Ex. 26. Read the following words and try to memorize them:

Epiphysis [e'pIfIsIs] епіфіз; epiphyseal line [epI'fIzIql] епіфізарна лінія; cartilage ['ka:tIlIG] хрящ; compact bone ['kOmpxkt 'boun] компактна кісткова тканина; cancellous bone ['kxnsqlqs] сітчаста кістка, губчаста кісткова речовина; spongy bone ['spAnGI] губчаста кісткова речовина; matrix ['meItrIks] матрикс, основа, міжклітинний матеріал; сavity ['kxvItI] порожнина; rigid ['rIGId] жорсткий, негнучкий, твердий; medullary [me'dAlqrI] медулярний, мозковий; серцевинний; maintain [meIn'teIn] підтримувати, утримувати, зберігати; support [sq'pO:t] підтримка; sinus ['saInqs] пазуха; fill with [fIl] наповнювати(ся); band [bxnd] зв'язка; approximately [q'prOksImItlI] близько, приблизно; marrow ['mxrqu] кістковий мозок; broad [brO:d] широкий; periosteum ["perI'OstIqm] окістя, надкісниця; fit [fIt] підходити, відповідати; dense [dens] щільний, густий; diaphysis [daI'xfIsIs] діафіз, середня частина трубчастої кістки.

Ex. 27. Read the following text:

Bone's structure

The skeletal system consists of bones, cartilages, tendons, and ligaments. Because bone is very rigid, it is well adapted to help maintain the shape of the body and protect internal organs. Cartilages, which are somewhat rigid but more flexible than bones, also provide support. Tendons and ligaments are strong bands of fibrous connective tissue. Tendons attach muscles to the bones, and ligaments attach bones to bones.

Individual bones can be classified according to their shape as long, short, flat, or irregular. Most of the bones of the upper and lower limbs are long bones. These bones are very strong. They are broad at the ends where they join with other bones, and have large surface areas for muscle attachment. Short bones are approximately as broad as they long. They are nearly cube shaped or round. They are in the wrist and ankle. Flat bones have a relatively thin, flattened shape. The examples of flat bones are some skull bones, ribs, pelvic bones, and the breastbone (sternum). Irregular bones are ones such as the vertebrae and facial bones with shapes that do not fit into three categories.

Each long bone consists of three major components: the diaphysis; an epiphysis; and the epiphyseal line (or epiphyseal plate in each growing long bone). The diaphysis is long middle region of a long bone composed of compact bone, which is bone matrix. Each end of a long bone is called an epiphysis. The epiphyses consisting of cancellous bone (sometimes called spongy bone), has many small spaces or cavities within the bone matrix. The outer surface of the epiphyses consists of a layer of compact bone. In addition to the small spaces within cancellous bone and compact bone, some bones contain large cavities. The diaphyses of long bones have a large medullary cavity (some of the skull bones have spaces called sinuses). The medullary cavity and the cavities of the cancellous bone are filled with marrow. Medullary cavity contains yellow bone marrow and spaces in cancellous bone contain red bone marrow. Yellow bone marrow is mostly composed of adipose tissue. Red bone marrow is the site of blood formation. In general, yellow marrow is associated with the long bones of the limbs, and red marrow is associated with the rest of the skeleton. The outer surface of bones consists of a periosteum. The periosteum is a strong, fibrous, vascular membrane that covers the surface of a long bone, except at the ends of the epiphyses. The inner layer consists mostly of a single layer of osteoblasts with a few osteoclasts. Osteoblasts are bone producing cells, and osteoclasts are cells breaking down bone.

Flat bones usually have no diaphyses or epiphyses. They contain an interior framework of cancellous bone sandwiched between two layers of compact bone. Short and irregular bones have a composition similar to the epiphyses of long bones. They have compact bone surfaces surrounding a cancellous bone center with small spaces that usually filled with marrow. Short and irregular bones have no diaphyses. However, certain regions of these bones (e.g., the processes of irregular bones) have epiphyseal growth plates and therefore have small epiphyses.

Ex. 28. Answer the following questions:

1. What does the skeletal system consist of? 2. What is the major function of the bone? 3. What does the cartilage provide? 4. What are ligaments and tendons? 5. What are their functions? 6. What types of bones do you know? 7. What components does every long bone consist of? 8. What is diaphysis composed of? 9. What does the epiphysis consist of? 10. What is compact bone? 11. What is osteoblast? 12. What is osteoclast? 13. What do the flat bones contain? 14. What are short and irregular bones composed of?

Structure of Bone

Ex. 29. Match the following terms with their definitions:

1. Cartilage	1. noncellular substance surrounding the cells of connective tissue.
2. Ligament	2. dense plate of bone in a bone that is no longer growing, indicating the former site of the epiphyseal plate.
3. Tendon	3. similar molecules binding to the same carrier molecule or receptor site.
4. Compact bone	4. band of dense connective tissue connecting a muscle to a bone or other structure.
5. Epiphyseal line	5. portion of a bone developed from a secondary ossification center and separated from the remainder of the bone by the epiphyseal plate.
6. Epiphysis	6. band of dense connective tissue connecting two or more bones, cartilages, or other structures.
7. Matrix	7. firm, smooth, nonvascular connective tissue.