Introduction To The Respiratory System

Question 1

What are the types of breathing

Answer 1

Thoracic, uses the ribs

Diaphragmatic, uses the diaphragm

Question 2

How do you image the lungs

How do you image the airways

Answer 2

Normally PA, capture heart at its approximate size
If AP, heart can look enlarged as it is further away from the film

Can’t see airways unless patient breathes in contrast that covers airways (bronchogram)

Question 3

What structures can you see in an X-ray

Answer 3

Cloudiness, pulmonary artery and veins
White heart
Trachea, translucency in front of vertebra

Question 4

Differences between inspiration and expiration on images

Answer 4

Heart is longer and thinner during inspiration

• Bottom of heart attached to diaphragm, brought down with it
• Diaphragm is flatter

Heart is more rounded during expiration

• Diaphragm more rounded
• L hemidome contains gastric bubble

Question 5

Openings of the thoracic cavity

Answer 5

Superior thoracic aperture and inferior thoracic aperture

Question 6

Relations of the superior thoracic aperture

Answer 6

Costal cartilage
R1
Manubrium sternum
Vertebrae

Question 7

What passes through the thoracic inlet?

What covers the inlet

Answer 7

Enclosed space with pathway for oesophagus and vessels

Suprapleural membrane rises up to C6, seals aperture
Parietal pleura comes under membrane, lung comes up to the root of the neck

Question 8

Boundaries of the thoracic outlet

Answer 8

Inferior thoracic aperture surrounded by costal margin, floating rib tips, T12

Closed up by diaphragm

Question 9

What are the attachments of the diaphragm

Answer 9

R11-12

T12-L2

Question 10

What are the openings in the diaphragm

Answer 10

Caval opening for vena cava in central tendon
-R phrenic nerve

Oesophageal opening

• R and L vagus
• L gastric artery, vein

Aortic opening between 2 crus

• Thoracic duct
• Azygos

Question 11

Describe the levels of the hemidiaphragms and why

What are the nervous innervations of each hemidiaphragm

Answer 11

R hemidiaphragm, up to R4-4th ICS due to presence of liver
L hemidiaphragm, up to R5-5th ICS

L hemidiaphragm, L phrenic (motor)
R hemidiaphragm, R phrenic (motor)

Question 12

Describe in detail the vessels and tubes that leave and enter the thoracic inlet

Answer 12

Subclavian veins at the front, internal jugular comes vertically
Subclavian arteries at the back, common carotid comes vertically

Trachea in front of oesophagus, surrounded by pretracheal fascia

All vessels wrapped up in suprapleural fascia

Question 13

Describe the location of the phrenic angle and it’s uses

Answer 13

Found between 8-11th ICS, midaxillary

Lung tissue and visceral pleura don’t come down into recess
Parietal pleura comes down into recess

Pleural fluid accumulated in costodiaphragmatic recess, can tap into pleural fluid

Watch out of collateral nerve and NMB

Question 14

Mechanism of breathing in terms of pleural pressures

Answer 14

Inspiration, contraction and flattening of D, increased V, decreased P, air in

Expiration, relax and elevation of D, decreased V, increased P, air out

Chest wall held up by sternocleidomastoid and scalenes
Parietal pleura pulled upwards
Visceral pleura attached to lung which recoiled inwards due to elastin and collagen
When Ppl = more -ve than -3, forces lungs to recoil out, air in

Question 15

Describe the main mechanism needed for respiratory

Answer 15

Pleural cavity between parietal pleura = 10-20 ml of fluid
Resulting -ve hydrostatic pressure sticks pleura together
Allows the lungs to move

Question 16

How do the pleural membranes surround the lungs and lung hilum

What is the function of the lung hilum

Answer 16

Visceral pleura lines lungs and fissures
Parietal pleura folds into hilum and becomes visceral, forms the pulmonary ligament

As lungs move and inflate, bronchi have more space to move

Question 17

What are the subdivisions of parietal pleura and their innervations

Answer 17

Cervical and costal pleura, supplied by intercostal nerves
Mediastinal pleura, covers mediastinum, gaps present for vessels, nerves, lymphatics which enter here
Diaphragmatic pleura, covers diaphragm, supplied by phrenic nerve C3-5

Question 18

What happens in a collapsed lung

Answer 18

If parietal punctured, -ve Pl lost, lung recoils inwards

If visceral punctured in cancer, -ve P lost

Question 19

Describe the vasculature and nervous innervation of diaphragm

Answer 19

phrenic nerves C3-5
R phrenic passes with VC
L phrenic passes through on its own
Phrenics pass in front of scalene ant and subclavian artery

Inf phrenic arteries branch off AA
Thoracic duct runs along AA

Venous drainage via azygos and hemiazygos

Question 20

Function of the openings in the diaphragm

Answer 20

Caval opening

• When D contracted, venous return aided
• -ve P in thorax and decreased diameter draws blood in
• NOT T8

Aortic opening

• Aorta passes behind diaphragm, so not compressed during contraction
• NOT T12

Oesophageal opening

• In L hemidiaphragm
• R crus loops around and forms sphincter to prevent backflow of food, attaches to lumbar

Question 21

Muscular attachments to the diaphragm

Answer 21

Psoas major
Quadratus lumborum
-Attaches to R12 and ilium
-pulls diaphragm down to stabilise ribs in breathing

Lateral, medial and median arcuate ligaments come over psoas and QL