Respiratory System
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NCLEX-PN › Respiratory System
What does the term "partial pressure" describe?
The pressure contributed by a single gas in a gas mixture
The pressure of a gas at 
The difference between the gas pressure at a particular altitude and sea level
The pressure of an overall gas mixture during transition (adding a new gas)
Explanation
Many gases, such as room air, are composed of several gasses (in the case of room air, primarily nitrogen, oxygen, and several trace gasses). Partial pressure is the amount of pressure that each gas contributes. To find the total pressure of a gas mixture, one would find the sum of all partial pressures of each individual gas.
What does the term "partial pressure" describe?
The pressure contributed by a single gas in a gas mixture
The pressure of a gas at
The difference between the gas pressure at a particular altitude and sea level
The pressure of an overall gas mixture during transition (adding a new gas)
Explanation
Many gases, such as room air, are composed of several gasses (in the case of room air, primarily nitrogen, oxygen, and several trace gasses). Partial pressure is the amount of pressure that each gas contributes. To find the total pressure of a gas mixture, one would find the sum of all partial pressures of each individual gas.
What structure is directly posterior to the trachea?
The esophagus
The cervical spine
The thyroid gland
The pharynx
Explanation
The esophagus is directly posterior to the trachea, and the cervical spine is posterior to the esophagus. The thyroid gland is anterior to the trachea. The pharynx is superior to both the trachea and the esophagus.
Which of the following is not a division of the pharynx?
The sinopharynx
The nasopharynx
The oropharynx
The laryngopharynx
Explanation
The pharynx is made up of three divisions: the laryngopharynx, the oropharynx, and the nasopharynx. There is no portion of the pharynx called the sinopharynx.
What structure is directly posterior to the trachea?
The esophagus
The cervical spine
The thyroid gland
The pharynx
Explanation
The esophagus is directly posterior to the trachea, and the cervical spine is posterior to the esophagus. The thyroid gland is anterior to the trachea. The pharynx is superior to both the trachea and the esophagus.
Which of the following is not a division of the pharynx?
The sinopharynx
The nasopharynx
The oropharynx
The laryngopharynx
Explanation
The pharynx is made up of three divisions: the laryngopharynx, the oropharynx, and the nasopharynx. There is no portion of the pharynx called the sinopharynx.
What structure of the lung is primarily responsible for controlling volume of air flow during respiration?
The bronchioles
The trachea
The bronchi
The alveoli
Explanation
The main mediator of air flow during respiration is the bronchiole. These tiny airways are wrapped in smooth muscle, which allows them to contract or relax in order to restrict or increase air flow in the lung. The trachea and bronchioles are cartilaginous rather than muscular, and are unable to constrict, while the wall of the alveolar sac is also devoid of smooth muscle, made up only of epithelial cells, capillaries, and connective tissue.
What structure of the lung is primarily responsible for controlling volume of air flow during respiration?
The bronchioles
The trachea
The bronchi
The alveoli
Explanation
The main mediator of air flow during respiration is the bronchiole. These tiny airways are wrapped in smooth muscle, which allows them to contract or relax in order to restrict or increase air flow in the lung. The trachea and bronchioles are cartilaginous rather than muscular, and are unable to constrict, while the wall of the alveolar sac is also devoid of smooth muscle, made up only of epithelial cells, capillaries, and connective tissue.
Which of the following pairs of sinus is absent at birth, and is not fully developed until puberty?
The frontal sinus
The ethmoid sinus
The maxillary sinus
The sphenoid sinus
Explanation
The frontal sinuses are not present at birth. They begin to develop in the first few years of life, but they are not fully mature until after adolescence. The sphenoid, maxillary, and ethmoid sinuses are present at birth, though they are underdeveloped and similarly do not mature fully till late childhood or adolescence.
Which of the following pairs of sinus is absent at birth, and is not fully developed until puberty?
The frontal sinus
The ethmoid sinus
The maxillary sinus
The sphenoid sinus
Explanation
The frontal sinuses are not present at birth. They begin to develop in the first few years of life, but they are not fully mature until after adolescence. The sphenoid, maxillary, and ethmoid sinuses are present at birth, though they are underdeveloped and similarly do not mature fully till late childhood or adolescence.