Download Edward McRowan, Justin Hagenburg, Caussin Carter, Ethan

Edward McRowan, Justin Hagenburg, Caussin Carter, Ethan Thompson, Jordan Arroyo
Alveoli Gas Exchange
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Nasal Cavity/Mouth Cavity > Epiglottis > Trachea > Bronchus > Bronchioles >
Alveolus > diaphragm
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Air enters the nasal cavity and is moistened, warmed, and filtered. Then the air passes
through the larynx and down the trachea and bronchi into the bronchioles. The
bronchioles end in microscopic air sacs known as alveoli where diffusion of respiratory
gases occurs.
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The epiglottis directs air down the trachea, which is the most direct pathway to the
lungs. The lungs are not hollow sacs but are instead filled with folds of tissue that
greatly increase surface area. Bronchus run along the folds and branch into
bronchioles which have alveoli attached to them.
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Lungs evolved to have greater surface area in order to sustain larger organism, which
require more oxygen.
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This is paralleled in other transport systems such as the way that villi need a greater
surface area to transport nutrients from food into the blood stream.
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The lungs exist within the internal respiratory surface, which is increased in volume
when air is taken in, the lungs expand and the diaphragm contracts and lowers. The
alveoli expand when air is taken in and O2 is stored until it diffuses into the blood
stream.
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The majority of oxygen is not carried by hemoglobin, but by plasma.
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When it is carried by hemoglobin, the compound turns into oxyhemoglobin.
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Hemoglobin is allosteric (it changes shape to more easily bind with oxygen
molecules).
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Arteries branch off into capillaries that wrap around the alveoli in order to ease the
process of diffusion. CO2 is then diffused from the capillaries back into the alveoli so
that it can be exhaled back out.
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Plasma aids in the osmoregulation of CO2 that exits the alveoli.
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Alveoli have a surface area of about 100m2
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Sponges and hydra have their entire surface area that comes in contact with the
environment aid in gas exchange.
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Circulatory system in order to move the oxygen around the body.
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Nervous system: Medulla aids in the pacing of breathing.
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Skeletal system: guards it and produces red blood cells.
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Muscular system: provides the diaphragm which aids in the expansion of the lungs.
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Asthma… Respiratory condition marked by spasms in the bronchi of the lungs causing
difficulty in breathing it usually results from an allergic reaction or other forms of
hypersensitivity.
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Emphysema is… the damaging of the alveoli causing breathlessness.
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Both CO2 and O2 passively diffuse.
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Terrestrial an aquatic mammals
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Plants diffuse through pores on leaves.
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Unicellular organisms simply absorbs oxygen and diffuses the carbon dioxide
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Plants air diffuses in and out of the plant through pores on the leaves. Inside the leaf there are air
spaces for the spongy mesophyll to absorb it and process the co2 and release the o2.
Edward McRowan, Justin Hagenburg, Caussin Carter, Ethan Thompson, Jordan Arroyo

Animals like fish must use gills to absorb oxygen dissolved in the water. Gills are organs that are
made of filaments and lamellae, which contain capillaries and have a very large surface area and a
short diffusion area.