BRAINCAKEThe Lungs
The lungs are a pair of structures made up of branched tubules called bronchioles which end in tiny air sacs called alveoli
The trachea is a flexible tube that leads to the buccal(mouth) and nasal cavities through which air can flow to and from the external environment.
It is supported by C-rings or incomplete rings of cartilage. The walls are made up smooth muscle lined with ciliated epithelial cells and goblet cells. Goblet cells secrete mucus which traps bacteria and dust particles.
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More in Exchange Surfaces and Breathing
- The Need for Specialised Exchange Surfaces
- Surface Area to Volume Ratio
- Specialised Exchange Surfaces
- The Human Gas Exchange System
- Mechanism of Breathing
- Inspiration
- Expiration
- Alveoli
All 24 lessons in Exchange Surfaces and Breathing · All OCR AS-level Biology topics