Respiratory System 2: Anatomy of breathing

Question 1

What regulates respiration?

Answer 1

Movements of the thoracic wall and the diaphragm.

Question 2

What happens during resting inspiration (quiet breathing)?

Answer 2

The diaphragm contracts, causing it to flatten.

Question 3

What occurs during forced inspiration?

Answer 3

The diaphragm contracts, and the thoracic wall expands.

Question 4

What happens to intrathoracic volume during inspiration?

Answer 4

It increases in the vertical, transverse, and anteroposterior dimensions.

Question 5

What happens to intrathoracic pressure during inspiration?

Answer 5

It decreases, drawing air into the lungs.

Question 6

What happens to the diaphragm during expiration?

Answer 6

It relaxes and moves superiorly.

Question 7

How does intrathoracic volume and pressure change during expiration?

Answer 7

Intrathoracic volume decreases, and pressure increases, expelling air.

Question 8

difference between bucket handle and pump handle

Answer 8

It describes the lateral movement of the ribs, increasing the transverse diameter of the thoracic cavity during inspiration.

It describes the anterior movement of the sternum, increasing the anteroposterior diameter of the thoracic cavity during inspiration.

Question 9

What is the usual diaphragm excursion during quiet breathing?

Answer 9

1.5 cm.

Question 10

How far can the diaphragm move during deep ventilation?

Answer 10

6 to 10 cm.

Question 11

What factors affect the level of the diaphragm?

Answer 11

Depth and phase of ventilation, as well as posture.

Question 12

When does the diaphragm perform the greatest ventilatory excursions?

Answer 12

When the body is in a supine position.

Question 13

What happens to the diaphragm’s position when the body is in an erect posture?

Answer 13

It becomes lower, decreasing the movement required for breathing.

Question 14

Which dome of the diaphragm is higher, and why?

Answer 14

The right dome is higher because of the liver’s position beneath it.

Question 15

How does posture affect the diaphragm during normal breathing?

Answer 15

In a supine position, the diaphragm performs greater excursions; in an erect posture, movement decreases.

Question 16

Which nerves supply the right and left domes of the diaphragm?

Answer 16

The right and left phrenic nerves.

Question 17

What happens if there is an injury to one phrenic nerve?

Answer 17

Only the ipsilateral (same side) dome of the diaphragm is affected.

Question 18

What are the symptoms of unilateral diaphragm paralysis?

Answer 18

It is often asymptomatic.

Question 19

What are the consequences of bilateral diaphragm paralysis?

Answer 19

It usually leads to respiratory distress, and the role of accessory respiratory muscles becomes significant.

Question 20

How does paralyzed inspiration appear compared to normal inspiration?

Answer 20

The affected dome does not contract and remains elevated during inspiration.

Question 21

Why does the paralyzed dome remain elevated during inspiration?

Answer 21

The paralyzed dome cannot contract due to nerve injury.

Question 22

What compensates for diaphragm dysfunction in cases of bilateral paralysis?

Answer 22

Accessory respiratory muscles.

Question 23

What allows the downward movement of the diaphragm during respiration?

Answer 23

The extensibility of the abdominal wall, which allows the abdominal viscera to be compressed and displaced.

Question 24

Which muscles are important for forced expiration (e.g., during coughing)?

Answer 24

The anterior wall abdominal muscles, including the external oblique, internal oblique, rectus abdominis, and transversus abdominis

Question 25

What is the role of the external oblique (EO) and rectus abdominis (RA) during forced expiration?

Answer 25

They pull the ribcage inferiorly by contracting and attaching to the hip bone.

Question 26

What is the function of the transversus abdominis (TA) in respiration?

Answer 26

It compresses the abdominal cavity and assists with the elevation of the diaphragm.

Question 27

What structure is shown connecting the abdominal muscles to enhance their function?

Answer 27

The aponeurosis.

Question 28

What is the role of neck muscles in respiration?

Answer 28

Neck muscles attaching to the thoracic inlet hold up the ribcage, acting against gravity to prevent the chest wall from being depressed.

Question 29

What are the main neck muscles involved in respiration?

Answer 29

Scalene muscles Sternocleidomastoid muscle

Question 30

Why do runners bend over to grab their knees after intense exercise?

Answer 30

To use accessory muscles of respiration, such as the pectoral muscles, to maximize breathing by stabilizing the upper limbs.

Question 31

What is the primary action of the pectoral muscles during accessory respiration?

Answer 31

They elevate the ribcage to assist in breathing.

Question 32

What happens when the upper limbs are stabilized by holding the knees?

Answer 32

The pectoral muscles can function as accessory respiratory muscles instead of performing their primary actions related to limb movement.

Question 33

How does bending over reduce the effect of gravity on the chest wall?

Answer 33

It minimizes the gravitational pull that tends to depress the chest wall, aiding respiration.

Question 34

What are the two pectoral muscles involved in accessory respiration?

Answer 34

Pectoralis major Pectoralis minor

Question 35

What is the primary role of external intercostal muscles?

Answer 35

They are active during inspiration and help elevate the ribs.

Question 36

What function do all intercostal muscles share?

Answer 36

They keep intercostal spaces rigid, preventing them from collapsing or bulging during respiration.

Question 37

What are the 2 debated roles of internal and innermost intercostal muscles?

Answer 37

They may elevate the ribs during inspiration. They may depress the ribs.

Question 38

How are the interosseous internal intercostal muscles classified functionally?

Answer 38

They are expiratory.

Question 39

How are the interchondral internal intercostal muscles classified functionally?

Answer 39

They are inspiratory, based on experimental evidence from electrical activity recordings.

Question 40

What happens to the ribs during inspiration with the help of external intercostal muscles?

Answer 40

The ribs are elevated.

Question 41

What happens to the ribs during expiration with the help of internal intercostal muscles?

Answer 41

The ribs are depressed.

Question 42

Where does the trachea begin and end?

Answer 42

It begins inferior to the larynx and ends at the tracheal bifurcation.

Question 43

What is the structure of the trachea?

Answer 43

It consists of C-rings of tracheal (hyaline) cartilage, closed posteriorly by connective tissues and smooth (trachealis) muscle.

Question 44

What are the main divisions of the bronchi from the trachea?

Answer 44

Left and right main bronchi Lobar bronchi (two on the left, three on the right) Segmental bronchi

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Question 58

How does the right bronchus differ from the left?

Answer 58

The right main bronchus has three lobar bronchi, while the left has two.

Question 59

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Question 60

How are the lobes of the lungs further subdivided?

Answer 60

Into bronchopulmonary segments.

Question 61

how many lobes does the right lung have?

Answer 61

Three lobes: superior, middle, and inferior.

Question 62

How many lobes does the left lung have?

Answer 62

Two lobes: superior and inferior.

Question 63

What is a bronchopulmonary segment?

Answer 63

A subdivision of a lobe, each receiving a segmental bronchus and a segmental artery.

Question 64

What are the 3 segments in the superior lobe of the right lung?

Answer 64

Segment I Segment II Segment III

Question 65

What are the 2 segments in the middle lobe of the right lung?

Answer 65

Segment IV Segment V

Question 66

What are the 5 segments in the inferior lobe of the right lung?

Answer 66

Segment VI Segment VII Segment VIII Segment IX Segment X

Question 67

What is unique about the left lung's superior lobe?

Answer 67

It includes the lingula, which corresponds to segments IV and V.

Question 68

What 4 segments are found in the inferior lobe of the left lung?

Answer 68

Segment VI Segments VII + VIII (combined) Segment IX Segment X

Question 69

How many bronchopulmonary segments does each lung have?

Answer 69

Ten segments.

Question 70

What defines the boundaries of bronchopulmonary segments?

Answer 70

The branching pattern of the segmental bronchi.

Question 71

Are the segmental boundaries visible on the lung surface?

Answer 71

No, the segmental boundaries are not visible on the lung surface.

Question 72

Why is knowledge of bronchopulmonary segments important in surgery?

Answer 72

Tumors or abscesses often localize in a specific bronchopulmonary segment, which can be surgically resected.

Question 73

What is a segmentectomy?

Answer 73

The surgical removal of a single bronchopulmonary segment.

Question 74

What is a lobectomy?

Answer 74

The surgical removal of an entire lobe of the lung.

Question 75

What is a pneumonectomy?

Answer 75

The surgical removal of an entire lung.

Question 76

How does the right main bronchus differ from the left?

Answer 76

The right main bronchus is more vertical and wider than the left, making it easier to view with an endoscope.

Question 77

What is the carina?

Answer 77

A ridge of cartilage on the inner surface of the tracheal bifurcation, serving as an important landmark during bronchoscopy.

Question 78

Where is the carina located?

Answer 78

Slightly to the left of the median plane of the trachea.

Question 79

Why do foreign bodies often enter the right main bronchus?

Answer 79

Because it is more vertical and wider than the left main bronchus.

Question 80

What is the tracheal bifurcation?

Answer 80

The point where the trachea divides into the left and right main bronchi.

Question 81

What is the significance of the carina in medical procedures?

Answer 81

It is used as a landmark during bronchoscopy to navigate the airway anatomy.

Question 82

What are the two principal parts of the bronchial tree?

Answer 82

Conducting part (blue) Respiratory part (pink)

Question 83

How does the amount of cartilage change along the bronchial tree?

Answer 83

It decreases toward the distal end and disappears completely at the level of the bronchiole.

Question 84

What distinguishes a conducting bronchiole from a respiratory bronchiole?

Answer 84

Conducting bronchioles lack glands and alveoli, while respiratory bronchioles have alveoli.

Question 85

What is the final conducting segment of the bronchial tree called?

Answer 85

Terminal bronchiole.

Question 86

What structures are part of the respiratory portion of the bronchial tree?

Answer 86

Respiratory bronchioles Alveolar ducts Alveolar sacs with alveoli

Question 87

Where do pulmonary alveoli begin to appear?

Answer 87

As extensions from the lumens of respiratory bronchioles.

Question 88

What is the basic structural unit of gas exchange in the lungs?

Answer 88

Pulmonary alveoli.

Question 89

How many alveolar ducts does each respiratory bronchiole give rise to?

Answer 89

2–11 alveolar ducts.

Question 90

What do alveolar ducts lead to?

Answer 90

5–6 alveolar sacs where clusters of alveoli open.

Question 91

What type of epithelium composes the alveolar walls?

Answer 91

Thin simple squamous epithelium.

Question 92

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