequate breathing cases are emergency situations.

As an EMT-Basic, one of the most important skills you’ll learn is to recognize the signs of inadequate breathing patterns. A person who is having difficulty breathing may exhibit one or more of the following signs:
- Shortness of breath
- Too fast or too slow respiratory rates
- Irregular rhythm
- Nonexistent breath sounds
- Shallow, unequal chest expansion
- Pale, cyanotic (blue), or clammy skin
- Retractions above clavicles or between ribs
- Nasal flaring or seesaw breathing in children or infants
- Gasping breaths
- Changes in consciousness

Related Topics You Should Review:
- Respiratory anatomy: location of the different parts of the respiratory system
- Respiratory physiology: the process of exchanging oxygen and carbon dioxide
- Functions of the alveolar sac and capillaries during gas exchange
- Differences in airway structure for adults, children, and infants, such as tongue, trachea, and chest wall size, and cricoids ring development
- Hypoxia: condition in which the body’s tissues and cells don’t get adequate oxygen