Free Thorax MCQs with Answers

• A. Subclavian vein
• B. Internal jugular vein
• C. External jugular vein
• D. Thoracic vein
• E. Brachiocephalic

Explanation: The superior vena cava is formed by the union of the right and left brachiocephalic veins behind the lower border of the first right…

• A. Azygos
• B. Subclavian
• C. Internal jugular
• D. Brachiocephalic

Explanation: The internal thoracic veins ascend beside the internal thoracic artery and unite with the brachiocephalic veins near the first costal…

• A. Highly susceptible to ischaemia
• B. Mainly supplied by right coronary
• C. Mainly supplied by left coronary
• D. Has a dual blood supply?

Explanation: The atrioventricular bundle receives a dual supply through the AV nodal artery, usually from the right coronary artery, and branches from…

• A. T1 - T3
• B. T2 - T6
• C. T3 - T7
• D. L1 - L5

Explanation: Cardiac sympathetic fibres arise from upper thoracic spinal segments, commonly described as T1 to T4 or T1 to T5, with some sources…

• A. Right and left
• B. Anterior and posterior
• C. Medial & Lateral
• D. Apical and inferior

Explanation: The right middle lobe is divided by a medial cleft into medial and lateral segments.

• A. Left atrium
• B. Left ventricle
• C. Right ventricle
• D. Right atrium

Explanation: The left atrium lies immediately anterior to the oesophagus, separated from it mainly by the pericardium.

• A. T2
• B. T3
• C. T4
• D. T6

Explanation: The carina lies at the sternal angle, corresponding approximately to the T4–T5 intervertebral level in adults.

• A. Vertebra and vertebral discs
• B. Interspinous ligaments
• C. Paraspinal muscle
• D. All

Explanation: Vertebral stability depends on the combined support of the vertebrae and discs, spinal ligaments such as the interspinous ligaments, and…

• A. Right and left ventricle
• B. Right atrium and ventricle
• C. Interventricular septum
• D. I.V.C. and right ventricle

Explanation: The diaphragmatic or inferior surface of the heart is formed mainly by the left ventricle, with a smaller contribution from the right…

• A. Right bronchus is more vertical and broader than the left
• B. Right bronchus is more vertical and has a narrow caliber than the left
• C. Left bronchus is more vertical and broader than right
• D. Left bronchus is more vertical and narrower than right

Explanation: The right main bronchus is shorter, wider and more vertical than the left, which is why aspirated foreign bodies more commonly enter it.

• A. Sternal angle
• B. 5th inter costal space
• C. 3rd thoracic vertebrae
• D. thoracic vertebrae

Explanation: The trachea bifurcates at the carina near the sternal angle, corresponding approximately to the T4-T5 intervertebral level.

• A. Bronchial artery
• B. Tracheal artery
• C. Inferior thyroid artery
• D. Superior thyroid artery

Explanation: The cervical trachea receives blood mainly from the inferior thyroid arteries, while the thoracic part is supplied by bronchial arteries.

• A. Lower end of cricoid
• B. C5 vertebra
• C. 10 cm from incisor teeth
• D. C7

Explanation: The oesophagus begins at the lower border of the cricoid cartilage, approximately opposite the C6 vertebra.

• A. 60 cm proximal to ileocecal junction
• B. 1stpart of duodenum
• C. Esophago gastric junction
• D. Pharyngo esophageal junction

Explanation: The pharyngoesophageal junction is the narrowest point of the gastrointestinal tract, owing mainly to the cricopharyngeus muscle.

• A. Fibrous joint
• B. Synovial joint
• C. Fmosis
• D. Synarthrosis

Explanation: The first costochondral joint is a primary cartilaginous joint, or synchondrosis, and is functionally immovable, making it a synarthrosis.

• A. Brachio cephalic trunk
• B. Ascending aorta
• C. Arch of aorta
• D. Left common carotid

Explanation: The left subclavian artery arises directly from the arch of the aorta, along with the brachiocephalic trunk and left common carotid…