AN25.1-9 | Thorax — Gate Quiz

Correct. Thoracic vertebrae are uniquely identified by their costal facets — on the vertebral body (demifacets) and on the transverse processes — for articulation with the ribs.

Thoracic vertebrae have costal facets for rib articulation — both on the vertebral body and the transverse processes.

Correct. The intercostal neurovascular bundle (VAN — vein, artery, nerve) runs in the costal groove under the lower border of each rib.

The VAN bundle runs in the costal groove under the lower border of the rib above. Inserting too close to this margin risks injuring the intercostal nerve, artery, and vein.

Correct. The oesophageal hiatus is at T10 and transmits the oesophagus along with the anterior and posterior vagal trunks.

"I 8 10 eggs at 12" — IVC at T8, Oesophagus at T10, Aorta at T12.

Correct. The cardiac apex beat (left ventricular impulse) is normally at the 5th left intercostal space in the midclavicular line.

The apex beat is normally at the 5th ICS, midclavicular line (left ventricular apex surface marking).

Correct. A cervical rib (bony opacity above the first rib on CXR) can compress the lower trunk of the brachial plexus (C8, T1) → wasting of intrinsic hand muscles + thoracic outlet syndrome.

A cervical rib causes thoracic outlet syndrome by compressing the lower trunk of the brachial plexus and/or subclavian artery.

Correct. The intercostal VAN bundle runs between the internal and innermost intercostal muscles, in the costal groove under the lower border of the rib above.

The VAN bundle runs between the internal intercostal and the innermost intercostal muscles.

Correct. The phrenic nerve (C3, C4, C5) carries sensory fibres from the central diaphragm. Stimulation of the C4 fibres refers pain to the C4 dermatome — the tip of the shoulder.

Phrenic nerve (C3–C5) — C4 fibres from the central diaphragm refer pain to the shoulder tip (C4 dermatome). Subphrenic irritation → shoulder tip pain.

Correct. Ribs 8–10 (false/vertebrochondral ribs) have costal cartilages that join the cartilage of the rib above, rather than attaching directly to the sternum.

Ribs 8–10 = false/vertebrochondral ribs. Their cartilages attach to the cartilage of the rib above (not the sternum). Ribs 11–12 are floating (no anterior attachment).

Correct. Coarctation obstructs flow; collateral vessels (internal thoracic and intercostal arteries) enlarge massively, eroding the inferior surface (costal groove) of the ribs 3–8.

Coarctation → increased flow through collateral intercostal arteries → these enlarge and pulsate → erode the inferior rib surface = rib notching on CXR.

Correct. In tension pneumothorax, air enters the pleural space but cannot exit (one-way valve). Pressure builds → pushes the mediastinum (including trachea) to the opposite side.

Tension pneumothorax = positive pressure building in the pleural space → mediastinal shift away from the side of the pneumothorax.