Nasal Cavity & Paranasal Sinuses Review

A set of question-and-answer flashcards covering anatomy, vasculature, innervation, and clinical correlations of the nasal cavity and paranasal sinuses.

What are the two primary functions of the nasal cavity?

Inspiration of air (respiration) and olfaction (sense of smell).

Which portion of the nasal cavity is considered the respiratory zone and what fraction does it occupy?

The lower two-thirds; it conditions air by passing over the turbinates.

Where is the olfactory mucosa located within the nasal cavity?

In the upper one-third of the cavity, where olfactory bulbs project to detect smell.

What effect does taking a deeper breath have on smell perception?

It pushes more air toward the olfactory mucosa, enhancing the ability to smell.

Name the three structures that form the nasal septum.

Septal cartilage (anterior), perpendicular plate of the ethmoid bone (superior/posterior), and the vomer (inferior/posterior).

Which bones form the superior and middle nasal conchae?

They are parts of the ethmoid bone.

The superior and middle nasal conchae are parts of the ethmoid bone. Which of the three nasal conchae (superior, middle, or inferior) is unique because it is an independent bone, not part of the ethmoid?

The inferior nasal concha.

Why are the conchae also called turbinates?

Their curved surfaces create turbulence, increasing surface area to warm and moisten inspired air.

What clinical symptom results from the vascular, easily swollen mucosa covering the conchae?

Nasal congestion during colds or sinus infections.

Where is the sphenoethmoidal recess located and what sinus drains into it?

Between the superior concha and sphenoid bone; it receives drainage from the sphenoid sinus.

Define a nasal meatus.

The space on the lateral wall directly beneath a concha.

Which sinuses open into the superior nasal meatus?

The posterior ethmoidal air cells.

What are the three key features found in the middle nasal meatus?

Semilunar hiatus, ethmoidal infundibulum, and ethmoid bulla.

A patient is diagnosed with maxillary sinusitis. Anatomically, into which specific meatus and through which opening does the maxillary sinus commonly drain, and why is its upward drainage path clinically significant?

The maxillary sinus drains into the middle nasal meatus via the semilunar hiatus. Its drainage against gravity can make it prone to poor drainage and infection when inflamed.

Which structure leads to the frontal sinus through the frontonasal duct?

The ethmoidal infundibulum.

What does the ethmoid bulla represent and what drains there?

It represents the middle ethmoidal cells and drains 2–3 of those cells into the middle meatus.

What duct empties into the inferior nasal meatus?

The nasolacrimal duct (tears from the eyes).

The nasolacrimal duct.

An infant has persistent tearing and discharge from one eye, indicative of a blocked nasolacrimal duct. Into which specific nasal meatus does the nasolacrimal duct normally drain tears from the eye?

Which artery is the principal posterior blood supply to the nasal cavity and through which foramen does it enter?

The sphenopalatine artery via the sphenopalatine foramen.

A patient presents with recurrent nosebleeds originating from the anterior nasal septum. Given the high vascularity and convergence of several arteries, which clinically significant anastomotic area is the most likely source of bleeding?

Kiesselbach’s area.

Which branches of the ophthalmic artery supply the anterior portion of the nasal cavity?

The anterior and posterior ethmoidal arteries.

Which cranial nerve provides the majority of general sensory innervation to the nasal cavity?

The maxillary division (V2) of the trigeminal nerve.

Name the specific V2 branches that innervate the nasal cavity.

Nasopalatine, posterior superior nasal, and posterior inferior nasal branches.

Which nerve supplies the anterior part of the nasal cavity and from which division does it arise?

The anterior ethmoidal nerve from the ophthalmic division (V1) of the trigeminal nerve.

Following a traumatic head injury, a patient reports a complete loss of their sense of smell (anosmia). Which cranial nerve is primarily responsible for olfaction, and which specific region of the nasal cavity is essential for detecting odors?

The olfactory nerve (Cranial Nerve I) directly projects from the olfactory mucosa, located in the upper one-third of the nasal cavity, which is dedicated to detecting smell.