Ch1

Question 1

What are the main functions of the respiratory system?

Answer 1

The main functions are:
* Obtain oxygen from the external environment
* Supply oxygen to the cells
* Remove carbon dioxide produced by cellular metabolism

Question 2

What components make up the respiratory system?

Answer 2

The respiratory system is composed of:
* Lungs
* Conducting airways
* Parts of the central nervous system controlling respiration
* Chest wall

Question 3

What muscles are included in the chest wall for respiration?

Answer 3

The chest wall includes:
* Diaphragm
* Intercostal muscles
* Abdominal muscles
* Rib cage

Question 4

What is the role of the respiratory system in acid-base balance?

Answer 4

The respiratory system participates in acid-base balance by removing CO2 from the body, affecting hydrogen ion concentration.

Question 5

What is gas exchange in the respiratory system?

Answer 5

Gas exchange involves:
* Oxygen from ambient air exchanged for carbon dioxide in alveoli
* Fresh air inspired into lungs
* Venous blood with high CO2 content pumped into lungs

Question 6

What happens to blood after gas exchange in the lungs?

Answer 6

Blood leaving the lungs has a high oxygen content and a relatively low carbon dioxide content, distributed to tissues by the left side of the heart.

Question 7

True or False: The conducting zone of the airways contains alveoli.

Answer 7

False

Question 8

At which airway generations do alveoli start to appear?

Answer 8

Alveoli start to appear at the 17th through the 19th generations.

Question 9

What is the anatomic dead space in the respiratory system?

Answer 9

The anatomic dead space consists of the first 16 generations of airways, which contain no alveoli and are incapable of gas exchange.

Question 10

What is the alveolar-capillary unit?

Answer 10

The alveolar-capillary unit is the site of gas exchange in the lung, comprising alveoli enveloped in pulmonary capillaries.

Question 11

How many alveoli are estimated to be in an adult human lung?

Answer 11

Approximately 300 million, with some estimates suggesting up to 480 million.

Question 12

What type of cells line the airways of the respiratory system?

Answer 12

The airways are lined with:
* Ciliated cells
* Mucus-secreting goblet cells
* Club cells

Question 13

What is the function of Club cells in the bronchioles?

Answer 13

Club cells secrete proteins, lipids, glycoproteins, and modulators of inflammation; they also act as progenitor cells.

Question 14

What are the primary characteristics of the trachea?

Answer 14

The trachea is a fibromuscular tube supported by C-shaped cartilage and completed by smooth muscle.

Question 15

What happens to the cartilage structure as bronchi enter the lungs?

Answer 15

The cartilage rings disappear and are replaced by irregularly shaped cartilage plates.

Question 16

What is the role of mast cells in the airways?

Answer 16

Mast cells contain inflammatory mediators that can induce bronchoconstriction, stimulate mucus secretion, and increase permeability of bronchial vessels.

Question 17

Fill in the blank: The alveolar surface is mainly composed of _______ cells.

Answer 17

squamous epithelial

Question 18

What are the two types of alveolar cells?

Answer 18

The two types of alveolar cells are:
* Type I alveolar cells
* Type II alveolar cells

Question 19

What is the main composition of the alveolar surface?

Answer 19

A thin layer of squamous epithelial cells (type I alveolar cells) and cuboidal type II alveolar cells

Type II cells produce the fluid layer that lines the alveoli.

Question 20

What is the primary function of type I alveolar cells?

Answer 20

Allow gas exchange between the alveolar air and the pulmonary capillary blood

They also help remove liquid from the alveolar surface.

Question 21

How do type II alveolar cells compare in number to type I cells?

Answer 21

There are about twice as many type II cells as type I cells in the human lung

Type I cells cover 90% to 95% of the alveolar surface due to their larger surface area.

Question 22

What role do alveolar macrophages play?

Answer 22

They patrol the alveolar surface and phagocytize inspired particles such as bacteria.

Question 23

What forms the pulmonary capillaries?

Answer 23

A single layer of squamous epithelial cells aligned to form tubes.

Question 24

What is the thickness of the barrier to gas exchange in the lungs?

Answer 24

0.2 to 0.5 mm thick.

Question 25

What are the primary components of the chest wall?

Answer 25

Rib cage, external and internal intercostal muscles, diaphragm, visceral and parietal pleura

Other muscles include abdominal muscles, rectus abdominis, parasternal intercartilaginous muscles, sternocleidomastoid, and scalene muscles.

Question 26

What initiates each breath in the respiratory system?

Answer 26

Groups of neurons located in the medulla.

Question 27

True or False: The muscles of respiration contract spontaneously.

Answer 27

False.

Question 28

What is one of the main functions of the respiratory system?

Answer 28

The exchange of oxygen from the atmosphere for carbon dioxide produced by the cells of the body.

Question 29

List other functions of the respiratory system.

Answer 29

• Participation in acid-base balance of the body
• Phonation
• Pulmonary defense
• Metabolism

Question 30

What is the role of the interstitial space in gas exchange?

Answer 30

It is the space between the alveolar epithelium and capillary endothelium that gases must pass through.

Question 31

Fill in the blank: The alveolar surface fluid layer is discussed in Chapter _______.

Answer 31

2.

Question 32

Fill in the blank: The control of breathing is discussed in Chapter _______.

Answer 32

9.

Question 33

What does the central nervous system contribute to the respiratory system?

Answer 33

It initiates breathing and integrates various influences on respiratory function.

Question 34

What is the diffusion pathway for gas exchange?

Answer 34

Alveolar epithelium, plasma, erythrocyte

These components create the barrier to gas exchange.