Respiratory System Structure and Function

Question 1

Nose

Answer 1

Nasal cavity is lined by mucous membranes: As air passes over membranes, it is warmed and humidified. Hairs and mucous line the nose to trap debris preventing them from reaching the lungs.

Question 2

Pharynx

Answer 2

The throat - the region from nasal cavity to top of trachea or oesophagus. Air travels through before being diverted into trachea by epiglottis.

Question 3

Epiglottis

Answer 3

Flap of cartilage. During inhalation, epiglottis covers oesophagus and when swallowing, epiglottis covers larynx.

Question 4

Larynx

Answer 4

Cartilage structure joining pharynx and trachea. Contains vocal cords, also known as voice box. Mucous membranes vibrate as air passes.

Question 5

Trachea

Answer 5

Also called the windpipe, because it carries air into and out of lungs. Made of c-shaped cartilage holding structure open. At the base, trachea splits into two branches each taking air into both lungs. Trachea has epithelial lining able to trap dust and debris.

Question 6

Bronchi

Answer 6

End of trachea, splits into two primary bronchi. Split further into secondary bronchi which takes air into each lobe of lung. After is tertiary bronchi. Structures similar to traches with c-shaped cartilage. As bronchi gets smaller, cartilage spread out with smooth muscle and elastin. Trachea, cilia and mucous work together to trap and remove dust and other particles from airway.

Question 7

Bronchioles

Answer 7

When the tertiary bronchi divide, they form smaller airways called bronchioles which continue to split until they end in millions of terminal bronchioles. They do no contain cartilage but make of smooth muscle and elastin. Allows the flow of air in the lungs to be controlled, expanding when needed more oxygen. Cilia and mucous also present in bronchioles protecting lungs from contaminants.

Question 8

Lungs

Answer 8

2 lungs take up chest cavity except space between them called mediastinum which is occupied by heart and blood vessels. Each lung divided into loves. Left lung has two lobes and tight lung has three. membrane called pleura covers surface of lungs. The visceral pleura (outer) and parietal pleura (inner). Between these two layers is pleural fluid which hold the lungs against inner of chest wall. In lungs, smallest bronchioles open into clusters of tiny air sacs called alveoli.