human gas exchange Flashcards
define breathing?
movement of air into and out of the lungs
define ventillation ?
scientific word for breathing
define respiration ?
the chemical reaction to release energy in the form of ATP
define gaseous exchange
diffusion of oxygen from the air in the alveoli into the blood and of carbon dioxide from the blood into the alveoli
where is the diaphragm ?
underneath the lungs
what happens when the external intercostal muscles contract?
pulls rib cage up and cut leading to bigger volume in thorax and inspiration
what happens when internal intercostal muscles contract ?
pull ribcage in and down so decreases thoratic cavity volume expiration
when does the diaphragm contract and relax?
contracts in inspiration and relaxes in expiration
how does air move in inspiration ?
from atm to lungs down pressure gradient gradient
how does air move in expiration ?
from high pressure in lungs to atm down concentration gradient
where are alveoli?
end of bronchioles
what is alveoli structure ?
single layer of cells surrounded by capillary network of single layer of cells
what does alveolie allow ?
simple diffusion of carbon dioxide out and oxygen in
how are alveoli adapted ?
300 million= large surface area
epithelium cells are very thin = short diffusion pathway
network of capillaries = maintains concentration gradient
