Chapter 7

Question 1

4 features of exchange surfaces

Answer 1

Increased SA

Thin Layers

Good Blood Supply

Ventilation

Question 2

Why is increasing SA a feature

Answer 2

Provides a higher area for exchange and overcome the limitations of SA:V ratio

Question 3

Why is thin layers a feature

Answer 3

Substances diffuse shorter

Process is faster

Question 4

Why is good blood supply a feature

Answer 4

Steeper concentration gradient which means faster diffusion

Question 5

Why is ventilation a feature

Answer 5

Helps to maintain concentration gradient

Question 6

3 features of the naval cavity explained

Answer 6

A large surface area and good blood supply
—To warm up the air

Hairy lining
—Protection

Moist Substances
—Increases humidity to prevent evaporation

Question 7

What is the trachea

Answer 7

Main airway carrying clean, warm, moist air from the nose down into the chest

Question 8

2 features of the trachea

Answer 8

Wide tube supported by incomplete rings of cartilage

Goblet cells and ciliated epithelium

Question 9

Why are there incomplete rings in the trachea

Answer 9

So food can travel

Question 10

What are the size of the alveoli

Answer 10

200-300um

Question 11

Explain Inspiration in 5 Steps

Answer 11

1)Lungs inhale

2)Diaphragm contracts flattens and lowers

3)External Muscles contract and internal muscles relax

4)Volume of the Thorax increases and pressure decreases

5)Air rushes in and fills the lungs

Question 12

Explain Exhalation in 6 steps

Answer 12

1)Lungs Exhale

2)Diaphragm relaxes so the ribs move down and inwards

3) Internal muscles contract external muscles relax

4)Elastic fibres in the alveoli return to original length

5)Pressure increases and volume decreases

6)Air comes out of the lungs

Question 13

What is vital capacity

Answer 13

The maximum volume of air that can be inhaled or exhaled in a single breathe

Question 14

What is tidal volume

Answer 14

The volume of air we breathe in and out at each breathe at rest

Question 15

Inspiratory Reserve Volume

Answer 15

Maximum air breathed in

Question 16

Expiratory Reserve Volume

Answer 16

Maximum air breathed out

Question 17

Residual Volume

Answer 17

Air left in lungs

Question 18

Total Lung Capacity

Answer 18

Sum of vital capacity and residual volume

Question 19

How to calculate ventilation rate

Answer 19

tidal volume x breathing rate

Question 20

Explain Gas Exchange in Insects in 5 points

Answer 20

1)Spiracles open

2)Air travels into spiracles then tracheae and tracheoles

3)Oxygen diffuses into the tracheoles

4)CO2 moves from body to spiracles and out of body

5)Spiracles close

Question 21

How are spiracles opened and closed

Answer 21

By Sphincters

Question 22

Why is the tracheal fluid important

Answer 22

Only allows oxygen to be diffused into the tracheoles

Question 23

What is gas exchange in fish with 4 points

Answer 23

1)Fish opens mouth and lowers the buccal cavity

2)Fish closes mouth and the buccal cavity raises

3)Water goes over the gills due to pressure between the mouth cavity and the operculum caivty

4)Oxygen diffuses