Lesson 5 (Chapter 2: Structures of the Respiratory System)

Question 1

Nasal Cavity

Answer 1

Air enters the nasal cavity through two openings called the nares, or nostrils. The nasal cavity is lined with a mucous membrane. The mucus that lines the mucous membrane provides a physical barrier against invasion by pathogens (harmful microorganisms), dust, and pollen. It is sticky and traps these particles when they enter the nasal cavity. In addition, inhaled air is warmed and moistened by the tissue that lines the nasal cavity.

Question 2

Olfactory Receptors

Answer 2

Humans have 12 million receptor cells for smell in the extreme upper region of the nasal cavity (olfactory region). By contrast, dogs have 4 billion receptor cells, which is why they can be trained to sniff for drugs, explosives, and dead bodies.

Question 3

Paranasal Sinuses

Answer 3

Paranasal sinuses are air-filled cavities that surround the nasal cavity. They reduce the skull’s weight, produce mucus, and influence voice quality by acting as resonating chambers. The four paranasal sinuses are maxillary, ethmoid, sphenoid, and frontal.

Question 4

Pharynx

Answer 4

Commonly known as the throat, the pharynx is a passageway that serves both the respiratory and digestive systems. The pharynx receives air after it passes through the nose or mouth.

Question 5

Larynx

Answer 5

Commonly known as the voice box, the larynx lies between the pharynx and the trachea. Air exhaled from the lungs passes through the larynx and vibrates the vocal folds to create sound.

Question 6

Trachea

Answer 6

Commonly known as the windpipe, the trachea is the main airway to the lungs. The trachea divides into two large branches (primary bronchi), which channel air to the right or left lung.

Question 7

Lunga

Answer 7

Two lungs expand and contract to supply oxygen to tissues all over the body and dispose of carbon dioxide. A double-layered serous membrane called the pleura encloses each lung. This membrane also divides each lung into sections called lobes. The right lung has three lobes. The left lung has two lobes to make room for the heart.

Question 8

Bronchi and Bronchioles

Answer 8

The bronchi and bronchioles are a network of intricate passages that supply the lungs with air. The primary bronchi run into each lung before branching off into smaller bronchi. These smaller bronchi subdivide into increasingly smaller branches called bronchioles. Each bronchiole further splits into many smaller branches called terminal bronchioles. Finally, the millions of tiny terminal bronchioles conduct air to the alveoli of the lungs.

Question 9

Alveoli

Answer 9

Alveoli (air sacs) are very small, grapelike clusters at each bronchiole’s end. Exchange of oxygen and carbon dioxide between the air in the lungs and the blood in the capillaries occurs across the walls of the millions of alveoli in each lung.

Question 10

Diaphragm

Answer 10

The diaphragm is a muscular sheet between the base of the lungs and the abdominal cavity. The contraction and relaxation of this muscle makes breathing possible.

Question 11

Py/o

Answer 11

Pus

Question 12

Melan/o

Answer 12

Black

Question 13

Myc/o

Answer 13

Fungus

Question 14

Hem/o

Answer 14

Blood

Question 15

Bronch/o, Bronch/i

Answer 15

Brouchus

Question 16

Thorac/o, Thor/a

Answer 16

Chest or chest cavity

Question 17

-centesis

Answer 17

Surgical puncture for the removal of fluid

Question 18

-pnea

Answer 18

Breathing

Question 19

-ptysis

Answer 19

coughing or spitting

Question 20

-rhea

Answer 20

flow or discharge

Question 21

-rrhagia

Answer 21

bleeding or hemorrhage

Question 22

-scopy

Answer 22

Process of viewing or examining with a lighted instrument called a scope

Question 23

-phonia

Answer 23

Voice or sound

Question 24

-osis

Answer 24

Abnormal condition

Question 25

Dys-

Answer 25

Abnormal, painful, labored or defective

Question 26

A-, An-

Answer 26

Without, absence of or lack of