Chapter 3 - Breathing And Gas Exchange

Question 1

What is the job of the larynx

Answer 1

The voice box

Question 2

What is the trachea

Answer 2

Windpipe
Surrounded by muscles and c shaped rings of cartilage
C rings so that food can be pushed down the oesophagus

Question 3

Waht is the lungs

Answer 3

Where gas exchange takes place
Large surface area
Close contact with bloodstream - easy for diffusion of gas exchange

Question 4

What is the bronchi

Answer 4

What the trachea branches into
Each bronchus leads to a lung
Supported by cartilage

Question 5

Waht are the Bronchioles

Answer 5

When the bronchus divides into smaller tubes

Where some gas exchange takes place

Question 6

Waht is the alveoli

Answer 6

At eye end of the bronchioles are groups of tiny air sacks (alveoli)
Gives lungs huge surface are
Makes gas exchange efficient

Question 7

What is the heart

Answer 7

Pumps blood around the body

Question 8

What is the diaphragm

Answer 8

Large sheet of muscle under the lungs
Contracts during inhalation- Fattens in shape to increase the size of the chest cavity
During passive exhalation it relaxes and allows the lungs to shrink

Question 9

Waht does the rib cage do

Answer 9

Lifts up and out during inhalation -> increases volume of chest cavity
1st and 12th ribs are fixed with others pivoting according to the action of the intercostal muscles

Question 10

What do the intercostal muscles do

Answer 10

Help move the ribs up and down during breathing

Question 11

What do external intercostal muscles do

Answer 11

Contract to pull ribs upward during inhalation
The first band is anchored to the first rib which is fixed
Each subsequent lifts up the next rib up form above

Question 12

What do the internal intercostal muscles do

Answer 12

Are involved in exhalation - pull the ribs downwards and in

Question 13

Waht happens during inhalation

Answer 13

External intercostal muscles contract
Volume of the chest increases
Diaphragm contracts and flattens
Air is drawn into the lungs
Pressure inside the chest decreases below outside
Internals intercostal muscles relax
Ribs move upwards and outwards

Question 14

What happens during exhalation

Answer 14

External intercostal muscles relax
Air is forced out of the lungs
Volume of the chest decreases
Pressure inside the chest increase above outside
Diaphragm relaxes and moves upwards
Ribs move downwards and in
Internal intercostal muscles contract

Question 15

Name a difference between inhaled and exhaled air

Answer 15

Exhaled is warmer and contains water vapour

Question 16

Parts of the respiratory system top to bottom

Answer 16

Larynx
Trachea
Lung
Intercostal muscle 
Rib
Bronchus
Bronchioles
Heart
Alveolus
Diaphragm

Question 17

Waht is the pleural cavity

Answer 17

The space between two thin membranes called the pleural membranes which is filled with pleural fluid.
Pleural fluid acts as a lubricant and prevents the lungs from sticking to the chest when we breathe

Question 18

Why does breathing rate need to increase during exercise

Answer 18

• muscles are working harder
• more energy needed
• glucose in cells need to be Broken down to release energy
• respiration needs to therefore occur
• more oxygen neede for the is to take place

Question 19

Why does breathing rate not return to normal straight after exercise

Answer 19

• this is because some glucose has broken down by anaerobic respiration during activity so lactic acid is formed
  This lactic air needs to break down so oxygen is required to do this repaying oxygen debt