The gaseous exchange system

Question 1

As mammals breath in the air enters the windpipe which is also known as what?

Answer 1

Trachea

Question 2

The trachea splits into how many bronchus?

Answer 2

2

Question 3

Each bronchus leads into what ?

Answer 3

One lung each

Question 4

Each bronchus then branches off into smaller tubes knows as what?

Answer 4

Bronchioles

Question 5

The bronchioles end in small “air sacs” known as what?

Answer 5

Alveoli and this is where gases are exchanged

Question 6

The ribcage, intercostalmuscles and what all work together to move air in and out?

Answer 6

The diaphram

Question 7

Alveoli are surrounded by what?

Answer 7

A network of capillaries, giving each alveolus its own blood supply

Question 8

What are the top three things about the Alveoli structure?

Answer 8

• Each alveolus is made from a single layer of thin, flat cells called the alveolar epithelium
• The walls of the capillary are made from capillary endothelium, also another type of epithelium
• The walls of the alveoli contain elatic fibres. These help the alveoli to return to their normal shape after inhaling and exhaling.

Question 9

How many cells thick are the alveolar epithelium and the capillary endothelium ?

Answer 9

Just on cell thick which creates a short diffusion pathway

Question 10

The alveoli always have a good blood supply from capillaries which ensures a what?

Answer 10

a good conentration gradient

Question 11

What else other than the capillaries helps keep a good concentration gradient?

Answer 11

The diaphram and the the intercostal muscles; they are involved in ventilation which keeps the concentration gradient of oxygen and carbon dioxide high

Question 12

Name the 5 features that help to increase the efficiency of the gaseous exchange system in mammals…

Answer 12

Goblet cells
Cilia
Elastic fibres
Smooth muscle
Cartilage

Question 13

What do goblet cells do?

Answer 13

They secrete mucus which then traps microorganisms and dust particles in the inhaled air stopping them from reaching the alveoli

Question 14

What are cilia?

Answer 14

Hair-like structures on the surface of epithelial cells, they beat the mucus which in turn moves the the mucus upwards away from the alveoli towards the throat where it is swallowed (this helps prevent lung infection

Question 15

What do elastic fibres do?

Answer 15

Help the proces of breathing out, on breathing in the lungs inflate and the elastic fibres are stretched then the fibres recoil to help push the air out when exhaling

Question 16

What does the smooth muscle do?

Answer 16

Allows the diameter of the airways to be controlled, during exercise the smooth muscle relaxes making the tubes wider and therefore results in less resistance to airflow

Question 17

What does cartilage do?

Answer 17

Cartilage in the trachea and bronchi provide them with support, it is strong yet flexible. It stops the trachea and bronchi collapsing when you breathe in and the pressure drops