Question

Centering for the AP projection of the upper airway is at the level of which of the following?

1) C3-4
2) C5-6
3) C7-T1
4) T1-2

Answer 1

The AP projection of the upper airway is centered at the level of C3-4, and the correct order of air passage during inhalation is from the pharynx → larynx → trachea → bronchi. The uppermost structure of the lower respiratory tract is the larynx.

Step-by-step explanation:

The correct centering for the Anteroposterior (AP) projection of the upper airway is at the level of C3-4. This region is typically the focus for AP upper airway radiographs to visualize the pharyngeal airway space and surrounding structures. The respiratory system begins with the airway at the pharynx, which bifurcates into two primary bronchi. These primary bronchi then branch into secondary bronchi, and subsequent tertiary bronchi lead to bronchioles and finally terminal bronchioles.

Inhaling air travels from the pharynx to the larynx, then through the trachea and finally into the bronchi, making the correct order B. pharynx → larynx → trachea → bronchi. The highest structure of the lower respiratory tract is the larynx, positioned below the pharynx and above the trachea.

If a patient has undergone surgical intubation, the intubation site is typically situated at the beginning of the pharynx. Any injury associated with this procedure is most likely to occur in these proximal areas of the airway.