The Skeleton

The skeleton is constructed of bones. A bone is any of the pieces of hard, whitish tissue making up the skeleton in humans.Bones are important in five ways. First, bones are the main support for the body; they give your body shape, the bones that make up your spine allow you to sit up straight, the bones in your legs support the weight of your body so that you can stand up and so on. Another function of your skeleton is movement. Muscles are attached to bones and when muscles move, bones move. Third, bones protect the organs beneath them. The ribs provide protection for the lungs and heart. The skull protects the brain. Fourth, yellow bone marrow stores calcium and fat. Finally, bones are the location where blood cells are produced by the cells of the red bone marrow. Bone marrow is located inside the marrow cavity of bones.

The skeleton can be divided into three basic parts: skull, axial skeleton, and appendicular skeleton. The bones of the skull consist of cranial and facial parts. There are 26 bones in the skull.

The axial skeleton is comprised of the bones that support the trunk. The bones of the trunk are the spinal column or the spine and the chest (ribs and the breastbone). The spine of the adult consists of 32 or 34 vertebrae. There are seven cervical vertebrae, twelve thoracic vertebrae, five lumbar, five sacral vertebrae and from one to five vertebrae which form the coccyx. The lumbar vertebrae are the largest vertebrae in the spinal column. The chest is composed of 12 thoracic vertebrae, the breastbone and 12 pairs of ribs.

The appendicular skeleton consists of the bones of the arms and legs, along with the bones that attach them to the axial skeleton.The lower extremity consists of the thigh, leg and foot. It is connected with the trunk by the pelvis. The upper extremity is formed by the arm, forearm and hand.

The bones of the skeleton are connected together by joints, cartilages, ligaments and tendons.

The biggest bone in the body is the femur in the upper leg, and the smallest is the stapes bone in the middle ear. In an adult, the skeleton comprises around 14% of the total body weight, and half of this weight is water.

The human skeleton takes 20 years before it is fully developed. There are 206 bones in the adult human skeleton, a number which varies between individuals and with age - newborn babies have over 270 bones some of which fuse together.

Exercise 7. Answer the questions:

1. What is the skeleton constructed of?

2. Why are bones important? What are their main functions?

3. What is the function of the skull?

4. Where is bone marrow located?

5. What parts can the skeleton be divided into?

6. How many bones are there in the skull of an adult?

7. What is the biggest bone in the body?

8. How many bones do newborn babies have? Why do adults have fewer bones?

Exercise 8. Find corresponding equivalents in the text:

Повністю розвинутий; складатися з кісток рук та ніг; прикріплені до кісток; зростатися; забезпечити захист; складати спинний хребет; накопичувати кальцій та жир; новонароджені діти; формувати куприк; потребувати 20 років; середнє вухо; варіюватися в залежності від віку; поділити на; черепна та лицьова частини; у дорослої людини; половина маси; зв’язки та сухожилля; розміщений у кістково-мозковій порожнині.

Exercise 9. Match the words with their definitions:

1. skeleton 2. vertebra 3. trunk 4. skull 5. femur 6. rib 7. spine 8. bone marrow

a) any of the 24 curved elastic bones that together form the chest wall in man b) the spinal column c) one of the bony segments of the spinal column d) the fatty network of connective tissue that fills the cavities of bones e) the longest thickest bone of the human skeleton, located between the pelvis and the below f) the bony skeleton of the head g) a hard framework consisting of bones that supports and protects the soft parts of a human body and provides attachment for muscles h) the body excluding the head, neck, and limbs