Exploring the Respiratory System

Which of the following is the main organ where gas exchange takes place in the human respiratory system?

• Heart

• Lungs

• Liver

• Kidneys

Identify the parts of the respiratory system shown in the image.

a

b

c

d

e

f

g

h

Trachea

Intestine

Stomach

Nasal cavity

Alveoli

Larynx

Diaphragm

Lungs

Pharynx

Bronchi

Which structure prevents food from entering the windpipe when you swallow?

(a)  

• Diaphragm

• Epiglottis
• Alveoli

• Larynx

What tiny air sacs in the lungs are responsible for the exchange of oxygen and carbon dioxide?

• Bronchi

• Alveoli

• Trachea

• Capillaries

Which gas is taken into the body during inhalation?

What is the main function of the diaphragm in breathing?

• To filter dust from the air

• To pump blood

• To help move air in and out of the lungs

• To produce sound

During gas exchange, which gas moves from the blood into the alveoli to be exhaled?

Which part of the respiratory system connects the throat (pharynx) to the lungs?

• Esophagus

• Trachea

• Diaphragm

• Stomach

What happens to oxygen after it enters the alveoli?

• It is exhaled immediately

• It dissolves in mucus

• It passes into the blood through capillaries

• It turns into carbon dioxide

Which of the following best describes the process of gas exchange in the lungs?

• Oxygen moves from the blood into the alveoli, and carbon dioxide moves from the alveoli into the blood

• Oxygen moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli

• Both oxygen and carbon dioxide move from the blood into the alveoli

• Both oxygen and carbon dioxide move from the alveoli into the blood