Mammalian Lungs

Question 1

Why do aerobic organisms need a constant supply of oxygen?

Answer 1

To release energy in the form of ATP during respiration

Question 2

Why does the carbon dioxide need to be removed during aerobic respiration?

Answer 2

So it doesn’t build up and become harmful for the body

Question 3

Why does carbon dioxide need to be removed?

Answer 3

So there isn’t a build up which is harmful for the body

Question 4

Why are the volumes of oxygen inspired and carbon dioxide expired so large in mammals?

Answer 4

-large organisms with large volume of living cells
- high body temperature maintained due to high respiratory and metabolic rates

Question 5

Why do mammals have lungs?

Answer 5

To ensure efficient gas exchange between the air and their blood

Question 6

Does the pulmonary artery bring blood in or out of the lungs?

Answer 6

Brings DEOXYGENATED blood into the lungs

Question 7

Does the pulmonary vein bring blood into or out of the lungs?

Answer 7

Brings OXYGENATED blood out of the lungs

Question 8

What characteristic of air relates to why the lungs are internal structures?

Answer 8

Air is not dense enough to support the delicate features

Question 9

How does the water potential relate to why lungs are located inside the body?

Answer 9

Without them the body would lose a lot of water and dry out due to a significantly low water potential

Question 10

What feature supports and protects the lungs?

Answer 10

The rib cage

Question 11

What ensures the air in the lungs is constantly replenished?

Answer 11

The lungs are ventilated by a tidal stream of air

Question 12

What moves the ribs?

Answer 12

The muscles between them (intercostal muscles)

Question 13

What two entryways does air enter the lungs?

Answer 13

• nasal cavity
• mouth

Question 14

What are the 5 main features of the lungs?

Answer 14

1) Trachea
2) Bronchi
3) Bronchioles
4) Alveoli

Question 15

What is the purpose of cartilage in the trachea?

Answer 15

Prevents the trachea from collapsing as the air pressure falls inside when breathing in

Question 16

What are the tracheal walls made up of?

Answer 16

Muscle lined with ciliates epithelium and goblet cells

Question 17

What do the bronchi produce to trap dirt particles?

Answer 17

Mucus

Question 18

How is the mucus moved towards the throat to be coughed out?

Answer 18

Cilia

Question 19

Do the larger bronchi have cartilage?

Answer 19

Yea

Question 20

What do the bronchioles branch off from?

Answer 20

The two bronchi

Question 21

What are the bronchioles walls made from?

Answer 21

Muscle lined with epithelial cells

Question 22

Why do the bronchioles have muscle?

Answer 22

So they can constrict and control the flow of air in and out of the alveoli

Question 23

What is the diameter of alveoli? (Interval)

Answer 23

100um < d < 300um

Question 24

What are between the alveoli?

Answer 24

Collagen and elastic fibres

Question 25

What are the alveoli lined with?

Answer 25

Epithelium

Question 26

What is the function of the elastic fibres when inspiring and expiring?

Answer 26

Inspiring - allow alveoli to stretch as they fill with air Expiring - spring back to expel carbon dioxide rich air

Question 27

What does the alveolar membrane act as during gas exchange?

Answer 27

A gas exchange surface

Question 28

Why is air constantly moved in and out of the lungs? (Ventilation)

Answer 28

To maintain diffusion of gases across the alveolar epithelium

Question 29

What occurs during inspiration?

Answer 29

Air pressure of the atmosphere is greater than the air pressure in the lungs so air is forced in

Question 30

What occurs during expiration?

Answer 30

The pressure in the lungs is greater than the pressure in the atmosphere so air is forced out of the lungs