Chapter 11: Gas Exchange

Question 1

Features of Gas Exchange Surfaces

Answer 1

-Large surface area to allow faster diffusion of gases across the surface.
-Thin walls to ensure diffusion distances remain short.
-Good ventilation with air so that diffusion gradients can be maintained.
-Good blood supply to maintain a high concentration gradient so diffusion occurs

Question 2

Part of breathing system

Answer 2

https://cdn.savemyexams.com/cdn-cgi/image/w=1920,f=auto/uploads/2020/01/The-lungs.png

Question 3

function of cartilage in the trachea

Answer 3

it keeps the trachea open and prevents its collapse when air is not passing through it

Question 4

Roles of ribs and intercostal muscles and diaphragm when inhaling

Answer 4

External intercostal muscles contract
Ribs move up and out
Diaphragm contract
More volume and less pressure in thorax

Question 5

Roles of ribs and intercostal muscles and diaphragm when exhaling

Answer 5

Internal intercostal muscles contract
Ribs move down and in
Diaphragm relaxed
Less volume and more pressure in thorax

Question 6

Explain the differences in composition between inspired and expired air

Answer 6

Inspired Air: Contains about 21% oxygen and 0.04% carbon dioxide. Water vapor variable
Expired Air: Has roughly 16% oxygen and 4% carbon dioxide. Water vapor saturated
Same nitrogen

Question 7

Explain the link between physical activity and the rate and depth of breathing

Answer 7

an increased carbon dioxide concentration in the blood, which is detected by the brain, leading to an increased rate and greater depth of breathing

Question 8

role of goblet cells, mucus and ciliated cells in protecting the gas exchange system for pathogens and particles

Answer 8

Goblet cells make sticky, slimy mucus.
Many of the bacteria in the air and dust particles get trapped in the mucus
Ciliated cells have tiny, microscopic hair on them called cilia
The cilia sweep the mucus upwards, towards the back of the throat