AP BIOLOGY

Detailed explanation-1: -The trapped dust and the mucus are constantly moved towards the upper airway (nose and mouth) in a sweeping motion to be expelled by tiny hair-like structures called cilia.

Detailed explanation-2: -Your trachea is a key part of your respiratory system. The trachea is made of rings of cartilage. It is lined with cells that produce mucus. This mucus keeps allergens, dust particles or other debris out of your lungs.

Detailed explanation-3: -Cilia propel a liquid layer of mucus that covers the airways. The mucus layer traps pathogens (potentially infectious microorganisms) and other particles, preventing them from reaching the lungs.

Detailed explanation-4: -The nasal cavity and mouth join at the area in the back of the throat called the pharynx (FAR-inks). The pharynx is part of two body systems (the respiratory system and the digestive system) because it carries both air and food.