3.1.1: Mammalian Gas Exchange

Question 1

What is the primary function of cartilage in the trachea?

Answer 1

To provide support and prevent collapse during decreased pressure

Cartilage forms C-shaped rings that support the trachea.

Question 2

List the structures involved in the route that air takes during ventilation.

Answer 2

• Nasal cavity
• Pharynx
• Larynx
• Trachea
• Bronchi
• Bronchioles
• Alveoli
• Lungs

These structures make up the upper and lower respiratory tracts.

Question 3

True or False: The esophagus lies directly next to the trachea.

Answer 3

True

The esophagus is adjacent to the trachea, allowing for proper digestion.

Question 4

What type of epithelium lines the trachea?

Answer 4

Ciliated epithelium with goblet cells

This structure helps in trapping dust and pathogens.

Question 5

What is the role of goblet cells in the trachea?

Answer 5

To release mucus that traps dust and pathogens

The mucus is cleared by ciliated epithelial cells towards the mouth.

Question 6

Fill in the blank: The lumen of the trachea can constrict and dilate due to _______.

Answer 6

Smooth muscle and elastic fibres

The smooth muscle contracts to reduce airflow and relaxes to increase airflow.

Question 7

What happens to the lumen of the trachea when harmful substances are detected in the air?

Answer 7

It constricts, reducing airflow into the lungs

This reaction is due to the contraction of smooth muscle.

Question 8

What are the components of the tracheal wall?

Answer 8

• Hyaline cartilage
• Smooth muscle
• Elastic fibres
• Submucosa
• Adventitia

These components provide structure and flexibility to the trachea.

Question 9

What is the purpose of the elastic fibres in the tracheal wall?

Answer 9

To allow stretch and recoil of the lumen

This elasticity helps in regulating airflow.