Respiratory System:pp. 885-890

• Pre-Movie:http://kidshealth.org/kid/closet/movies/how_the_body_works_interim.html

• Major structures:– Lungs– Nose– Mouth– Trachea

Respiratory System Functions

• Moves air into and out of lungs• Controls gas exchange between blood and

lungs

Key terms• Pharynx – a muscular tube in the upper throat which serves as a

passageway for air and food• Larynx – a passageway for air, or the voice box, that is located in

the neck• the flap of tissue that covers the opening to the larynx when you

swallow food or liquids is called the epiglottis• Trachea – a long, straight tube in the chest cavity; also referred

to as the windpipe

Key terms• Bronchi – one of the two smaller tubes that the trachea divides

into; this one leads to the lungs • Bronchi divide into smaller tubes called bronchioles and bronchioles

end in clusters of air sacs called alveoli• Alveoli – Clusters of air sacs where gases are actually exchanged• Lungs – among the largest organs in the body, the lungs are

suspended in the chest cavity, bound on the sides by the ribs and on the bottom by the diaphram

• Diaphragm – a powerful muscle spanning the ribcage under the lungs that aids in respiration

Breathing

• The process by which air is drawn into and pushed out of the lungs

• Inhalation – the process of drawing air into the lungs (rib muscles and diaphragm contract)

• Exhalation – the process of breathing out (rib cage and diaphragm muscles relax)

http://kvhs.nbed.nb.ca/gallant/biology/negative_pressure_breathing.html

Summary of the path of oxygen and carbon dioxide through the body

1) Oxygen from the outside air reaches the lungs.2) The oxygen diffuses from the alveoli to the pulmonary capillaries. At the high

oxygen levels that occur in the blood within the lungs, most hemoglobin molecules carry a full load of oxygen.

3) The oxygen-rich blood then travels to the heart. The heart pumps the blood to the tissues of the body.

4) Oxygen diffuses into the cells for use during aerobic respiration. In the tissues, oxygen levels are lower. This causes the hemoglobin to release its oxygen.

5) In tissues, the presence of carbon dioxide produced by cellular respiration makes the blood more acidic and causes the hemoglobin molecules to assume a different shape, one that gives up oxygen more easily. The carbon dioxide diffuses from the cells to the blood.

6) Most of the carbon dioxide travels to the heart as bicarbonate (HCO3- )ions.

7) The heart pumps the blood to the lungs. In the lungs, carbon dioxide is released in its gaseous form to the alveoli.

8) The carbon dioxide is expelled.

What is asthma?

• A chronic condition in which the bronchioles of the lungs become inflamed, because of their sensitivity to certain stimuli in the air.

• The bronchial walls tighten and extra mucus is produced, causing the airways to narrow

• In severe asthma attacks, the alveoli may swell enough to rupture.

• Although asthma can be deadly if left untreated, prescribed medical inhalant medicines may help to stop an asthma attack by expanding the bronchioles.

http://trickledown.files.wordpress.com/2009/04/asthma.jpg

What is emphysema?• A chronic pulmonary disease resulting

from a chemical imbalance that destroys elastic fibers in the lungs (normally these fibers allow the lungs to expand and contract)

• Emphysema begins with the destruction of alveoli– This damage is irreversible and results in

constant fatigue and breathlessness• Severely affected individuals must

breathe from tanks of oxygen in order to live

• Smoking is the cause of up to 90% of emphysema patients

Lung cancer: smoking is the major cause

Respiratory System Activities

• http://msjensen.cehd.umn.edu/WEBANATOMY/timed/36.htm

• http://www.vtaide.com/png/respiratoryF.htm• http://www.getbodysmart.com/ap/respirator

ysystem/menu/menu.html• http://health.howstuffworks.com/adam-2000

20.htm• http://msjensen.cehd.umn.edu/webanatomy/

game/Respiratory.htm