P1+P2 - 2g gas exchange Flashcards
how does the act of Inhalation work?
- air pressure drops and air goes in, the pressure inside the body goes below the atmospheric pressure and air will go in the lungs to equalise it.
what happens when you are breathing out?
it decreases the space in the body (lungs, ribs, muscles) so air goes out
how does the pressure drop in the body?
external intercostal muscles pull the rib cage up and out, at the same time the diaphragm contracts and goes down
- the volume increases in the thorax and therefore the pressure decreases
what happens in exhalation?
the opposite happens in inhalation the internal intercostal muscles aren’t used, in exhalation because gravity is normally enough for normal breathes
- the volume decreases and the pressure increases
- diaphragm goes up
what is ventilation?
breathing in and out
what are the alveolus?
where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out
what are the adaptations of alveolus?
good blood supply
high surface area
very thin and compacted
tube gets folded to increase surface area
how thick are the alveoli?
one cell thick to allow for diffusion
why do the alveoli have good blood flow?
maintains a concentration gradient, it takes away the oxygen so it can keep going
what is the pleural membrane?
is a thin membrane around the lungs that contains the pleural liquid in it
what does the pleural liquid do?
protects the lungs from damage and acts as a lubricant
what are the effects of smoking?
- contains many chemicals
- tar builds up inside the alveoli
- takes away surface area
- causes emphysema
- lungs
what is emphysema?
loss of alveoli
- takes away surface area and destroys alveoli
what is epiglottis?
is the flap that stops the food from going down the trachea
what is the role of diffusion in gas exchange?
it is the process by which gas exchange occurs, it can happen through the cell membrane
