Gas Exchange in Humans Flashcards
what are the main components of the human gas exchange system
alveoli
bronchioles
bronchi
trachea
lung
describe the structure of the human gas exchange system
there are two lungs
the trachea is the windpipe that leads down to the lungs as it branches off into bronchi which then brand off into bronchioles which then branch off into alveoli
what is inspiration
breathing in
what is expiration
breathing out
what is thoracic cavity
the space where the lungs are
what muscles are involved in ventilation
diaphragm
antagonistic intercostal muscles
during inspiration, how do the internal and external intercostal muscles move
internal: relax
external: contract
how do the ribs react to the contraction of external intercostal muscles
they pull upwards and outwards
movement of diaphragm during inspiration
contracts (downwards from dome position)
what happens to air pressure in lungs during inspiration and why
decreases as air moves in because theres a bigger volume
what happens to lung volume during inspiration
increases
how does air move during inspiration
into the lungs
- higher pressure outside than inside the lungs
during expiration what do the internal and external intercostal muscles do
internal: contract > pull ribs down and inwards
external: relax
how does the diaphragm muscle react o expiration
moves back into original dome position
what happens to air pressure in lungs during expiration
drops as air moves out of
what happens to lung volume during expiration
decreases
how does air move during expiration
air moves out of lungs from high pressure to low pressure
which gases exchange in the alveoli
CO2 into the alveoli
O2 out of the alveoli
how is alveoli adopted for gas exchange
one cell thick > short diffusion pathway
lots of alveoli > large SA
network of capillaries > maintains conc gradient
whats the alveolar epithelium
the walls of the alveoli which is made up of epithelial cells
