Respiration in Humen

The respiratory system of the human consists of the following structures: 1. Two outer nostrils. 2. Nasal cavity that is covered with a mucosal membrane and contains many glands that secrete mucus. 3. Two inner nostrils that open to the pharynx. 4. Pharynx, which is a common passageway for food and air. It contains a small piece of cartilage known as epiglottis. It prevents the entering of food molecules into the trachea. 5. Larynx, which contains vocal cords that help produce sounds. Hence, it is called a voice bOx.

It is a part of the respiratory system. It is a common passageway for food and air. It contains a small piece of cartilage known as epiglottis, which prevents the entering of food molecules into the trachea.

It is a part of the respiratory system. It contains vocal cords that help to produce sound.

It is a tube which is located in the chest in Oiont of the esophagus. The inner surface of the trachea is covered with mucous glands and cilia. 2. The nmucous glands of the trachea secrete mucus which moistens the air and the cilia catch and throw out foreign particles. 3. The trachea is divided into two branches called bronchi. The main bronchi are divided into smaller branches called bronchioles and they're located in the lungs. 4. In the lungs, bronchioles are subdivided into air sacs which consist of small rooms called alveoli. 5. Alveoli have thin walls surrounded by a network of blood capillaries which are branched from the pulmonary artery. 6. The exchange of gas between blood and the environment occurs through the walls of the alveoli.

In animals and humans, the lungs are located in the thorax, which is separated from the body cavity by a diaphragm.