Respiratory system

CONTENTS
* Introduction
* The Respiratory System
* Anatomy and Physiology
* The Heart and Lungs
* The Physiology of Breathing
* The Upper Respiratory Tract
* The Nasal Cavity and Sinuses
* The Ear
* The Lower Respiratory Tract
* The Lobes of the Lungs
* The Trachea, Bronchial Tubes and Aveoli
*Cilia
* When Something Goes Wrong
* Allergies
* Asthma
* Emphysema
* Sinus Trouble
* Otitis Media (Middle Ear Infections)
* Lifestyle Suggestions
* Conclusion
* Bibliography

Introduction

The respiratory system enables us to produce energy by supplying the body with a continuous supply of oxygen. It is also responsible for eliminatingcarbon dioxide, a by-product of cell metabolism. Whereas oxygen is necessary for human and animal respiration, carbon dioxide is necessary for plant respiration. Plants take in carbon dioxide and release oxygen, their waste product, and the cycle of interdependence between plants and animals continues.

The Respiratory System
The Respiration is the process by which living organisms take inoxygen and release carbon dioxide.
* Anatomy and Physiology
* The heart and lungs
The four-chambered human heart is divided into two separate pumps, the "right heart" and the "left heart." The right heart (consisting of the right atrium and ventricle) collects deoxygenated blood returning from the body by way of the veins and pumps it through the lungs where carbon dioxide is eliminatedand fresh oxygen is picked up. From the lungs, the newly oxygenated blood is collected by the left heart (the left atrium and ventricle) and is pumped, by way of the aorta, throughout the body to supply the cells with oxygen and to collect carbon dioxide for elimination the next time through.

* The Physiology of Breathing
The act of breathing is performed primarily by the diaphragm, alarge muscle that separates the thoracic cavity from the abdominal cavity. During the inspiration (breathing in), the diaphragm contracts for to create a vacuum in the thoracic cavity. This vacuum inflates the lungs by drawing air into the body through the trachea, or windpipe. During normal expiration (breathing out), the diaphragm relaxes allowing the air to flow out as the lungs deflate, similar tothe way an inflated balloon deflates when released.

The Upper Respiratory Tract
* The Nasal Cavity and Sinuses
Proper breathing involves drawing air in through the nose. The nasal cavity warms and moistens the air and filters it of impurities. Tiny hairs and sticky mucous membranes trap foreign materials before they can enter the delicate tissues of the lungs. Structures in the nasalcavity called concha. The function of the concha is increase the surface area allowing maximum efficiency.
The sinuses are hollow areas, or cavities, in the bones of the skull that are lined with mucous membranes and that open into the nasal cavity. The sinuses provide resonance for the voice. When the sinuses are inflamed and filled with mucus the voice has a different quality, often referred to as"nasal" in character.
* The ear
Because the middle ear chamber drains into the upper respiratory tract, by way of the eustachian tube, the middle ear is often considered part of the respiratory system.
When the eustachian tube becomes blocked, fluid can build up in the middle ear chamber. Bacteria can take advantage of the situation and proliferate, resulting in inflammation and infectionin the middle ear. Such a condition is referred to as otitis media [ot-, ear + itis, inflammation] or simply, a middle ear infection.
The Lower Respiratory Tract
Moving further down the respiratory tract we reach the larynx, or "voice box," which contains the vocal cords. The voice is produced by controlled vibrations of the vocal cords as air is pushed out of the lungs and through the...