Unit 22 and 23 Respiration System Quiz Questions

The condition pulmonary edema, in which fluid collects around alveoli, increases the thickness of the respiratory membrane. Predict the effect this would have on the efficiency of gas exchange. Explain your reasoning.

Efficient gas exchange depends upon the presence of an extremely thin respiratory membrane. Anything that increases the thickness of the respiratory membrane increases the distance that gases must diffuse, which makes gas exchange much less efficient.

Certain chest deformities prevent normal expansion of the chest. Explain why this makes ventilation difficult in terms of pressure and volume.

Expansion of the chest is required to increase the volume of the lungs and decrease their pressure below the level of atmospheric pressure. If the chest is unable to expand adequately, it will be very difficult for the inspiratory muscles to increase the lungs' volume enough to produce a deep breath.

Leda presents after an episode of food poisoning that caused prolonged vomiting. You notice during the exam that her respiratory rate is fairly low at eight breaths per minute. You run some lab tests and find that the pH of her blood is abnormally alkaline (basic), a condition called metabolic alkalosis. Are her respiratory rate and blood pH related? If so, how and why?

Her respiratory rate is low because her respiratory centers are attempting to compensate for the elevated pH of her blood. Hypoventilating will cause retention of carbon dioxide, which will decrease the pH of the blood, possibly back to the normal value.

The condition influenza is caused by a virus that infects the epithelium of the respiratory tract. The virus can cause severe inflammation of the airways, death of the epithelial cells, and excess secretion of mucus. Is influenza likely to show an obstructive disease pattern or a restrictive disease pattern? Predict the values you would expect to see on spirometry for a patient with influenza.

Influenza is an obstructive disease because airway inflammation and excess mucus obstruct airflow through the respiratory tract. One would expect to see a decreased ERV and VC and an increased RV and FRC with patients who have influenza.

When a patient has a procedure called a tracheostomy, a hole is cut into the trachea and a tube is inserted through which the patient breathes. This allows the air to bypass the upper respiratory tract and enter the trachea directly. Could this have potential negative consequences for the patient? Explain. (Hint: Consider the function of the nasal cavity and other upper airways.)

Normally much of the debris and pathogenic material that we inhale is filtered out in the nasal cavity by the turbulent air flow, the vibrissae, and the cilia-lined mucus membrane. When air bypasses the nasal cavity and other parts of the upper respiratory tract, it will have more debris and potential pathogens, increasing the potential for infection and obstructions.

The condition pulmonary fibrosis is caused by the replacement of elastic fibers in the lung with inelastic collagen fibers, which decreases the lungs' distensibility (the ability to stretch outward). Would pulmonary fibrosis make inspiration or expiration difficult? Explain.

Pulmonary fibrosis primarily affects inspiration, as the lungs are unable to stretch and sufficiently increase pulmonary volume.

A patient with influenza will have decreased pulmonary gas exchange occurring in the alveoli. What effect is this likely to have on the pH of a patient's blood? Explain.

The decreased pulmonary gas exchange will lead to a retention of carbon dioxide, which will lower the pH of the blood and cause respiratory acidosis.

You are working in an emergency department and have a patient who has stopped breathing. To ventilate the patient, you have inserted an endotracheal tube—a tube placed through the mouth and into the trachea. Your partner has begun ventilating the patient, when you notice that only the right side of the patient's chest is rising and falling with each breath. When you auscultate the patient's chest, you hear breath sounds in the right lung, but not the left lung. What has likely happened during the procedure? How can the mistake be fixed?

The endotracheal tube has likely gone down into the right primary bronchus. The mistake can be fixed by simply backing the tube out slightly so that it sits in the trachea instead of the right primary bronchus.

Certain viral or bacterial infections can cause inflammation of the epiglottis, a condition known as epiglottitis, which is considered a medical or surgical emergency. Why do you think epiglottitis is so dangerous?

The epiglottis is the superior part of the larynx that closes off the larynx during swallowing. When it is inflamed, it can block off the larynx when not swallowing, preventing a person from breathing.

Why does the ventilatory rate increase during exercise?

There are many reasons the ventilatory rate increases during exercise. One of the primary reasons is the production of more carbon dioxide. This decreases the pH of the blood, which triggers centers in the brain to increase the rate of ventilation to blow off the excess carbon dioxide and restore the blood pH.

A male patient presents with the following respiratory volumes and capacities: TV 4 500 mL, ERV 4 600 mL, IRV 4 2,700 mL. What is this patient's VC? Are these values normal? If not, are they more consistent with an obstructive or restrictive disease pattern? Explain.

This patient's VC is 3,800 mL, which is lower than normal for males. Tidal volume is normal but VC and ERV are much lower than normal, and IRV is slightly lower than normal. This is consistent with an obstructive disease pattern because the ERV is greatly diminished.

Explain how the epithelium in each of the following regions of the respiratory tract is adapted so its structure follows its function: Nasal cavity

pseudostratified ciliated columnar epithelium; cilia and goblet cells filter the inspired air and remove debris; the taller epithelium provides some protection from abrasion

Explain how the epithelium in each of the following regions of the respiratory tract is adapted so its structure follows its function: bronchiole

simple columnar to cuboidal epithelium with few goblet cells and no cilia; by the time the air reaches the bronchioles, the vast majority of dust and debris has been removed from the air, so few goblet cells (and no cilia) are needed to produce mucus. Also, the epithelium gets progressively shorter, reflecting the fact that the passage itself is getting progressively smaller.

Explain how the epithelium in each of the following regions of the respiratory tract is adapted so its structure follows its function: alveoli

simple squamous epithelium with no goblet cells, the squamous cells are very thin to facilitate diffusion of gases