Thorax

Question 1

What are true ribs?

Answer 1

Where the costal cartilage attaches directly to the sternum. Ribs 1-7.

Question 2

What are false ribs?

Answer 2

Where the costal cartilage attaches to the cartilage above. Ribs 8-10.

Question 3

What are floating ribs?

Answer 3

Do not attach to the sternum at all. Ribs 11 and 12. They have rudimentary cartilage that ends in abdominal muscle wall rather than connecting to sternum.

Question 4

Give details on the external intercostal muscles.

Answer 4

Occupy intercostal spaces from posterior to costochondral junction. Fibres run anterioinferiorly. Most active during inspiration.

Question 5

Give details on the internal intercostal muscles.

Answer 5

Occupy intercostal spaces from anterior to angle of the ribs. Fibres run anteroposteriorly. Most active during expiration.

Question 6

Where is the neurovascular bundle found?

Answer 6

Between the internal and innermost intercostal muscle.

Question 7

From where do the intercostal nerves come from?

Answer 7

Anterior rami of T1-T11 spinal nerves form intercostal nerves. Anterior ramus of T12 spinal nerve forms subcostal nerve.

Question 8

What are pleural recesses?

Answer 8

Potential spaces between the costal and diaphragmantic pleura that the lungs can move into during inspiration.

Question 9

Why is the sternal angle useful clinically?

Answer 9

It corresponds to the level of the 2nd costal cartilage. We can then use the sternal angle to locate different intercostal spaces.

Question 10

At what vertebral level is the sternal angle and what structures are transected by a horizontal section through it?

Answer 10

Passes through T4/5 vertebral disc. It divides the mediastinum into superior and inferior parts. A cross section passes through:

• bifurcation of the trachea.
• superior limit of pericardium.
• the start and end of the aortic arch.
• superior vena cava.

Question 11

What are the characteristics of a thoracic vertebrae?

Answer 11

Have costal facets on bodies and transverse processes. Long, inferior slanting spinous process. Superior and inferior articular facets orientated in coronal plane which permit rotation.

Question 12

Why ribs have atypical articulations and explain how.

Answer 12

The head of the first rib only articulates with T1. The heads of ribs 10-12 only articulate with their corresponding vertebra (not demi- facets). Ribs 11 and 12 do not articulate with transverse processes.

Question 13

What is the safest route to insert a needle to perform a thoracentesis?

Answer 13

Superior to the rub, just high enough to avoid the collateral branches of the intercostal nerve.

Question 14

What are the attachments of the diaphragm?

Answer 14

• L1-L3 vertebrae.
• Inferior 6 costal cartilages and adjacent ribs.
• Xiphoid process.

Question 15

How far does the diaphragm move during quiet breathing vs. forced breathing?

Answer 15

1-2cm in quiet breathing. 6-10cm in forced breathing.

Question 16

What surgical procedure uses the internal thoracic artery?

Answer 16

Coronary artery bypass graft (CABG).

Question 17

What would happen to breathing in the case of a spinal cord injury at the level of C1/C2?

Answer 17

You would get paralysis of the diaphragm so would require mechanical ventilation.

Question 18

What is atelectasis?

Answer 18

A condition in which one or more areas of your lungs collapse or don’t inflate properly. If only a small area or a few small areas of the lungs are affected, you may have no signs or symptoms.
If a large area or several large areas of the lungs are affected, they may not be able to deliver enough oxygen to your blood. This can cause symptoms and complications.

Question 19

Where does the pleural cavity extend to superiorly?

Answer 19

2-3cm above the medial clavicle.

Question 20

What is a pneumothorax?

Answer 20

Air in the pleural cavity.

Question 21

What is a haemothorax?

Answer 21

Blood in the pleural cavity.

Question 22

What is a chylothorax?

Answer 22

Chyle (lipid rich lymph fluid) in the pleural cavity.

Question 23

What is empyema?

Answer 23

Pus in the pleural cavity eg. in pneumonia.

Question 24

What effect would obstruction of the bronchus have on the lung?

Answer 24

Atelectasis.

Question 25

Is an inhaled object more likely to block the left or right primary bronchi?

Answer 25

Right because it is shorter, wider and more vertical.

Question 26

What is pericardial effusion?

Answer 26

Excess fluid in the pericardial cavity.

Question 27

What is cardiac tamponade?

Answer 27

Compression of the heart due to excess fluid and fibrous pericardium.

Question 28

Stenosis (narrowing) of the aortic valve is a common abnormality. What effect would aortic stenosis have on the function of the heart?

Answer 28

Left ventricular hypertrophy.

Question 29

What is the ligamentum arteriosum a remnant of?

Answer 29

Ductus arteriosis.

Question 30

What vein drains into the superior vena cava?

Answer 30

Azygos vein.

Question 31

What is in the posterior mediastinum?

Answer 31

Oesphagus, descending thoracic aorta, azygos vein (and hemi-azygos) and thoracic duct.

Question 32

What is Virchow’s node?

Answer 32

The left supraclavicular node. It is the last shared pathway of lymph originating in the abdomen and so swelling of Virchow;s node is often the first sign of abdominal malignancy- Trosier’s sign.

Question 33

What is a hiatus hernia?

Answer 33

Protrusion of stomach through oesophageal hiatus in diaphragm. Seen in lateral X ray using barium swallow. . Causes reflux as stomach acid moves into oesophagus more easily. More common in over 50’s. Risk factors include anything that increase intra-abdominal pressure eg. heavy lifting and obesity.

Question 34

What is a congenital diaphragmatic hernia?

Answer 34

This is a congenital malformation of the diaphragm which leads to lung hypoplasia (underdevelopment) and has a high mortality rate.

Question 35

What is referred pain?

Answer 35

Phenomenon whereby visceral pain is not ‘felt’ in the organ but in the dermatomes related to the origin of its efferent (sympathetic) innervation.