Gas Exchange in Mammals

Pregunta	Respuesta
What are the steps in the mechanism of gas exchange in mammalian lungs? [6]	Nostril ¦ Nasal Cavity ¦ Trachea ¦ Bronchi ¦ Bronchioles ¦ Alveoli
Why must gases be exchanged in such high volumes in humans? [2]	1~ Humans have a small surface area:volume ratio. 2~ Humans are warm blooded and require high metabolic and respiratory rates.
How is diffusion made efficient across the alveoli? [4]	[] Red blood cells are flattened against the wall of the capillaries [] Breathing/blood flow maintains concentration gradient [] Alveoli/capillaries have large SA:V ratio [] Alveoli/capillaries have thin walls
Explain, step-by-step, the mechanism of inhalation. [7]	~ Internal intercostal muscles relax ~ External intercostal muscles contract ~ Ribs are pulled upwards and outwards ~ The diaphragm flattens ~ The volume of the thorax increases ~Pressure in lungs < Atmospheric pressure ~ Air is forced into the lungs
Explain, step-by-step, the mechanism of exhalation. [7]	~ Internal intercostal muscles contract ~ External intercostal muscles relax ~ Ribs move downwards and inwards ~ The diaphragm domes ~ The volume of the thorax decreases ~Pressure in lungs > Atmospheric pressure ~ Air is forced out of the lungs

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	Creado por Melissa O'Mahony hace más de 7 años