Respiratory System

Question 1

Respiration

Answer 1

Respiration is the life-sustaining process in which gases are exchanged between the body and the outside atmosphere.

Question 2

Ventilation

Answer 2

Respiration by the respiratory system actually involves two subsidiary processes. One process is ventilation, or breathing. Ventilation is the physical process of conducting air to and from the lungs.

Question 3

Gas Exchange

Answer 3

The other process is gas exchange. This is the biochemical process in which oxygen diffuses out of the air and into the blood, while carbon dioxide and other waste gases diffuse out of the blood and into the air.

Question 4

Nasal Cavity

Answer 4

The nasal cavity is a large, air-filled space in the skull above and behind the nose in the middle of the face. It is a continuation of the two nostrils. It is a continuation of the two nostrils.

Question 5

Pharynx

Answer 5

The pharynx is a tube-like structure that connects the nasal cavity and the back of the mouth to other structures lower in the throat, including the larynx. The pharynx has dual functions — both air and food (or other swallowed substances) pass through it, so it is part of both the respiratory and the digestive systems.

Question 6

Larynx

Answer 6

The larynx connects the pharynx and trachea, and helps to conduct air through the respiratory tract. The larynx is also called the voice box, because it contains the vocal cords, which vibrate when air flows over them, thereby producing sound.

Question 7

Trachea

Answer 7

The trachea, or windpipe, is the widest passageway in the respiratory tract. It is about 2.5 cm (1 in.) wide and 10-15 cm (4-6 in.) long. It is formed by rings of cartilage, which make it relatively strong and resilient. The trachea connects the larynx to the lungs for the passage of air through the respiratory tract. The trachea branches at the bottom to form two bronchial tubes.

Question 8

Bronchi and Bronchioles

Answer 8

There are two main bronchial tubes, or bronchi (singular, bronchus), called the right and left bronchi. The bronchi carry air between the trachea and lungs. Each bronchus branches into smaller, secondary bronchi; and secondary bronchi branch into still smaller tertiary bronchi. The smallest bronchi branch into very small tubules called bronchioles. The tiniest bronchioles end in alveolar ducts, which terminate in clusters of minuscule air sacs, called alveoli (singular, alveolus), in the lungs.

Question 9

Lungs

Answer 9

The lungs are the largest organs of the respiratory tract. They are suspended within the pleural cavity of the thorax.

Question 10

Pleura

Answer 10

The lungs are surrounded by two thin membranes called pleura, which secrete fluid that allows the lungs to move freely within the pleural cavity. This is necessary so the lungs can expand and contract during breathing.

Question 11

Alveoli

Answer 11

Lung tissue consists mainly of alveoli. These tiny air sacs are the functional units of the lungs where gas exchange takes place.

Question 12

Mucociliary Escalator

Answer 12

The main way the respiratory system protects itself is called the mucociliary escalator. From the nose through the bronchi, the respiratory tract is covered in epithelium that contains mucus-secreting goblet cells. The mucus traps particles and pathogens in the incoming air.

Question 13

Cilia

Answer 13

The epithelium of the respiratory tract is also covered with tiny cell projections called cilia (singular, cilium). The cilia constantly move in a sweeping motion upward toward the throat, moving the mucus and trapped particles and pathogens away from the lungs and toward the outside of the body.

Question 14

Diaphragm