Structure Of The Human Gas Exchange System

Question 1

Why is the volume of oxygen absorbed and the volume of co2 removed large in mammals ?

Answer 1

They are relatively large organisms with a large volume of living cells

They maintain a high body temperature which is related to them having high metabolic and respiratory rates

Question 2

Why are lungs located inside the body

Answer 2

Air is not dense enough to support and protect these delicate structures

The body as a whole would otherwise lose a great deal of water and dry out

Question 3

What’s the structure and function of the lungs

Answer 3

Made up of highly branched tubules called bronchioles, which end in tiny air sacs called alveoli

Question 4

What’s the structure and function of the trachea

Answer 4

Flexible airway that is supported by rings of cartilage

Which prevents the trachea collapsing as the air pressure inside falls when breathing in

Question 5

What’s the structure and function of the bronchi

Answer 5

Two divisions of the trachea, each leading to one lung

Produce mucus to trap dirt particles and have cilia that move the dirt laden mucus towards the throat

Question 6

What’s the structure and function of the bronchioles

Answer 6

Series of branching subdivisions of the bronchi

Walls made of muscle lines with epithelial cells - allowing them to constrict so that they can control the flow of air in and out of the alveoli

Question 7

What’s the structure and function of the alveoli

Answer 7

Minute air sacs at the end of bronchioles

Between alveoli there is collagen and elastic fibres - allow alveoli to stretch as they fill with air when breathing in

Question 8

State 2 reasons why humans need to absorb large volumes of oxygen from the lungs

Answer 8

Humans have a large volume of cells

High metabolic rate

High body temp

Question 9

List in sequence all the structures that air passes through on its journey from the gas exchange surface of the lungs to the nose

Answer 9

Alveoli, bronchioles, bronchus, trachea, nose

Question 10

Explain how cells lining the trachea and bronchus protect the alveoli

Answer 10

Cells produce mucus that traps air particles of dirt and bacteria in the air breathed in

Cilia on these cells move this debris up the trachea and into the stomach

The dirt/bacteria could cause infection in the alveoli