MLT GlobeAnatomy: Respiratory system – page 2
31 Anatomy MCQs on Respiratory system with answers and explanations.
During forced (laboured) inspiration, which accessory muscles lift the upper ribs and sternum?
Sternocleidomastoid and scalenes elevate the thoracic cage in forced inspiration. Internal intercostals and abdominal muscles assist forced expiration.
The lingual (front) surface of the epiglottis, exposed to swallowed food, is lined by:
Areas exposed to friction from food, like the lingual epiglottis, have stratified squamous epithelium; the lower laryngeal surface changes to respiratory epithelium.
A nasopharyngeal swab samples a surface lined mainly by:
The nasopharynx has respiratory (ciliated columnar) epithelium, the site sampled for many respiratory viruses; the oropharynx has stratified squamous.
In which phase of breathing is the diaphragm the principal active muscle?
Diaphragm contraction drives quiet inspiration; quiet expiration is passive elastic recoil. Forced expiration uses abdominal and internal intercostal muscles.
At about which vertebral level does the trachea divide into the two main bronchi?
The trachea bifurcates at the carina around the T4/T5 disc, level with the sternal angle. It begins at C6 below the cricoid cartilage.
The mediastinal (medial) surface of each lung:
The medial surface faces the mediastinum and heart (the cardiac impression) and has the hilum. The costal surface meets the ribs, and lungs are covered by visceral pleura.
During dissection of the root of the right lung, which finding would be unexpected?
Each hilum has one pulmonary artery, usually two pulmonary veins, the main bronchus, bronchial vessels, lymphatics and nerves.
The parietal pleura lines the thoracic cavity. Which structure is covered by visceral pleura instead and does not touch the parietal layer directly?
Parietal pleura lines the ribs, diaphragm and mediastinum. The lung surface is covered by visceral pleura, and the pleural cavity separates the two layers.
Which statement about the diaphragm is accurate?
The IVC passes through the central tendon at T8. The aorta passes behind the diaphragm through the aortic hiatus, not through the tendon. The phrenic nerve supplies it, and contraction flattens it.
The hilum of each lung, where the bronchus and vessels enter, lies roughly opposite which thoracic vertebrae?
The lung hila sit on the mediastinal surfaces at about T5–T7, just below the tracheal bifurcation.
Irritation of the central diaphragmatic and mediastinal parietal pleura causes pain referred to the shoulder, because these parts are supplied by the:
Phrenic nerve fibres (C3–C5) supply these pleural areas, so pain refers to the C4 shoulder dermatome. Costal pleura is supplied by intercostal nerves.