2.8 Gas exchange

Question 1

alveoli

Answer 1

tiny air sacs in the lungs at the end of the bronchioles where gas exchange occurs
adapted by having:
thin moist walls for short diffusion distance
folded walls for larger surface area
capillaries close by to maintain a high concentration gradient

Question 2

bronchi

Answer 2

airways branching from the trachea that lead into the lungs

Question 3

bronchioles

Answer 3

small airways branching from each bronchi in each lung

Question 4

capillaries

Answer 4

thin, narrow blood vessels where the exchange of substances between the blood and tissue occurs

Question 5

diaphragm

Answer 5

muscle that contracts and relaxes to change the volume of the thorax and ultimately the pressure to control inhalation and exhalation

Question 6

intercostal muscles

Answer 6

muscles between the ribs that contract and relax to move the ribcage and change the volume and pressure during inhalation and exhalation

Question 7

pleural membrane

Answer 7

airtight membranes covering the lungs and the thorax to maintain pressure changes and stop the lungs from sticking to the ribcage

Question 8

ribs

Answer 8

help to protect the organs in the thorax

Question 9

What happens to the diaphragm during inhalation?

Answer 9

contracts
moving down and flattening

Question 10

What happens to the intercostal muscles during inhalation?

Answer 10

contract
moving rib cage up and out

Question 11

What happens to the volume and pressure during inhalation?

Answer 11

volume - increases
air pressure - falls

Question 12

What happens to the diaphragm during exhalation?

Answer 12

relaxes
moving up and becoming dome-shaped

Question 13

What happens to the intercostal muscles during exhalation?

Answer 13

relax
moving rib cage down and in

Question 14

What happens to the volume and pressure during exhalation?

Answer 14

volume decreases
air pressure rises