Organs in the RS

Question 1

Nose and Nasal Cavity

Answer 1

Air passes through the nose and mouth into the RS

Tiny hairs and mucus in the nose trap dust particles in the air to prevent them entering the lungs

Question 2

Trachea

Answer 2

Air flows down the trachea from the nose into the lungs

The trachea is reinforced by cartilage rings

Lined with hair to move dust particles back out the airways

The trachea divides into 2 large tubes called bronchi and goes to the lungs

Question 3

Bronchi (singular = Bronchus)

Answer 3

One bronchus goes from the trachea to each lung

The bronchi also produce mucus to trap dust particles

Inside the lungs -> the bronchi divide into many smaller branches called bronchioles

Question 4

Bronchioles and Alveoli

Answer 4

Air flows in these bronchioles (tiny tubes) to each alveolus

Alveoli are tiny air-filled sacs that are surrounded by small blood vessels called capillaries

The walls of the alveoli are very thin so gases can cross between the capillaries and air sacs

Question 5

Diaphragm

Answer 5

The diaphragm contracts to expand the space inside the thoracic cavity

While this is happening, the muscles between the ribs (intercostal) also contract

This moves the rib cage up and out

The contractions force air into the lungs, by creating a negative pressure through expansion