6.
I.
II. 4 5.
III. . -1, -2
1. :
specialized [ˈspɛʃ(ə)lʌɪzd] adj,
calcified [ˈkælsɪfaɪd] adj,
attach [əˈtatʃ] v,
incise [ɪnˈsʌɪz] v,
maxilla [makˈsɪlə] n,
maxillary [makˈsɪləri] adj,
mandible [ˈmandɪb(ə)l] n,
masticate [ˈmastɪkeɪt] v,
assist v,
alveolus [ˌalvɪˈəʊləs] (pl -li) n,
alveolar [alˈvɪələ] adj,
cement [sɪˈmɛnt] n,
crown n,
root n,
incisor [ɪnˈsʌɪzə] n,
dentine [ˈdɛntiːn] n,
dental pulp [pʌlp]
enamel [ɪˈnam(ə)l] n,
root canal
fibrous [ˈfʌɪbrəs] adj,
chew [tʃuː] v,
lamina dura [ˈlamɪnə ˈdjʊərə]
line v,
occupy v,
periodontal membrane ,
serve v,
tooth socket
vascular [ˈvaskjʊlə] adj,
2. A.
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 lie the roots. The root is in the alveolar bone and is covered by mucous membrane.
Incisors have only one root; other teeth, two or three. 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 is the 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. Cover 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.
3. Complete the sentences, using the words from the text:
1) ______ is a 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.
