Essentials of Anatomy and Physiology

of the eustachian tubes is to permit air to enter or

leave the middle ears, allowing the eardrums to vibrate

properly.

The nasopharynx is a passageway for air only, but

the remainder of the pharynx serves as both an air and

food passageway, although not for both at the same

time. The oropharynx is behind the mouth; its

mucosa is stratified squamous epithelium, continuous

with that of the oral cavity. On its lateral walls are the

palatine tonsils, also lymph nodules. Together with

The Respiratory System 345

Frontal sinus

Ethmoid bone Olfactory receptors

Conchae

Superior

Middle

Inferior

Nostril

Hard

palate

Maxilla

Palatine

bone

Sphenoid sinus

Opening of

eustachian tube

Pharyngeal tonsil

Nasopharynx

Soft palate

Uvula

Palatine tonsil

Oropharynx

Lingual tonsil

Epiglottis

Laryngopharynx

Esophagus

Hyoid bone

Larynx

Thyroid

cartilage

Cricoid

cartilage

Trachea

Figure 15–1. Midsagittal section of the head and neck showing the structures of the

upper respiratory tract.

QUESTION:Describe the shape of the conchae by using a familiar object. What is the func-

tion of the conchae?