1. What is the role of cilia in the trachea?
- Help the trachea contract
- Waft mucus up the airway to the back of the throat
- Secrete mucus to trap particles
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Other questions in this quiz
2. What are the walls of the trachea made up of?
- Goblet cells
- Smooth muscle
- Elastic fibres
- Ciliates epithelium
3. Why does blood bring CO2 to the lungs?
- Maintain diffusion gradient
- To increase the concentration of CO2 in the alveolus
- Reduce diffusion distance
- So gaseous exchange is faster
4. How does the capillary wall reduce diffusion distance?
- One cell thick
- Few cells thick
- Flattened or thin cells
5. Smooth muscle mainly makes up what wall in the respiratory system?