Respiratory System

Functions:

• Provides for gas exchange: takes in oxygen for the cardiovascular system to distribute to cells, and removes carbon dioxide produced by cells.
• Helps regulate the pH of our blood.
• Contains receptors for smell, filters, warms and moistens inspired (incoming) air, produces sounds, and excretes some water and heat.

Parts of the Respiratory System: The organs of the respiratory system can be classified via their location within the body or via their respective functions.

Division by Location:

1. Upper Respiratory System: Nose & Pharynx.
2. Lower Respiratory System: Everything else!

Division by Function:

1. Conduction Portion: the interconnecting cavities and tubes that conduct (bring) air into the lungs. This includes the nose, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.
2. Respiratory Portion: the places where gas exchange actually happens within the lungs. This includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

Some Special Terminology:

• otorhinolaryngology: the branch of medicine that deals with the diagnosis and treatment of the ear, nose, and throat.
• pulmonology: study of the lungs.
• pulmonologist: specialist in the field of diagnosis and treatment of lung diseases.
• respiration: process of gas exchange within the body.
• mediastinum- the space, within the thoracic cavity, in which the heart rests.

Respiration During respiration, four (4) distinct processes must happen.

1. Pulmonary Ventilation=breathing.
2. External Respiration-gas exchange between the air and alveoli.
3. Transport-carrying gases to/from cells and tissues.
4. Internal Respiration-gas exchange between blood and cells.

Controlling the Respiratory System

Normal breathing is controlled by two structures in the brain:

1. Medulla oblongata-sets the rhythm of breathing.
2. Pons-adjusts the length of inspirations.

Changes in normal breathing patterns are contributed to by:

1. Limbic System
2. Hypothalamus\

People breathe involuntarily, we don't have to think about it to do it! Some marine animal breathe voluntarily, such as cetaceans (whales, dolphins), and can only allow half of their brain to sleep at one time.

You cannot force yourself to quit breathing. Even if you hold your breath until you pass out, buildup of the carbon dioxide molecule and hydrogen ions stimulates your body to breathe again.

Links!

Respiratory Anatomy:

• http://sprojects.mmi.mcgill.ca/resp/anatomy.swf
• http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=40743

Gas Exchange Animation:

• http://www.wisc-online.com/objects/framz.asp?objID=AP2404