The mouth cavity Wordbuilding

-sub - префикс, указывающий на положение ниже чего-либо lingual - язычный sublingual - подъязычный

1.Guess the meanings and translate:

group - группа subgroup -

division - деление subdivision -

maxillary - челюстной submaxillary -

mandibular - нижнечелюстной submandibular -

cutaneous - кожный subcutaneous -

conscious - сознание subconscious -

normal -нормальный subnormal -

structure - структура substructure -

title - заголовок subtitle -

2. Try to remember these word combinations before reading the text:

to be subjected to - подвергаться

the prime organs - главные органы

alveolar ridges - альвеолярные отростки

insalivation - смачивание слюной

deglutition - глотание

to be invested - быть погруженным

to pour saliva - изливать слюну

to extend - простираться

dentition - ряд зубов

3. Look at the picture and show the accessory organs of the digestive system:

1 the gum

2 the tongue

3 the sublingual glands

4 the lips

5 the incisors

6 the canines

7 the premolars

8 the molars

9 the wisdom tooth

4. Read the text and be ready to answer some questions:

The mouth is an oval-shaped cavity situated at the beginning of the alimentary canal. In the mouth there are the teeth, tongue, and alveolar ridges, invested by the gum. The secretions of the parotid, submaxillary and sublingual glands are poured into the mouth cavity and in it the food is subjected to the processes of mastication and insalivation previous to deglutition. The teeth are the prime organs of mastication, and are implanted in the alveolar cavities.

A tooth is composed of four distinct structures:

1. The pulp occupying the chamber in the crown.

2. The dentine which constitutes the bulk of the organ.

3. The enamel which forms the protection of the crown.

4. The cementum which covers the root.

The teeth of the first dentition are termed deciduous or temporary teeth.

The temporary teeth are replaced by the permanent teeth. The anatomical divisions of a tooth are:

1. the crown or exposed part situated above the gum;

2. the root occupying the alveolar cavity of the socket;

3. the neck which is between the crown and the root.

The temporary teeth are twenty in number, ten in each jaw, namely: four incisors, two canines and four molars.

The permanent teeth are thirty two in number, sixteen to each jaw, namely: incisors - four, canines - two, premolars - four, molars - six. The third or last molar is called the wisdom tooth.

The incisors occupy the anterior central part of each maxillary arch. The function of this class of teeth is to cut the food.

The canine teeth are situated next to the incisors, two to each jaw. These teeth are for tearing the food.

The premolars, four to each jaw, are next to the canine teeth. They have two distinct cusps on their surfaces.

The molars occupy the posterior part of the alveolar arch and are six on each jaw. The function of the premolars and molars is to grind the food during mastication.

1. What sets of teeth do you know?

2. How many deciduous teeth are there on each jaw?

3. How many permanent teeth are there on each jaw?

4. Where is the mouth situated?

5. What classes of teeth are there?

EXERCISES

Ex. 1. Listen to the tape-recording of the text and prepare the fast reading of it.

Ex. 2. Give English equivalents:

овально-очерченная полость, секреция, жевание, ячейка, челюстная дуга, бугорок, разрезать пищу, первый ряд зубов, глотание, подвергаться, размалывать пищу.

1. The mouth cavity is situated ... the beginning ... the alimentary canal.

2. The tongue, teeth and the alveolar ridges are ... the mouth cavity.

3. The teeth are the prime organs ... mastication.

4. The enamel forms the covering and protection ... the crown.

5. The incisor teeth are used ... cutting the food.

6. The premolars have two distinct cusps ... their grinding surfaces.

Ex. 3 Give the correct forms of the verbs.

1. The patient (to examine) by the doctor tomorrow.

2. The teeth (to implant) in the jaw bones.

3. The roots of the upper wisdom tooth (to unite ) form one root.

4. We (to ask) by our professor to diagnose the case.

5. The food (to grind) during mastication by the teeth.

6. The secretion (to pour) by salivary glands.

Ex. .4 Translate the text without a dictionary:

The mouth is a part of the digestive system. There are the teeth, tongue, and salivary glands in the mouth. The cavity of the mouth is divided into two portions: the vestibule and the cavity proper. The vestibule of the mouth is a space bounded by the lips and cheeks. The lips and cheeks contain the mimic muscles. The oral cavity proper is bounded by the hard and soft palates. The hard palate separates the oral cavity from the nasal cavity. The mucous membrane covers the lips, and cheeks to the alveolar processes of the jaws. In the mouth the food is ground by the teeth and mixed with water, mucous and other secretions of the salivary glands. Saliva has the direct influence on the teeth and provides an optimal level of metabolic activity in the body. There are many salivary glands in the mouth; three principal pairs are recognized: the sublingual glands, submaxillary glands and parotids. The salivary glands regulate the water supply of the body.

Ex. 5. Answer the questions and check your answers:

1. What organs are there in the mouth cavity?

2. What does the mucous membrane cover?

3. What place do the molars (canines, incisors) occupy in the mouth cavity?

Lesson 8

DENTAL TISSUES