phrenic nerve sample questions based on neet pg , usmle, plab and fmge pattern (mci screening)

26/04/2015

http://neetpgquiz.medicoapps.org/index.php?tid=15 1/4

Q:1Which of the following nerve provides motor supply to the diaphragm?A: Phrenic nerveB: Intercostal nervesC: Thoracodorsal nerveD: Sympathetic nervesCorrect Ans:AExplanation

Motor supply of the diaphragm on each side is by the phrenic nerve (C3, 4, 5).

Sensory innervation of the central pleura on the upper surface of the diaphragm and the peritoneum on thelower surface is by phrenic nerve.

Sensory innervation of the peripheral parts of the pleura and and peritoneum covering the peripheral areas of theupper and lower surfaces of the diaphragm is from the lower six thoracic nerves.

Phrenic nerve arises in the neck from the third, fourth and fifth cervical nerves of the cervical plexus. It alsosends branches to the pericardium, the mediastinal pleura, and the pleura and peritoneum covering the upperand lower surfaces of the central part of the diaphragm.

Ref: Clinical anatomy for Medical Students By Richard S Snell, 6th Edition, Pages556 ; B.D.Chaurasia’s Human Anatomy, 5th Edition, Volume 2, Pages 337338

Sample Previous Year Question on Phrenic Nerve based on previous Year Questions of NEET PG,USMLE,PLAB,FMGE (MCI Screening). Please visit www.medicoapps.org for more such Quizzes

Q:2 All are true about right phrenic nerve except?A: Motor branchB: Sensory branchC: Arises from C4D: Longer course than left Phrenic nerveCorrect Ans:DExplanation

The phrenic nerve is a mixed nerve which gives its sole motor supply to the diaphragm. Arises from C35 mainlyfrom C4 the right phrenic nerve is shorter and more vertical than left.

Ref: BD Chaurasia 4th ed vol 2 Page 311


Q:3Which one of the following DOES NOT lie within the posterior mediastinum?A: Phrenic nerveB: Vagus nerve

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C: EsophagusD: Thoracic aortaCorrect Ans:AExplanation

Phrenic nerve lies in the superior mediastinum and not in the posterior mediastinum. All other choices lieswithin the posterior mediastinum.

Posterior mediastinum: The region containing anatomic structures deep to the pericardial sac, including thethoracic portion of the descending aorta, the azygos system of veins, the thoracic duct, the esophagus, and thevagus and sympathetic nerves.

Also Know:

Superior mediastinum: The region superior to the sternal angle containing the aortic arch and its threebranches, the superior vena cava (SVC) and the brachiocephalic veins, the trachea, the esophagus, andthe phrenic and vagus nerves. The superior mediastinum also contains the thymus; however, in an adult,the thymus is usually atrophied and presents as a fatty mass.Anterior mediastinum: The region between the sternal angle, the deep sternal surface, the pericardialsac, and the diaphragm. The anterior mediastinum contains fat and areolar tissue and the inferior part ofthe thymus or its remnant.Middle mediastinum: This region contains the pericardial sac and heart.

Ref: Morton D.A., Foreman K.B., Albertine K.H. (2011). Chapter 5. Superior and Posterior Mediastina. In D.A.Morton, K.B. Foreman, K.H. Albertine (Eds), The Big Picture: Gross Anatomy.Sample Previous Year Question on Phrenic Nerve based on previous Year Questions of NEET PG,USMLE,PLAB,FMGE (MCI Screening). Please visit www.medicoapps.org for more such Quizzes

Q:4 The key to the root of the neck is the scalenus anterior muscle. Which among the following isTRUE about scalenus anterior?

A:B: Attached to scalene tubercle on 2nd ribC: Separates subclavian artery from subclavian veinD: Pierced by phrenic nerveCorrect Ans:BExplanation

The subclavian vein forms an arch across the pleura at a level below the arch of subclavian artery. The twoarches are separated from each other by scalenus anterior muscle.

Scalenus anterior arises from the anterior tubercles of C3C6 and attaches to the scalene tubercle and adjacentridge on the inner border and upper surface of the first rib.

Phrenic nerve passes vertically down across the obliquity of the muscle, plastered there to by the prevertebralfascia.

Transcervical and suprascapular arteries lie between the scalenus anterior and the carotid sheath.

Ref: Lasts Anatomy Regional & Applied 9e Rpr By Mcminn, 2003, Page 442; BDC 4th edition, IIIrd volume, Page198


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Q:5 In a case of chest pain with pericarditis and pericardial effusion, pain is referred by?A: Superficial cardiac plexusB: Phrenic nerveC: Deep cardiac plexusD: Vagus nerveCorrect Ans:BExplanationThe phrenic nerve arises from the ventral rami of cervical spinal nerves C3–5 and courses down in theprevertebral fascia, in front of the anterior scalene muscle, into the thorax between the subclavian artery andvein. It provides motor innervation to the diaphragm. In addition, it carries sensation from the mediastinal anddiaphragmatic parietal pleura, the pericardium, and the parietal peritoneum under the diaphragm. The fibrousand parietal pericardial are supplied by the phrenic nerve (C3C5). They are sensitive to pain. The visceralpericardium or epicardium is supplied by autonomic nerves, not sensitive to pain. Ref: Dhillon N. (2012). Chapter 1. Anatomy. In A.K. Lalwani (Ed), CURRENT Diagnosis & Treatment inOtolaryngology—Head & Neck Surgery, 3e.


Q:6 All of the following structures pass through aortic opening in the diaphragm, EXCEPT :A: Azygos veinB: Rt. phrenic nerveC: Thoracic ductD: Accessory Hemiazygos veinCorrect Ans:BExplanationAzygos vein pass to the right and thoracic duct passes to the left of aorta through its opening in the diaphragm.Accessory hemiazygos vein and hemiazygos veins pass behind the aorta and thoracic duct to join the azygos veinopposite the seventh and eighth thoracic thoracic vertebral bodies. Aortic opening in the diaphragm lies at the lower border of body of T12. Oesophageal opening of diaphragm lies at the level of lower border of T10 vertebrae. Structures passingthrough it are: oesophagus, oesophageal branches of left gastric artery, anterior gastric nerve and posteriorgastric nerve. Right phrenic nerve passes through the vena caval opening in the diaphragm which lies at level of lowerborder of T8 vertebrae. Ref: A New Approach to Dissection of the Human Body: A Thirty Week Schedule By R. Kanagasuntheram page71. Anatomy, Combined Edition By S. Mitra page 143.Sample Previous Year Question on Phrenic Nerve based on previous Year Questions of NEET PG,USMLE,PLAB,FMGE (MCI Screening). Please visit www.medicoapps.org for more such Quizzes

Q:7Which of the following nerve provides motor supply to the diaphragm?A: Phrenic nerve

26/04/2015


B: Intercostal nervesC: Thoracodorsal nerveD: Sympathetic nervesCorrect Ans:AExplanation

Motor supply of the diaphragm on each side is by the phrenic nerve (C3, 4, 5).

Sensory innervation of the central pleura on the upper surface of the diaphragm and the peritoneum on thelower surface is by phrenic nerve.

Sensory innervation of the peripheral parts of the pleura and and peritoneum covering the peripheral areas of theupper and lower surfaces of the diaphragm is from the lower six thoracic nerves.

Phrenic nerve arises in the neck from the third, fourth and fifth cervical nerves of the cervical plexus. It alsosends branches to the pericardium, the mediastinal pleura, and the pleura and peritoneum covering the upperand lower surfaces of the central part of the diaphragm.

Ref: Clinical anatomy for Medical Students By Richard S Snell, 6th Edition, Pages556 ; B.D.Chaurasia’s Human Anatomy, 5th Edition, Volume 2, Pages 337338


phrenic nerve sample questions based on neet pg , usmle, plab and fmge pattern (mci screening)

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