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I. Lexics to the text.
1. skeleton – ñêåëåò
2. bone – êîñòü
3. cartilage – õðÿù
4. framework – îñòîâ
5. by feeling – íà îùþïü
6. muscle – ìûøöà
7. spine and ribs – ñïèííîé õðåáåò è ðåáðà
8. axis – îñü
9. vertebral – ïîçâîíî÷íûé ñòîëá
10. vertebrae – ïîçâîíêè
11. chest – ãðóäíàÿ êëåòêà
12. nerve cord – íåðâíûé ñòâîë
13. brain – ìîçã
14. cushion – ñìÿã÷àòü
15. jointed – ñî÷ëåíåííûé
16. breastbone – ãðóäíàÿ êîñòü, ãðóäèíà
17. joints – ñóñòàâû
18. gristly – õðÿùåâîé
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II. Read and translate the text:
The General Plan of Our Skeleton. The skeleton is made up mostly of bone and a more flexible material called cartilage. it is a supporting framework of the body. It is not easy to find out where all the bones of your skeleton are by feeling, because many of them are well covered by flesh or muscle.
Spine and Ribs. The central axis of the skeleton is the spine, or vertebral column, which is not a stiff rod of bone. It is composed of a number of bones called vertebrae which move one against another and so twist and bend the whole column. There are 33 vertebrae in man and about 45 in a rabbit.
If you have a human skeleton, examine the vertebrae from the chest region of the spine. You will see that each has a large hole or spinal canal which, when the vertebrae are placed one above another, form a protective canal for the nerve cord which leads down from the brain. On the ventral side of this opening is the body of the vertebra, a large bobbin-shaped mass of bone. In the living state the bodies have discs of cartilage between their ends, which helps to cushion the brain from shocks when we jump. The three bony projections round the spinal canal serve as anchorages for the muscles which bend and straighten the spine. Each of the two lateral projections also has a rib jointed to it. There are usually 12 pairs of ribs in man and rabbit, and they help to form a protective cage for the heart and lungs inside. Their ventral ends are made of cartilage and join the breastbone which lies in the mid-line of the chest. The joints between the vertebrae and the ribs, and the gristly ends of the latter, make the chest cage flexible and it can be raised to increase its volume or lowered to decrease its volume, as happens during breathing.