Vestibule is located behind the nares and is continuous with the skin.

Epithelium is composed of stratified squamous cells that are similar to the contiguous skin.

Hairs and glands that extend into the underlying connective tissue constitute the first barrier to foreign particles entering the respiratory tract.

Posteriorly, the vestibular epithelium becomes pseudostratified, ciliated, and columnar with goblet cells (respiratory epithelium).

Respiratory area is the major portion of the nasal cavity.

Mucosa is composed of a pseudostratified, ciliated, columnar epithelium with numerous goblet cells and a subjacent fibrous lamina propria that contains mixed mucous and serous glands.

Mucus produced by the goblet cells and the glands is carried toward the pharynx by ciliary motion.

The lateral wall of each nasal cavity contains three bony pro jections, the conchae, which increase the surface area and pro mote warming of the inspired air. This region is richly vascularized and innervated.

Olfactory area is located superiorly and posteriorly in each of the nasal cavities.

The pseudostratified epithelium is composed of bipolar neu rons (olfactory cells), supporting cells, brush cells, and basalcells. The receptor portions of the bipolar neurons are modi fied dendrites with long, nonmotile cilia.

Under the epithelium, Bowman's glands produce serous fluid, which dissolves odorous substances.

Paranasal sinuses are cavities in the frontal, maxillary, ethmoid and sphenoid bones' that communicate with the nasal cavities.

The respiratory epithelium is similar to that of the nasal cavi ties except that it is thinner.

Numerous goblet cells produce mucus, which drains to the nasal passages. Few glands are found in the thin lamina propria.

New words

respiratory system – дыхательный аппарат

exchange – обмен

oxygen – кислород

carbon – углерод

dioxide – диоксид

cellular – клеточный

membrane – мембрана

deep – глубоко

capillary – капилляр

conduct ing – проведение

portion – часть

nasal cavity – носовая впадина

pharynx – зев

larynx – гортань

trachea – трахея

bronchi – бронхи

bronchioles – бронхиолы

inspiration – вдохновение

expiration – истечение

the paired – соединенный

nasal septum – носовая перегородка

anteriorly – раньше

nostril – ноздря

posteriorly – сзади

vestibule – вестибулярный

respiratory area – дыхательная область

olfactory area – обонятельная область

paranasal sinuses – параназальные пазухи

somebody – кто-нибудь, кто-то

Употребление somebody, anybody, nobody или everybody.

1. Утвердительная форма:

Не asked somebody to help him.

2. Отрицательная форма:

He asked nobody to help him. He did not ask any body to help him.

3. Вопросительная форма:

Did he ask anybody to help him?

Вставьте somebody, anybody, nobody или everybody.

1. Has… in this group got a dictionary?

2… left a magazine in our classroom yesterday.

3. The question was so difficult that… could answer it.

4. I am afraid I shan't be able to find… in the office now: it is too late.

5… knows that water is necessary for life.

6. Is there… here who knows French?

7. You must find… who can help you.