Respiratory Basics – Answers

1) What is the primary function of the respiratory system?

The primary function of the lungs is to take in oxygen and give it to the blood, and to take carbon dioxide from the blood and get rid of it. In other words, the primary function of the lungs is gas exchange.


2) How many lobes do the lungs have? Why do you think that one side has fewer lobes than the other?

There are 5 lobes in the lungs: 2 on the left, and 3 on the right. The left lung only has only 2 lobes because there has to be enough room in the chest for the heart, and the heart sits mostly behind the left lung.


3) Besides providing a path for air, what are the 3 main functions of the nose? Or another way of phrasing the question: what are the benefits of breathing through your nose rather than breathing through your mouth?

The nose warms the air you breathe, humidifies the air, and filters out particles such as dust and bacteria. These three things all help to protect the lower airway from irritation and contamination. How do you think this could be applied when patients are on supplemental Oxygen?


4) Describe the pathway of air. Where does it enter the body? What structures does it pass through? Describe it in words or draw a picture and label it. Hint: It starts with your nose!

The Upper Respiratory Tract starts with air entering the nose, passing through the nasal turbinates, and into the pharynx. Then it goes past the epiglottis, larynx, and trachea. The trachea splits (another way of saying it is “bifurcates”) in two at the carina, and is now referred to as bronchi. The carina is where the Lower Respiratory Tract begins, and it is very ticklish! So if it gets touched, such as during suctioning, the patient will cough a lot!

The right and left bronchi are different sizes. The right bronchi is shorter, wider, and straighter than the left bronchi. So if the pt swallows something that “goes down the wrong pipe,” there is a good chance that it was aspirated into the right bronchi. So where do you think you are likely to auscultate (hear) adventitious (not normal) breath sounds in a pediatric patient who swallowed a coin?

The 2 main bronchi continue to divide into smaller and smaller bronchi. When they get small enough, we start calling them bronchioles. The bronchioles have the alveoli attached to them. The alveoli look like tiny bunches of balloons that can inflate and deflate as you breathe.


5) What is surfactant? Where do you find it? What is its function?

Surfactant is a substance that is found on the alveoli. It is a lipoprotein, which means that it will not mix with water because it is a lipid (fat). The function of the surfactant is to reduce surface tension of the alveoli, which makes them easier to inflate and deflate.


6) What would happen to the alveoli if there was not enough surfactant? In what kind of patient would you expect to see a lack of surfactant (hint: the answer to the second question is probably in your Maternity textbook)?

If there was not enough surfactant, then the alveoli would not be able to fill up with air. The air would get as far as the bronchi, then could go no further. You know those balloons that are used to make balloon animals? Have you ever tried to blow one up? It’s pretty hard to get it started! I can blow with all my might and only have a 50/50 shot at filling it with air. That’s what alveoli would be like without surfactant: you might be able to blow it up with air, but it’s a LOT harder.

Pre-mature babies (any baby born at < 37 weeks) often have not started producing enough surfactant at birth, which is why they frequently have respiratory problems. How is this condition treated in Preemies (hint: You might have to go back to your Maternity book for this one!)?


7) The first question in this study guide asked you what the primary function of the respiratory system is. In what part of the respiratory system does this primary function happen?

The alveoli are where the actual “gas exchange” takes place. If air can’t get into the alveoli, then the blood does not get any Oxygen. Where have you heard the phrase “Impaired Gas Exchange” in the past?


8) What is the difference between “Impaired Gas Exchange” and “Ineffective Airway Clearance?” Name a few reasons why air might not be able to get to the alveoli for Gas Exchange.

Impaired Gas Exchange occurs when the alveoli and capillaries can’t exchange oxygen and carbon dioxide normally. There are several reasons this could happen, but one of the most common is probably because of mucus or fluid in the lungs. The fluid sits in and around the alveoli, and so the air you breath in can’t get close enough to the capillaries to exchange oxygen and Carbon Dioxide. This nursing diagnosis could also be applied to patients who have Pulmonary embolism or decreased Cardiac Output. Both of those conditions would reduce the amount of blood flowing by the alveoli, which means less opportunity to exchange gases!

Ineffective Airway Clearance occurs when there is a partial or complete blockage somewhere in the respiratory tract. Again, the possible reasons are many! It could be that the patient swallowed a coin, which is blocking one of the bronchi (which side would it be more likely to block??). Or there could be mucus build up in the airway that the patient is having difficulty coughing up, or bronchial constriction related to Asthma.