function of the respiratory system Flashcards
what process allows gas exchange to occur in the lungs
by diffusion
what type of transport is diffusion
passive
when does the rate of diffusion increase
when distance between blood cells decrease
what happens during diffusion in the respiratory system
oxygen in lungs move towards the blood and co2 in the blood moves to the lungs
blood has a low concentration of oxygen compared to what
inhaled air in alveoli which has high concentration of co2 compared to the capillaries
how do the molecules move from
area of high concentration to low concentration
what allows diffusion
thin alveolar epithelium
how is the concentration of co2 reversed
reversed in their location compared to oxygen levels
what do the capillaries contain high levels of
co2
what do the alveoli contain high levels and low levels of
high oxygen and low co2
where does carbon dioxide diffuse
into the alveoli
where does oxygen diffuse
capillaries
what does inhalation do
brings in oxygen
what does exhalation do
brings out co2
what does ventilation occur as
combination of muscle action and negative pressure
what does the diaphragm and intercostal muscles between the ribs do
contract simultaneously to increase volume of the lungs
what does the contraction of the diaphragm and intercostal muscles do
decreases pressure in lungs and draws in air
what happens when the diaphragm and intercostal muscles relax
causes reduction in lung volume and increase pressure in lungs causing air to be pushed out
what is periodic inhalation
inhalation of air
what is expiration
expulsion of air
what does periodic inhalation and expiration do
clears out air rich in co2 and replaces it with air rich in oxygen
what is tidal volume
the amount of air breathed in and out during a normal breath
what is residual volume
small amount of air rich in co2 remains trapped in alveoli after expiration and mixes with air rich in oxygen brought in during inspiration
what are the breathing control centers in the brain
medulla oblongata
