mammalian gas exchange Flashcards
what is breathing
the movement of O2 and CO2 into and out of the lungs
name some of the specialised exchange surfaces
-alveoli in lungs
-small intestine
-liver (adjusts sugar levels)
-root hairs in plants
-hyphae in fungi
what are the alveoli
tiny air sacs which give a large surface area for the diffusion of oxygen
what are the adaptations of the alveoli
-the outside of the alveolus is covered with tiny blood vessels
-alveoli wall is one cell thick
-the wall of the alveoli are moist
what is a surfactant
a complex substance that reduces surface tension by interrupting the hydrogen bonds of water molecules
what does the cartilage do
-provides support
-stops the trachea and bronchi collapsing when pressure drops
what do external intercostal muscles do
-contraction of the external intercostal muscles elevates the ribs and spreads the apart (inhale)
what do internal intercostal muscles do
contraction of the internal intercostal muscles depresses the ribs and pulls them closer together (exhale)
