3 - Bronchi, pleura, lungs and diaphragm

Question 1

What verterbra is the most prominent in the neck?

Answer 1

C7

Question 2

What is the asymmetry in the primary bronchi?

Answer 2

the right is wider and more vertical than the left

Question 3

What is the larynx important in surgery?

Answer 3

a site of possible airway opening in emergencies/blockage (cricothyroidotomy)

Question 4

The lungs lie free in the pleural cavity except ____

Answer 4

the hilum/ lung root

the attachment to the heart and trachea

Question 5

In a cadaver, how could you tell the differences between the vessels and the airways for the lung?

Answer 5

airways are striped (since they are cartilaginous)and vessels are smooth

Question 6

What are the 3 surfaces of the lung and what are they on contact with?

Answer 6

costal, medial and inferior
costal - (the entire outer surface) in contact with the ribcage
medial - mediastinal - in contact with the mediastinum and the heart
inferior - diaphragmatic - in contact with the diaphragm

Question 7

How can you differentiate between the hilum of the right and the left lung?

Answer 7

the way the groove of the aorta is around the hilum

Question 8

What are the 2 fissures of the right lung and which lobes do they separate?

Answer 8

oblique fissure - separates the inferior lobe from the other two
horizontal fissure - separates the superior from the middle lobe

Question 9

Why do the two layers of the pleura remain attached?

How do they slides against each other to allow movement of the lung during ventilation?

Answer 9

they have surface tension

the pleural fluid allows frictionless sliding during ventilation

Question 10

What is the pleura?

Answer 10

a thin layer of flattened cells supported by connective tissue that lines each pleural cavity and converts the exterior of the lungs

Question 11

What are the 2 layers the pleura and what surfaces do they line?

Answer 11

• visceral - covers the surface lung and lines the fissures between the lobes
• parietal - liners the inner surface of chest walls

Question 12

What is the arrangement of the pleura in a healthy person?

Answer 12

it is collapsed

but moist surfaces allow the lungs to glide as they expand and collapse

Question 13

What is the origin of the pleura?

Answer 13

the pleural cavities are within the chest wall

the lung bud grows into them

Question 14

Where is the costodiaphragmatic recess?

Answer 14

it is at the base, where the pleural cavity is not filled with lung (except in maximal inspiration)
it is a sight of potential fluid retention

Question 15

How do the landmarks differ between the lung and the pleura?

Answer 15

superiorly - the lungs follow the extent of the pleural cavity
inferiorly - the pleural cavity extends beyond/below the base of the lung (except in deep inspiration)

Question 16

Which vertebral nerve do the nerves supplying the diaphragm come from?

Answer 16

C3,4,5 (phrenic nerves)

Question 17

Explain why the diaphragm is the main inspiratory muscle

Answer 17

• contraction increases the vertical dimensions of the thoracic cavity
• during contraction, the diaphragm presses on the abdominal viscera which initially descend
• further descent is stopped by the abdominal viscera, so the costal margin then moves upwards

Question 18

At what vertebral level do the IVC, oesophagus and the aorta pass though the diaphragm?

Answer 18

I - 8
O - 10
A - 12

Question 19

What 4 things does the diaphragm attach to?

Answer 19

capital margin
xiphoid process
ends of ribs 11 and 12
lumbar vertebrae

Question 20

What happens to the ribs during inhalation?

Answer 20

• the ribs are elevated
  (then anterior end trusts forwards and upwards)
• the ribs are everted
  (increasing transverse dieter of thoracic cavity)
• internal and external intercostal muscles stiffen the ribcage to increase efficiency of diaphragm

Question 21

What is expiration reliant on?

Answer 21

elastic recoil in the elastic tissue of the lung and ribcage

Question 22

What is the action in forced expiration?

Answer 22

the muscles of the abdominal walls squeeze the abdominal organs against the diaphragm and pull the lower ribs downwards