Respiratory System

Question 1

What is respiration?

Answer 1

Respiration is the sequence of events that result in the exchange of oxygen and carbon dioxide between the atmosphere and cells of our body.

Question 2

Role of the nose:

Answer 2

The function of the nasal cavity is to warm, humidify, and filter air entering body. Cilia help trap particles and are a first line of defence. Mucus is then secreted to trap substances from inhaled air.

Question 3

Role of the mouth:

Answer 3

Mouth can be used to replace nasal cavity’s functions when needed but doesn’t warm and moisturise air entering lungs as well as nose, due to shorter distance. It lacks hairs and mucus which means foreign particles could enter the respiratory system.

Question 4

Role of the pharynx:

Answer 4

Receives air from nasal cavity which is diverted to larynx by the epiglottis. Epiglottis ensures air passes into trachea by covering oesophagus.

Question 5

Role of the larynx:

Answer 5

Helps to direct air and food into proper channels and is inferior to pharynx. Larynx also has role in speech, as vocal cords close and vibrate as air is exhaled. Air passes between cords to produce sound.

Question 6

Role of the trachea:

Answer 6

The only pathway to the lungs which provides a passageway for air. Trachea is also lined with mucus and cilia to trap airborne particles. Inferior end of it branches into left and right bronchi.

Question 7

Role of the bronchi and bronchioles:

Answer 7

Trachea is divided into left and right bronchi. Bronchi branches into smaller passageways called bronchioles, which then lead to tiny air sacs of the alveoli.

Question 8

Role of the lungs:

Answer 8

Main function of lungs is to perform exchange of oxygen and carbon dioxide with air we breathe from atmosphere. Lungs contain pleura, which produces pleural fluid and creates cavities that separate lungs from other organs. Also plays role in lungs expanding during inspiration, allowing lungs to fill with air.

Question 9

Difference between right and left lungs:

Answer 9

Left lung contains cardiac notch, where heart sits between lungs and has two lobes. Right lung has three lobes and is bigger.

Question 10

External respiration:

Answer 10

oxygen diffuses from alveolar air into blood, carbon dioxide diffuses out from blood into alveolar air.

Question 11

Internal respiration

Answer 11

oxygen diffuses out from blood to tissues, carbon dioxide diffuses into blood from tissue.

Question 12

Inspiration:

Answer 12

taking air into lungs. Result of muscle contraction. Diaphragm contracts and thoracic cavity increases in volume.

Question 13

Expiration:

Answer 13

letting air out of lungs. Relaxation of diaphragm and recoil of tissue decreases thoracic cavity volume.

Question 14

Function of respiratory system:

Answer 14

responsible for respiration and gaseous exchange between blood and external environment.

Question 15

Structure:

Answer 15

Three major parts are lungs, airway, and muscles of ventilation.