Chapter 22, Problem 1TYR

The nasal cavity is divided by the nasal septum into right and left

a. nares.

b. vestibules.

c. fossae.

d. choanae.

e. conchae.

Summary Introduction

Introduction:

The respiratory system is an organ system that is involved in respiration or breathing. The nose serves as a source of entrance for air into the respiratory tract. The nose is a protruding structure found in the face. Its essential functions are detection of odors, breathing, and amplification of the voice. The nose is made of hyaline cartilage and bone. The anterior external openings of the nose are known as nostrils.

Explanation of Solution

Correct answer:

The nasal cavity is separated by the septum into right and left fossae. Therefore, option c is correct.

Justify reasons for the correct statement:

The internal chamber of the nose is known as nasal cavity which is divided into two halves, the left and the right nasal fossae.

Option (c) is given as, “fossae”.

Nasal fossae are a cavity inside the nostril that is separated by a vertical plate known as a nasal septum which is made of bone and hyaline cartilage.

Hence, option (c) is correct.

Justify reasons for the incorrect statements:

Option (a) is given as, “nares”.

Nares or nostrils are the external openings found on the anterior part of the nose. Hence, it is a wrong answer.

Option (b) is given as, “vestibules”.

The nasal vestibules lie anterior to the nasal cavity. It is a space inside the nares. So, it is a wrong answer.

Option (d) is given as, “choanae”.

The nasal choanae is a bony aperture that is formed by the bones superiorly by sphenoid, inferiorly by palatine, posteriorly by vomer, and medially by pterygoid plate of sphenoid. Hence, it is a wrong answer.

Option (e) is given as, “conchae”.

The nasal conchae are also called as turbinate. It is a narrow, elongated sea shell shaped bone that divides the nasal airway into four groove-like air passages. Therefore, it is a wrong answer.

Hence, options (a), (b), (d), and (e) are incorrect.

Conclusion

The nasal septum in the nostrils divides into the left and right nasal fossae.