I
1. Lexics to the text.
• skeleton - скелет
• bone - кость
• cartilage - хрящ
• framework - остов
• by feeling - на ощюпь
• muscle - мышца
• spine and ribs - спинной хребет и ребра
• axis - ось
• vertebral - позвоночный столб
• vertebrae - позвонки
• chest - грудная клетка
• nerve cord - нервный ствол
• brain - мозг
• cushion - смягчать
• jointed - сочлененный
• breastbone - грудная кость, грудина
• joints - суставы
• gristly - хрящевой
2. 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.
II
1. Lexics to the text:
• skull - череп
• cavity - полость
• knob - выступ
• recesses - углубления, ямки
• shaking - покачивание
• sense - чувство
• smell - обоняние
• nasal region - носовая полость
• ears - уши
• jaw - челюсть
• biting and chewing - кусать и жевать
2. Read and translate the text:
Skull. The skull contains a large cavity in which the brain is situated and there is a large opening into the cavity which permits the nerve cord to enter and join the brain. At each side of this opening is a rounded knob which fits into corresponding recesses in the first vertebra making a movable joint. The movement at this joint is the movement of nodding the head. (Shaking the head is a movement which takes place at the joint between the first and second vertebrae.)
The skull is a complicated mass of bones joined together so as to allow no movement. Many of the bones unite with each other after childhood so that their separate outlines cannot be seen. When this joining up is complete the skull makes a strong protective cover for the brain. In babies the bones are still soft and on the top of the head, they do not form at all until the second year. This explains why it is important to prevent babies from banging their heads.
The skull also protects the sense or organs of smell in the nasal region and the delicate internal apparatus of the ears, and it provides a pair of bony recesses for the eyes. In addition, the upper jaw is immovably fixed to the skull, and the lower jaw is jointed to it, which permits biting and chewing.