Respiratory SystemRespiratory SystemBy Abby Dillard, Leslie Flanders, and Bailey ArrendaleBy Abby Dillard, Leslie Flanders, and Bailey Arrendale

6.4.1 Distinguish between ventilation, gas exchange, and cell respiration

Ventilation - The process of bringing in new air into the alveoli. Ventilation maintains a constant concentration gradient between oxygen and carbon dioxide in the alveoli as well as maintains the concentration gradient between oxygen and carbon dioxide in the capillaries of the blood.

Gas Exchange - The process of exchanging one gas for another. Gas exchange occurs in the alveoli. Oxygen diffuses into the capillaries from the air and carbon dioxide diffuses out of the capillaries in the opposite direction to be expelled.

Cell Respiration - The releasing of energy in the form of ATP. This allows energy to be used inside of the cell. Cell Respiration occurs in the mitochondria and cytoplasm of cells. In this process, oxygen is used and carbon dioxide is produced.

6.4.2 Explain the need for a ventilation system

Ventilation systems are required in order to...

Maintain the concentration gradients between oxygen and carbon dioxide in the alveoli.

The body needs oxygen in order to carry out the process of cell respiration AND the body needs a way to get rid of carbon dioxide, the end product of cell respiration.

Oxygen needs to be able to diffuse from the alveoli into the blood and carbon dioxide needs to be able to diffuse from the blood to the alveoli. In order for this to occur, there must a high oxygen concentration and low carbon dioxide concentration. A ventilation system makes this possible because it brings oxygen into the body and gets rid of carbon dioxide in the alveoli.

6.4.3 Describe the features of the alveoli that adapt them to gas exchange

The large number of alveoli increase the surface area for gas exchange.

The wall of alveoli and the walls of the capillaries are made up of a thin, single layer of cells so the diffusion distance is small which allows for quick exchange of gases.

Alveoli are covered with capillaries. These capillaries allow for oxygen to diffuse in the blood and carbon dioxide to diffuse out of the blood.

Some cells in the walls allow gas to dissolve because the cells secret a fluid. This fluid prevents the multiple alveoli from getting stuck together.

6.4.4 Draw and label a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles, and alveoli

6.4.5 Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by the internal and external intercostal muscles, the diaphragm and abdominal muscles

Inhalation

External intercoastal muscles contract - this moves rib cage up

Diaphragm contracts

The contraction of the rib cage and diaphragm results from an increase in the volume of the thorax which in turn results in a drop in pressure inside the thorax. The pressure will eventually drop below atmospheric pressure.

Air flows from outside of the body -> nose/mouth -> trachea -> bronchi -> bronchioles. Air enters in the lungs until the pressure inside the lungs increases to atmospheric pressure

6.4.5 Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by the internal and external intercostal muscles, the diaphragm and abdominal musclesExhalation

Interal intercoastal muscles contract - this moves rib cage down

Abdominal muscle contracts - causes diaphragm to push back up

Results in a decrease of the volume of the thorax and an increase in pressure in the thorax. The pressure will eventually rise above atmospheric pressure.

Air flows from the lungs to the outside of the body via the nose or mouth. Air will keep flowing until atmospheric pressure is reached.

ELEMENT BASED RESEARCH WITHIN THE PAST YEAR

Asthma is the inflammation of the air passages which results in the narrowing of air passages which makes it difficult to breathe.

Asthma affects effects an estimated 20 million Americans (1 in 15 Americans). Five million of the 20 million Americans that have asthma are people under the age of 18.

Statistics and Images from - “Asthma and Allergy Foundation of America - Information About Asthma, Allergies, Food Allergies and More!" Asthma and Allergy Foundation of America. Web. 29 Apr. 2012. <http://www.aafa.org/display.cfm?id=8>.

ELEMENT BASED RESEARCH WITHIN THE PAST YEARJanuary 2011 Title: Heterogeneity of severe asthma in childhood: Confirmation by cluster analysis of children

in the National Institutes of Health/National Heart, Lung, and Blood Institute Severe Asthma Research Program

Objective: “This study determined how children with severe asthma are distributed across a cluster analysis and how well these clusters conform to current definitions of asthma severity.”

“Statistical classification technique in which cases, data, or objects (events, people, things, etc.) are sub-divided into groups (clusters) such that the items in a cluster are very similar (but not identical) to one another and very different from the items in other clusters. It is a discovery tool that reveals associations, patterns, relationships, and structures in masses of data.” http://www.businessdictionary.com/definition/cluster-analysis.html#ixzz1tTHzECSK

Methods: “Cluster analysis was applied to 12 continuous and composite variables from 161 children at 5 centers enrolled in the Severe Asthma Research Program.”

Results: “Four clusters of asthma were identified. Children in cluster 1 (n = 48) had relatively normal lung function and less atopy. Children in cluster 2 (n = 52) had slightly lower lung function, more atopy, and increased symptoms and medication use. Cluster 3 (n = 32) had greater comorbidity, increased bronchial responsiveness, and lower lung function. Cluster 4 (n = 29) had the lowest lung function and the greatest symptoms and medication use. Predictors of cluster assignment were asthma duration, the number of asthma controller medications, and baseline lung function. Children with severe asthma were present in all clusters, and no cluster corresponded to definitions of asthma severity provided in asthma treatment guidelines.”

Conclusions: “Severe asthma in children is highly heterogeneous. Unique phenotypic clusters previously identified in adults can also be identified in children, but with important differences. Larger validation and longitudinal studies are needed to determine the baseline and predictive validity of these phenotypic clusters in the larger clinical setting.”

Information and Quotes from: Fitzpatrick, Anne M., W. Gerald Teague, Deborah A. Meyers, Stephen P. Peters, Xingnan Li, Huashi Li, Sally E. Wenzel, Shean Aujla, Mario Castro, Leonard B. Bacharier, Benjamin M. Gaston, Eugene R. Bleecker, and Wendy C. Moore. "Heterogeneity of Severe Asthma in Childhood: Confirmation by Cluster Analysis of Children in the National Institutes of Health/National Heart, Lung, and Blood Institute Severe Asthma Research Program." Http://www.jacionline.org. The Journal of Allergy and Clinical Immunology, 03 Jan. 2011. Web. 29 Apr. 2012. <http://www.jacionline.org/article/S0091-6749(10)01765-3/abstract>.