3. Choose the correct word corresponding to the definitions below.

dense periosteum bone framework cavity spongy bone lamellae

1. It builds the rest of the body.

2. It forms the shafts of the long bones of the limbs.

3. It is found in the short bones and at the end of the long bones.

4. It contains yellow marrow.

5. It covers the outer surfaces of the short ones.

6. Circular plates.

4. Fill in the gaps.

1. Bone forms the ………….. .

2. Framework builds the rest of the body.

3. Bone is composed partly …………. , partly of ……… , mixed together.

4. Red marrow is engaged in the formation ………….. .

5. All bone is penetrated by a series of …………… .

6. Each lamella consists of ……………… .

7. Bones grow in …………………. sur­rounding them.

8. The long bones grow …………….. which runs across the bone at a short distance from each of its ends.

5. Expand sentences as in example. Example: Bone forms the framework. - Bone forms the framework , which builds the rest of the body.

1. The collection of the body is generally referred to as the "skeleton".

2. Bones grow in thickness.

3. Dense bone is found in a tube-like form.

4. The long bones grow in length.

5. Cancellous bone has a more open framework.

6. All bone is penetrated by a series of very fine canals.

6. Write five questions and ask other students. Skull

1. Read the new words to know:

skull - череп

irregularly shaped bones – кости беспорядочной формы

brain - мозг

mastication - жевание

nasal - назальный

pharyngeal passage – фарингальная полость

to pro­tect - защищать

socket – впадина, углубление

solid - твердый

to divide - разделять

face - лицо

flat - плоский

fibrous membrane – фиброзная оболочка

enclose - скрывать

cranium - череп

coarse - грубый

shape - форма

artificial - искусственный

carnivore – плотоядное животное

2. Read the vocabulary again and determine which words are of a lower level of generality, which of the same level, and which of the higher level for the theme “skull”.

Skull is the collection of flat and irregularly shaped bones, which pro­tects the brain and forms the skeleton of the face. These bones support the organs of mastication, keep patent the nasal and pharyngeal passages, hold the eye in its socket, give protection to the very delicate organs of hearing, and give the head of an animal its characteristic outline. The skull as a whole is not solid.

General Arrangement of the Skull. - The skull is divided into two parts: 1) the cranium, and 2) the face. The former consists of the posterior part, which encloses the brain, while the face lies entirely to the front of the head. In the young animal's skull these two portions can be separated, but in the adult the whole skull, except for the lower jaw is fused together into a complete whole. Most of the bones of the skull are flat bones developed from a structure, which is partly cartilage and partly fibrous membrane.

Bones of Cranium. - The bones, which enclose the brain and its mem­branes, are ten in number - four single and three paired.

The most striking feature of the skull of horse, ox, sheep, or pig is comparatively small size of the cranium compared to that of the face; but this is not so in the cat and the short-skulled breeds of dogs, such as the pug. or bulldog. In these latter the proportions more nearly resemble those of the human being. This is explained to some extent by the difference in size of the brain, but to a greater extent by the more extensive development of mouth and masticator organs. The more coarse and innutrition is the food the greater is the provision that must be made for chewing, and therefore the more extensive is the development of teeth, tongue, etc. In the carnivore the food needs less chewing, and the mouth and its contents are therefore smaller.

Another striking feature in ruminants is the comparative smallness and weak appearance of the incisive bones, occasioned by the absence of upper incisor teeth.

In dogs the shape of the skull and its proportions differ according to the breed. The skull has been altered by artificial selection over a long period of time probably more than any other part of the skeleton.

3. Give English equivalents of the following phrases: защищать мозг, поддерживать органы жевания, держать глаза в их впадинах, задняя часть черепа, частично хрящевой, частично из фиброзной оболочки, порода с коротким черепом, размер мозга;