The respiratory tree and lungs

Question 1

where are the c shaped rings of cartilage deficient

Answer 1

deficient posteriorly where the trachea is adjacent to the oesophagus

Question 2

what does the flexibility of the trachea allow

Answer 2

• it allows the upper end to move with the pharynx

Question 3

what happens ti the lower level of the trachea

Answer 3

ower end moves with the diaphragm as it is lowered and raised in respiration.

Question 4

what are on either side of the trachea

Answer 4

• the common carotid arteries

Question 5

what lies in front of the trachea

Answer 5

• the thyroid gland at the level of C5-T1

Question 6

what is the difference between the right and left bronchus

Answer 6

the right main bronchus is wider and shorter (2.5cm) than the left (5cm) and passes directly to the hilum of the lung.
Because it is wider and more vertical than the left main bronchus, foreign objects inhaled by small children lodge more frequently in the right main bronchus than the left.

Question 7

describe the structure of the bronchi

Answer 7

• within the lung the main bronchi divides into lobar bronchi they each supply one lobe of a lung with air
• the left lung has two lobes white the right lung has three so there are two lobar bronchi on the left and 3 on the right
• Each lobar bronchus divides into several segmental bronchi each going to one bronchopulmonary segment
• These airways then subdivide many times, the branches becoming smaller on each division. The smallest branches are called bronchioles.

Question 8

describe the structure of the bronchioles

Answer 8

These do not have any cartilage in their walls but do have large amounts of smooth muscle so that these airways, by constricting or relaxing, control the flow of air into the air sacs or alveoli, where gaseous exchange takes place.

Question 9

what does each lung have

Answer 9

a base, an apex, costal and medial surfaces and a hilum

Question 10

what is the hilum of the lung

Answer 10

the area on the medial surface where vessels, nerves and bronchi enter and leave the lung

Question 11

the right lung is …

Answer 11

shorter than the left as the right dome of the diaphragm is higher than the left
- the right lung is also wider as the heart and pericardium bulge more to the left

Question 12

how do you distinguish the left lung from the right lung

Answer 12

by the large cardiac notch

Question 13

what are the bronchopulmonary segments

Answer 13

The bronchopulmonary segments are pyramidal shaped segments of lung with the apex of the segment at the lung root and its base on the surface.
- each bronchopulmonary segment is supplied by a segmental bronchus and a segmental branch of the pulmonary artery

Question 14

what are the bronchopulmonary segments separated by

Answer 14

segemetnated by a connective tissue septa

Question 15

what do the bronchial veins drain into

Answer 15

azygos and hemiazygos veins

- also communicate with the pulmonary veins

Question 16

how do the alveoli receive blood

Answer 16

it receives deoxygenated blood from the terminal branches of the pulmonary arteries
- The oxygenated blood leaving the alveolar capillaries drain to the tributaries of the pulmonary vein, which follow intersegmental connective tissue septa to the lung root

Question 17

where do lymph vessels originate

Answer 17

• they originate in the superficial and deep plexuses, they are not present in alveolar walls

Question 18

where does the superficial plexus lie

Answer 18

The superficial plexus lies beneath the visceral pleura and drains over the surface of the lung to the lung hilum.

Question 19

where does the deep plexus travel

Answer 19

The deep plexus travels along the bronchi and pulmonary vessels toward the hilum of the lung, passing through pulmonary nodes located in the lung, and the lymph then enters the bronchopulmonary nodes which are concentrated around the lung hilum.

Question 20

where do the lymph go from the lungs

Answer 20

All the lymph from the lung leaves the hilum and drains into the tracheobronchial nodes and then into bronchomediastinal lymph trunks.