the lungs Flashcards
thorax
top part of body
what are the lungs separated from the lower part of body by?
the diaphragm
what are the lungs protected by?
the ribcage
what are the lungs surrounded by?
pleural membranes
describe the structure of the lungs
-air goes through the trachea
-trachea splits into bronchi, one going to each lung
-bronchi splits into smaller tubes called bronchioles
-bronchioles end at small air sacs called alveoli
which organ system are the lungs part of?
respiratory
single of bronchi and alveoli
bronchus, alveolus
how are alveoli adapted for gas exchange?
-one cell thick walls which provides a short diffusion distance
-millions of alveoli gives the lungs a large surface area
-moist to allow the gases to dissolve and diffuse more easily
-surrounded by a network of capillaries, giving it a good blood supply
-high concentration gradient
what diffuses out of the alveoli into the blood?
oxygen
what diffuses in to the alveoli to be breathed out?
carbon dioxide
describe how the alveoli have a high concentration gradient
-blood just returned to the lungs from the rest of the body
-so contains lots of CO₂ and little oxygen
-oxygen diffuses out of the alveolus at a high concentration to the blood with a low concentration
-CO₂ diffuses out of the blood at a high concentration into the alveolus at a low concentration
where are the lungs found?
located in the thorax within the chest
explain how the lungs are ventilated when air moves in and out
IN:
1. intercostal muscles contract
2. ribcage moves upwards and outwards
3. diaphragm flattens and volume of the chest increases
4. increased volume results in decreased pressure
5. air is drawn into lungs down pressure gradient
INVERSE OCCURS WHEN MOVING OUT
describe how gas exchange occurs at the alveoli
-oxygen diffuses from alveoli into the capillary bloodstream down concentration gradient
-carbon dioxide diffuses from from the capillary into the alveoli down its concentration gradient
how can you calculate breathing rate?
number of breaths/number of minutes
