ANATOMICAL STRUCTURE OF A TOOTH

Exercise 3.1. Study the active vocabulary for the lesson:

specialized – специализированный

calcified – окаменелый

attach – прикреплять

incise – надрезать

maxilla – верхняя челюсть

maxillary – верхнечелюстной

mandible – нижняя челюсть

masticate – жевать

assist – принимать участие

alveolus (pl -li) – альвеола

alveolar – альвеолярный

cement – цемент

crown –коронка

root – корень

incisor – резец

dentine – дентин

dental pulp – пульпа зуба

enamel – эмаль

root canal – корневой канал

fibrous – волокнистый

chew – жевать

lamina dura – тонкая твердая пластинка

line – выстилать

occupy – занимать

periodontal membrane – корневая оболочка, периодонт

serve – служить

tooth socket – ячейка зуба

vascular – сосудистый

Exercise 3.2. Read the text and translate it into Russian:

Text A. Anatomical Structure of the Tooth

The teeth are specialized, hard, calcified organs attached to the maxilla and mandible. The function of the teeth is to incise, masticate food and assist in phonation.

Anatomically, a tooth consists of two fundamental parts: the crown and the root, or roots. The crown of the tooth appears above the gum line; it is only about 1/3 of the whole tooth. Underneath the gum line the roots lie. The root is in the alveolar bone and is covered by mucous membrane.

Incisors have only one root; other teeth, two or three roots. The crown and the root of the tooth are connected together by the neck.

The crown of each tooth is covered with dental enamel which is the hardest substance in the body. The roots are encased in cement (or cementum).

Inside the enamel and cement there is a softer bony substance called dentin. The dentin surrounds a pulp chamber (dental pulp), where nerves and blood vessels of the tooth are located.

The nerves and blood vessels run up and down through narrow channels, called root canals.

The periodontal membrane or alveolar-dental periosteum is a fibrous membrane. Covering the roots of the tooth it holds the tooth in its socket in the jaw and takes up some of the shock of chewing.

This is why the teeth are slightly movable. The periodontal membrane serves to attach the tooth to the bone.

A thin layer of bone called the lamina dura serves to line the alveolus or tooth socket.

Exercise 3.3. Complete the sentences, using the words from text A:

1) …. is visible part of a tooth, above the gums. 2) The …. is the hardest substance in the body. 3) ….. is the part of a tooth under the gums and inside the alveolar bone. 4) ….. is the area between the tooth crown and the root. 5) A tooth consists of three parts – the …., the …. and the …. . 6) The crown of each tooth is covered with ….. . 7) The ….. and …. run up and down through narrow channels. 8) The ….. is a fibrous membrane.

Exercise 3.4. Translate the words having the same root:

- to specialize, specialization, specially, specialty, specialist

- to calcify, calcification, calcium

- life, to live, living

- a nerve, nervous

- a group, to group

- to assist, assistant, assistance

- to cover, covered, covering

- to connect, connected, connective, connection

- membrane, membranous

- fiber, fibrous

- alveolus, alveoli, alveolar.

Exercise 3.6. Study the active vocabulary for text B:

devoted – посвященный

human tooth – зуб человека

embryonic – эмбриональный

cell – клетка

form – формировать

grow – расти, вырастать

erupt – прорезываться

tiny pieces – крошечные кусочки

layer – слой

incisor – резец

canines – клык

cuspid – клык

premolar – ремоляр, малый коренной зуб

bicuspid – премоляр, малый коренной зуб

molar – моляр; коренной

pointed – заостренный

chisel-shaped – остроконечный

cone-shaped – конусообразный

flat – плоский, ровный

apical – апикальный, верхушечный

rip – рвать, разрывать

peaks – вершины

valleys – впадины

grind – молоть, растирать

Exercise 3.7. Read text B and translate it into Russian: