Our chest is a large strong box made up of bones. The bones of chest form a cone-shaped cage which encloses the heart and lungs. The sides of chest cavity formed of twelve pairs of ribs. Our chest expands while we breathe in and contracts when we breathe out.

The front part lower jaws is called chin. The chin is important in the harmony of face and thus, helps in giving a good appearance.

Two sets of bones, upper and lower, forming the framework of mouth is called jaws. The human teeth are embedded in jaw bones. A human has 32 teeth; 16 each in the upper where the teeth are embedded in. an injury to the jaw endanger the existence of teeth. We should protect our jaws from hard blows. We should be very careful in protecting our jaws.

While playing the games of cricket and hockey etc. sometime, a ball moving with a fast speed hits the jaws. Injury to jaws may also occur while playing other fast games like basketball, boxing and kho-kho etc. in order to safeguard our jaws, we must be very careful while playing games.

Lungs and liver

We have two lungs. They are cone- shaped and occupy the whole cavity of thorax leaving a space for heart. The lower surface of the lungs is conclave in order to accommodate diaphragm. The left lung is smaller than the right lung.

Each lung is slate colored and partially divided into separate portions called lobes. The right lung is divided into three lobes and the left into two lobes. Both the lungs are enveloped in a membrane called pleura. The pleura are double layered. The space between the two layers is filled with s fluid. The lungs are surrounded by a boney case formed of bony ribs.

In order to create energy and to maintain the constant temperature of body, food containing fats and carbohydrates are burnt in the body tissues. This burning process requires the presence of oxygen. The lungs breathe in oxygen and breathe out carbon dioxide. Thus, the lungs play an important role in our life.

The liver is the largest gland of the body. It is dark brown gland and is situated in the upper part of the right side of the abdominal cavity. It weighs about one kilogram in human beings. Its lower border can be felt just under the lower-most rib.

The liver is the important organ of the body and is essential for human life. It performs many functions. One of the important functions of the liver is secretion of bile which is a brownish green fluid and is essential for the digestion of fats. It also destroys the harmful substances appearing in the bold stream. The excessive use of alcohol is very injurious to liver.

Nose and nails

Care of nose

The nose is one of the sense organs of our body. We smell things through our nose. We should always breathe in through our nose. Breathing in through our mouth may cause common cold and other chest diseases.

We should blow our nose every morning and clean it with water. We should never put our fingers, match-sticks and other foreign matters into our nostrils. We can use nasal drops in consultation with a doctor if our nostril het blocked.

Care of nails

Nails should be cut short. They should never be bitten by teeth because dirt that creeps under them may cause several ailments. Hands should be washed with soap and water in order to avoid all sort infections.

Care of hair

Cleanliness and care of the hair is also an important part of the personal hygiene. The ends of the hair penetrate into skin. If the hairs are not kept clean, various skin infections like ringworm, eczema etc. may crop up. Sometimes, growth of lice in the head may cause fever and irritation in the skin of the head. So, the hair should be kept clean and well groomed. Better course would be to keep the hair trim. In case of girls, the hair should be properly combed with the help of a brush.