6. RIBS

Ribs are arched paired flat bones, connecting the spine and the breastbone, form the chest.

Ribs are curved, narrow plates, consisting of:

- bone (long spongy bones with head, neck and tubercle);

- cartilage.

The body of a rib has internal and external surfaces, limited with rounded and sharp edges. Vessels and nerves are situated in the sulcus, located in the internal surface of the lower edge.

There are twelve ribs on each side, and all articulate by their posterior ends with the bodies of the thoracic vertebrae. The anterior ends of the upper seven ribs are joined directly to the sternum by cartilages. These are the true ribs. The next three ribs, eighth, ninth, and tenth, are joined by their cartilages not to the sternum but to the cartilages of the rib next above, and are referred to as false ribs. The anterior ends of the eleventh and twelfth ribs lie free, and these ribs are called floating ribs.

The size and shape of the different ribs are closely associated with the shape of the thoracic cage and their location in relation to it. They increase in length from the first to the seventh rib. The seventh and the eighth ribs are the longest. The lower four ribs again diminish in length.

Functions of the ribs are:

- Protective. Ribs, forming the chest, protect the heart, the lungs and big vessels from injuries.

- Frame. The chest, which helps to preserve the organs in necessary position, prevents the heart from shifting and confusing with the lungs.

Table 6.1. Active Vocabulary

1. Ответьте на вопросы к тексту.

1. What are ribs?

2. What do ribs consist of?

3. What is the body of a rib limited with?

4. Where are nerves and vessels situated?

5. What are the true ribs?

6. What are the false ribs?