Here are some diagrams and visuals to help you understand the structure of the respiratory system.

This diagram represents the organs and the structure of the respiratory system in a average person. As we can see, on the diagram labeled B, it is a close of the structure in the lungs, which is an important organ in the respiratory system. Diagram C, represents the how the oxygen and carbon dioxide is exchanged.

external image respiratory_system.jpg


Diagram Key points:

Lungs: The lungs are the important, vital, element of the respiratory system. The lungs are located on both sides of the heart, the left and right lung. The lungs function is to transport the oxygen inhaled into blood and to release carbon dioxide from the blood to the atmosphere.

Nasal cavity: What this part of the respirative system is does is warm, filter and moisten the incoming air from the nose
Pharynx: Here the throat divides into the trachea (wind pipe) and oesophagus (food pipe). There is also a small flap of cartilage called the epiglottis which prevents food from entering the trachea. Although not display in the diagram the Pharynx is located near the larynx a bit above it.

Larynx: This is also known as the voice box as it is where sound is generated. It also helps protect the trachea by producing a strong cough reflex if any solid objects pass the epiglottis.

Trachea: Also known as the windpipe this is the tube which carries air from the throat into the lungs. It ranges from 20-25mm in diameter and 10-16cm in length. The inner membrane of the trachea is covered in tiny hairs called cilia, which catch particles of dust which we can then remove through coughing. The trachea is surrounded by 15-20 C-shaped rings of cartilage at the front and side which help protect the trachea and keep it open. They are not complete circles due to the position of the oesophagus immediately behind the trachea and the need for the trachea to partially collapse to allow the expansion of the oesophagus when swallowing large pieces of food.

Bronchi: The trachea divides into two tubes called bronchi, one entering the left and one entering the right lung. The left bronchi is narrower, longer and more horizontal than the right. Irregular rings of cartilage surround the bronchi, whose walls also consist of smooth muscle. Once inside the lung the bronchi split several ways, forming tertiary bronchi.

Bronchioles: Tertiary bronchi continue to divide and become bronchioles, very narrow tubes, less than 1 millimeter in diameter. There is no cartilage within the bronchioles and they lead to alveolar sacs.

Alveoli: Individual hollow cavities contained within alveolar sacs (or ducts). Alveoli have very thin walls which permit the exchange of gases Oxygen and Carbon Dioxide. They are surrounded by a network of capillaries, into which the inspired gases pass. There are approximately 3 million alveoli within an average adult lung.

Diaphragm: The diaphragm is a broad band of muscle which sits underneath the lungs, attaching to the lower ribs, sternum and lumbar spine and forming the base of the thoracic cavity

Capillary: The Capillary is the smallest and the thinnest blood veins in the body. the capillaries surround and cover the Alveoli,so that they can easily collect oxygen from the alveolies and transport them throughout the whole body through the blood stream.

"Human Respiratory System." teach pe. N.p., n.d. Web. 16 Feb. 2012.

For further knowledge about the respiratory system, this is a video explaining the process of respiring and ventilating.

Works Cited
Dannishi. Respiration-Ventilation 3D Medical Animation. Youtube. N.p., 25 Sept. 2008. Web. 14 Feb. 2012. <‌watch?v=HiT621PrrO0>.

Darling, David. Respiratory system. N.d. The Encyclopedia of Science. N.p., n.d. Web. 14 Feb. 2012. [[‌encyclopedia/‌R/‌ respiratory_system.html]].

"Human Respiratory System." Web. 21 Feb. 2012.

Oak, Manali. “Structure of the Human Respiratory System.” Buzzle. N.p., 2012. Web. 4 Mar. 2012. <>.