Gas Exchange Rebekah Kim Pranathi Rao AP Biology Period 0-1

Well... did you think that gas exchange involved burping and farting?

In case you didn't know what farting sounds likes... xI-U

What is gas exchange? That's what we thought too... BUT gas exchange is ACTUALLY the uptake of molecular oxygen from the environment and the discharge of carbon dioxide to the environment.

Evolutionary Aspect When earth was first created oxygen didn't exist. In fact, oxygen came to existence 2.7 billion years ago. Therefore, gas exchange emerged with the arrival of oxygen. Since there was a scarcity of oxygen, natural selection favored organisms which were able to utilize the oxygen the most efficiently.

Evolutionary Aspect Primitive invertebrates such as sponges, cnidarians, flatworms, and roundworms exchange gases with diffusion. Segmented worms are too large to be sustained by diffusion alone. o Uses their skin as an initial gas exchange surface, but then uses blood to deliver the gases to and from their body cells.

Why is gas exchange necessary? oUhU

Gas exchange is important because... It allows for the transfer of oxygen from the surroundings to individual cells in the body needed for respiration. o This process produces energy that is essential for the organism to survive. If carbon dioxide wasn't removed from the body by gas change, it would be harmful. Ultimately, without the gas exchange we would die from lack of oxygen.

Respiratory Surface Major Structures...

Diffusion... Gas exchange is fast when the area of diffusion is large and the path for diffusion is short so the structure of a respiratory surface is usually large and thin.

Major structures... Larynx

Major Structures... Trachea

Lungs Major Structures...

Alveoli

Major Structures... Gills

The effect of having gills... BcnDI

The interdependence of the gas exchange... Gas exchange depends on the functioning of the respiratory as well as the circulatory system. The respiratory system helps exchange the intake of oxygen with carbon dioxide The circulatory system allows the oxygenated blood to travel throughout the body.

Major Structures... Heart

Breathing Mechanisms... How a mammal breathes: Mammals employ negative pressure breathing. Mammals lower air pressure in their lung below that of the air outside their body. How an amphibian breathes: An amphibian employs positive pressure breathing. The air goes through the nostrils and is forced down the trachea and is released by the lungs and muscular body wall.

Diseases/Disorders Asthma o A chronic lung disease that inflames and narrows the airways.  The airways become swollen and the muscles tighten, which triggers the symptoms. o It causes recurring periods of wheezing, chest tightness, shortness of breath, and coughing. o Asthma can start at any age, but usually develop when people are young. o Asthma is caused by genetics, allergies, respiratory infections, and the environment.

Diseases/Disorders Emphysema o A lung disease that makes it hard to breathe. o It occurs when the air sacs in the lungs are gradually destroyed, which leaves the person more short of breath. o As it worsens, emphysema reduces the surface area of the lungs and the amount of oxygen that reaches the bloodstream.  Smoking is the major cause of emphysema.

Diseases/Disorders Pneumonia o A common lung infection caused by bacteria, a virus or fungi. o The alveolar spaces fill with mucus, inflammatory cells, and fibrin.  Causes: viruses, adenoviruses, rhinovirus, influenza virus (flu), respiratory syncytial virus, and parainfluenza virus.  Symptoms: fever, chills, cough, chest pain, rapid breathing, nasal congestion, wheezing, etc.

Diseases/ Disorders Hypoventilation o This is the result of an insufficient exchange of gases. o This leads to increased levels of carbon dioxide in the blood. o It can be caused by natural barriers in the airway as well as through resistances to adequate airflow. o Symptoms can include: headaches, heart problems, stomach problems and faintness.  It can also lead to poor sleep due to constant awakeness and result in daytime sleepiness.

Diseases/Disorders Hyperventilation o A respiratory disorder, which is associated with rapid or deep breathing that can occur with anxiety or panic. o This causes an excessive release of carbon dioxide. o It reduces the CO 2 concentration of blood to below its normal level and raises the blood's pH level.  Common causes: stress and anxiety  Symptoms: numbness or tingling in the hands, feet and lips; lightheadedness, dizziness, headache, chest pain, spasm, slurred speech, nervous laughter, and sometimes fainting.

So... What is the difference between HYPERventilation and HYPOventilation? - HYPERventilation is a state in which there is excessive breathing that causes CO 2 blood levels to become too low. - HYPOventilation is a result of inadequate gas exchange where not enough oxygen is taken in and not enough carbon dioxide is exhaled, leading to CO 2 buildup in the blood.

TO: Mrs. Said (from: the class) Hyperventilation is a respiratory disorder caused by stress and this project has given all of us so much stress so please Mrs. Said for the sake of our lungs please give us an A.

Gas Exchange Questions 1. The rate of diffusion is _________________ proportional to the surface area of the respiratory surface and ___________________ proportional to the square of the distance. a. directly, directly b. inversely, directly c. directly, inversely d. inversely, inversely e. None of the above

More Gas Exchange Questions 2. How much oxygen is found in the air? a. 15% b. 21% c. 47% d. 65% e. 74%

Gas Exchange FRQ Describe how the circulatory and the respiratory systems allow gas exchange to occur.

WebSites fm?id=origin-of-oxygen-in-atmosphere C / reference/gas-exchange ks/martini10/chapter24/custom2/deluxe- content.html

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