gas exchange in the lungs

Question 1

stage 1

Answer 1

air passes through the trachea
rings of cartilage prevent trachea from collapsing after inhalation

Question 2

stage 2

Answer 2

the trachea splits into two smaller tubes called bronchi with one passing into each lung

Question 3

stage 3

Answer 3

further in the bronchi subdivide into bronchioles which are smaller tubes
they end in tiny air sacs called alveoli

Question 4

how many alveoli do the lungs have and what r their size

Answer 4

the lungs have a lot of alveoli which are microscopic

Question 5

what happens in alveoli

Answer 5

in an alveolus oxygen from the air diffuses into the blood-stream, blood diffuses in co2

Question 6

adap 1: surface area

Answer 6

the millions of alveoli give the lungs a huge surface area

Question 7

adap 2: walls

Answer 7

alveoli have very thin walls so diffusion path is very short

Question 8

adap 3: supply

Answer 8

alveoli have a very good supply of blood

Question 9

once oxygen is diffused into the blood-

Answer 9

once oxygen is diffused into the blood its rapidly removed, ensuring the concentration gradient is as steep as possible

Question 10

how do we increase the rate of diffusion by breathing

Answer 10

by breathing we increase the rate of diffuison because breathing brings fresh oxygen into the alveoli and takes away the carbon dioxide, making the concentration gradient high and increases rate of diffusion