Section 1

Question 1

In addition to external respiration, the respiratory system plays many other key roles in the body. Provide some examples.

Answer 1

• Enables speech by air passing over the vocal chords.
• Defends against inhaled foreign matter.
• The respiratory muscles play a role in parturition and defecation.
• The lung acts as a blood reservoir to allow for rapid equalization of left and right cardiac outputs.
• Helps to maintain the acid-base balance

Question 2

What are the three anatomical parts of the respiratory system?

Answer 2

The lungs, the chest wall, and the pleural space.

Question 3

How are the lungs divided anatomically?

Answer 3

The lungs are split into the upper and lower tract.

Question 4

What are the two main components of the respiratory system?

Answer 4

The airways and the alveoli.

Question 5

What is the function of the airways in the respiratory system?

Answer 5

The airways carry air between the atmosphere and the alveoli, where oxygen and carbon dioxide are exchanged.

Question 6

What does the upper airway include?

Answer 6

The upper airway includes the nose, nasal cavities, pharynx, and the digestive system.

Question 7

What is the pharynx, and what is its role in the respiratory system?

Answer 7

The pharynx is the common tube for respiration, and from the pharynx, air travels to the larynx.

Question 8

Where does air travel after leaving the pharynx?

Answer 8

Air travels to the larynx, which is the location of the vocal cords.

Question 9

What marks the beginning of the lower airway in the respiratory system?

Answer 9

The lower airway begins with the trachea.

Question 10

What does the trachea divide into, and what is the role of each division?

Answer 10

The trachea divides into the left and right bronchi, each of which supplies a lung.

Question 11

What are the progressively narrower airways that branch from the bronchi?

Answer 11

The bronchi branch into progressively narrower airways known as bronchioles.

Question 12

What is the term for the smallest bronchioles, and why are they significant?

Answer 12

The smallest bronchioles are known as respiratory bronchioles, and their walls are so thin that some gas exchange can occur.

Question 13

Where does gas exchange primarily occur in the respiratory system?

Answer 13

At the end of the terminal bronchioles are the alveoli, which are the air sacs where the majority of gases are exchanged between air and blood.

Question 14

What is another term for the branching airways of the lower tract?

Answer 14

The branching airways of the lower tract are often described as the respiratory tree or tracheobronchial tree.

Question 15

At which point in the airways does the flow transition from convective to diffusive?

Answer 15

The flow transitions from convective to diffusive at the level of the respiratory bronchioles.

Question 16

How is the branching of the airways similar to the circulatory system?

Answer 16

Similar to the circulatory system, even though each branch gets smaller, the overall cross-sectional area increases.

Question 17

Why is the increase in cross-sectional area of the branching airways important?

Answer 17

It is important because it allows for the transition from convective flow, which requires energy for air flow maintenance, to diffusive flow, which occurs passively and allows air to flow into the alveoli.

Question 18

Where does the diffusive zone begin in the respiratory system?

Answer 18

The diffusive zone begins at the level of the respiratory bronchioles.

Question 19

What does the chest wall include in the context of respiration?

Answer 19

The chest wall includes the thorax (chest) and the abdomen.

Question 20

What does the thoracic cavity contain, and what protects it?

Answer 20

The thoracic cavity contains the lungs and the heart and is protected by the rib cage.

Question 21

What muscles are found between the ribs in the chest wall?

Answer 21

The intercostal muscles are found between the ribs in the chest wall, and they are divided into the inner intercostal muscles and the external intercostal muscles.

Question 22

What separates the thoracic cavity and abdominal cavity in the chest wall?

Answer 22

The thoracic cavity and abdominal cavity are separated by the diaphragm, a large sheet of skeletal muscle.

Question 23

What are the main inspiratory muscles, and what do they do during inspiration?

Answer 23

The main inspiratory muscles are the diaphragm and the external intercostal muscles. During inspiration, the diaphragm descends to enlarge the thoracic cavity, and the external intercostal muscles elevate the ribs to further enlarge the thoracic cavity.

Question 24

Which muscles are responsible for decreasing the volume of the thoracic cavity during expiration?

Answer 24

The main expiratory muscles are the internal intercostal muscles and the abdominal muscles.

Question 25

In what situations are the expiratory muscles generally recruited in healthy individuals?

Answer 25

The expiratory muscles are generally inactive in healthy individuals and are recruited only during an increase in ventilator demand, such as during exercise or activities like coughing, sneezing, and vomiting.

Question 26

What is the third important anatomical feature in addition to the lungs and chest wall in the respiratory system?

Answer 26

The third important anatomical feature is the pleural space.

Question 27

What covers the lung, and what lines the inside wall of the thorax?

Answer 27

The lung is covered by the visceral pleura, and the inside wall of the thorax is lined by the parietal pleura.

Question 28

What is found between the visceral pleura and the parietal pleura?

Answer 28

The pleural space

Question 29

How thick is the pleural space, and what is found within it?

Answer 29

The pleural space is relatively small (around 2 mm) and is filled with fluid, known as pleural fluid.

Question 30

What is the function of the pleural fluid in the pleural space?

Answer 30

The pleural fluid allows the visceral and parietal pleurae to rub against each other during breathing with reduced friction.

Question 31

What is the main goal of external respiration?

Answer 31

The main goal of external respiration is to move oxygen-containing air into the alveoli, allowing oxygen to be transported to the tissues by the circulatory system, and to remove carbon dioxide from the alveoli.

Question 32

What are the two processes involved in external respiration?

Answer 32

The two processes involved in external respiration are:

1. The ability of respiratory muscles to generate the necessary pressure gradient to move air through the airways and inflate the lungs.
2. The ability of oxygen and carbon dioxide to diffuse across the alveolar-capillary barrier.

Question 33

What is the primary function of the respiratory muscles in respiration?

Answer 33

The primary function of the respiratory muscles is to generate the necessary pressure gradient to move air through the airways and inflate the lungs, overcoming the resistance to flow.

Question 34

What allows oxygen and carbon dioxide to move across the alveolar-capillary barrier?

Answer 34

The ability of oxygen and carbon dioxide to diffuse across the alveolar-capillary barrier allows them to move between the alveoli and the circulatory system.

Question 35

How can the processes involved in respiration be expressed mathematically? (flow)

Answer 35

Both processes can be explained by the equation: Pressure / Resistance = Flow (or diffusion).

Question 36

Which of the following muscles play a role in inspiration?

a) External intercostals, pectoralis, diaphragm

b) External intercostals, internal intercostals, diaphragm

c) Internal intercostals, diaphragm

d) External intercostals, diaphragm

Answer 36

d)

Question 37

Which of the following muscles play a role in expiration?

a) External intercostals, diaphragm

b) Pectoralis muscle, diaphragm, latissimus dorsi

c) Internal intercostals, internal obliques

d) Internal intercostals, internal obliques, diaphragm

Answer 37

d)