3. Fill in the table:

Function	Function describing

3. Retell the text round the circle. One student begins with the first sentence, the other continues and so on. Bone

1. Read following new words to know:

framework – костяк, скелет

skeleton - скелет

dense bone – плотная кость

shaft - кость

limb - конечность

spongy bone – решетчатая кость губчатого строения

tube-like form – трубчатой формы

central cavity – центральная каверна (впадина)

ribs - ребра

breast-bone - грудина

cartilage - хрящ

yellow marrow – желтый мозг

wall - стенка

periosteum. - прирост

cancellous bone – зубчатая кость

space - полость

red marrow – красный мозг

growth - рост

to cover - покрывать

lamel­lae - пластинка

plate of cartilage – пластинка хряща

2.Play “snow ball”. Use words of the given vocabulary, word rose and your own vocabulary. You say a word, and your neighbor repeats your word and says his own, next student repeats your word, your neighbors and says his own and so on.

Bone forms the framework upon which the rest of the body is built. The collection of the body is generally referred to as the "skeleton", but this term also includes the cartilages, which join the ribs to the breast-bone or sternum, form the larynx, etc. Structure of Bone. - Bone is composed partly of fibrous tissue, partly of bone-earth, mixed together. Two kinds of bone are considered: dense bone, such as forms the shafts of the long bones of the limbs, and cancellous or spongy bone, such as is found in the short bones and at the end of the long bones. Dense bone is found in a tube-like form, with a central cavity in which normally yellow marrow is found, composed mainly of fatty substances; the walls of the tube are stout and strong, and the outer surface is covered by "bone membrane" or periosteum. Cancellous bone has a more open framework, is irregular in shape, and, instead of possessing a cavity, its centre is divided into innumerable tiny spaces by a fine network of bony threads, which support the important red marrow. This red marrow is the tissue of the body that is engaged in the formation of red blood-cells. Periosteum also covers the outer surfaces of the short ones. All bone is penetrated by a series of very fine canals, in which run blood-vessels, nerves, lymph vessels, etc., for the growth, maintenance, and repair of the bone. Around these Haversian canals the bone is arranged in circular plates or scales which arc called lamel­lae, the lamellae are separated; from each other by spaces or "lacunae", each of which contains a single bone cell. Even the lamellae consist of fine tubes known as "canaliculi" carrying processes of the bone-cells. Each lamella consists of very fine interlacing fibres.

Growth of Bone. - Bones grow in thickness from the periosteum sur­rounding them, the inner surface of which is constantly transformed into hard bone; while the long bones grow in length from a plate of cartilage which runs across the bone at a short distance from each of its ends, and which on one sur­face is also constantly forming bone until the growth of the animal ceases.