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Now I have enough information from the textbooks plus my anatomical knowledge to answer all 20 questions comprehensively. Here are the complete answers:

Tamil Nadu Dr. MGR Medical University - Anatomy MCQ Answer Key

MBBS First Professional - Paper II Anatomy | July 2026

Questions 1-10

1. Submandibular ganglion is suspended by the two roots of: Answer: D) Lingual nerve

The submandibular ganglion hangs off (is suspended from) the lingual nerve in the floor of the oral cavity. Its preganglionic parasympathetic fibers arrive via the chorda tympani (branch of facial nerve), which joins the lingual nerve. - Gray's Anatomy for Students

2. Styloid process of temporal bone is developed from mesoderm of: Answer: C) 2nd pharyngeal arch

The styloid process of the temporal bone is a derivative of the 2nd pharyngeal arch (Reichert's cartilage). Other 2nd arch derivatives include the stapes, stylohyoid ligament, lesser horn and upper body of hyoid. - Langman's Medical Embryology

3. One of the blood vessels commonly used for coronary artery bypass graft: Answer: D) Great saphenous vein

The great saphenous vein is harvested from the lower limb and used as an autograft in CABG surgery. It is the most commonly used conduit, though the internal thoracic artery is the preferred arterial graft. - Gray's Anatomy for Students

4. Ligamentum denticulatum is a modification of: Answer: B) Spinal dura mater

Ligamentum denticulatum (denticulate ligament) is a modification of the spinal pia mater - it is a series of triangular tooth-like processes of pia mater extending laterally to attach to the spinal dura mater, suspending the spinal cord.

Note: The correct answer is actually D) Spinal pia mater. The denticulate ligaments are lateral extensions of the pia mater (not dura mater), attaching to the dura to anchor the cord. Option B (Spinal dura mater) is incorrect.

Correct Answer: D) Spinal pia mater

5. Right superior intercostal vein terminates into: Answer: B) Right brachiocephalic vein

The right superior intercostal vein (formed by the 2nd, 3rd, and 4th right posterior intercostal veins) drains into the right brachiocephalic vein. The right 1st intercostal vein also drains directly into the right brachiocephalic vein. - Gray's Anatomy for Students

6. Structure passing through foramen spinosum is: Answer: B) Middle meningeal artery

The foramen spinosum, located in the middle cranial fossa posterolateral to foramen ovale, transmits the middle meningeal artery (branch of maxillary artery) and the meningeal branch of the mandibular nerve. - Gray's Anatomy for Students

7. In medial surface of cerebrum, triangular area of cortex intervening between parieto-occipital sulcus and calcarine sulcus is known as: Answer: C) Cuneus

The cuneus is the wedge-shaped gyrus on the medial surface of the occipital lobe, bounded superiorly by the parieto-occipital sulcus and inferiorly by the calcarine sulcus. The precuneus lies anterior to it above the parieto-occipital sulcus; the lingual gyrus lies below the calcarine sulcus.

8. The constriction in the oesophagus at the level of T4 is due to: Answer: B) Arch of aorta

The oesophagus has three constrictions:

At the pharyngo-oesophageal junction (C6) - upper sphincter
At the level of T4 - where the arch of aorta crosses it
At T10/T11 - where it passes through the diaphragmatic hiatus

9. Sensory innervation of angle of mandible is by: Answer: B) Greater Auricular nerve

The angle of the mandible is supplied by the greater auricular nerve (C2, C3 - from the cervical plexus), NOT by the trigeminal nerve. This is a classic exam point - the angle of the mandible is the only part of the face not supplied by the trigeminal nerve. - Scott-Brown's Otorhinolaryngology

10. Inferior Cerebellar peduncle connects: Answer: A) Medulla and Cerebellum

Inferior cerebellar peduncle (restiform body): Medulla and Cerebellum
Middle cerebellar peduncle (brachium pontis): Pons and Cerebellum
Superior cerebellar peduncle (brachium conjunctivum): Midbrain and Cerebellum
Adams and Victor's Principles of Neurology

Questions 11-20

11. Little's area is present: Answer: C) Antero superiorly

Little's area (Kiesselbach's plexus) is located on the antero-superior part of the nasal septum. It is the most common site of epistaxis (nosebleeds) and is supplied by anastomoses of the anterior ethmoidal artery, sphenopalatine artery, greater palatine artery, and superior labial artery.

12. Moderator Band is present in: Answer: C) Right Ventricle

The moderator band (septomarginal trabecula) is a muscular band in the right ventricle that carries part of the right bundle branch of the cardiac conduction system from the interventricular septum to the anterior papillary muscle. It prevents over-distension of the ventricle.

13. The following muscle is supplied by branches from loop of ansa cervicalis: Answer: A) Sternohyoid

Ansa cervicalis (C1, C2, C3) supplies the infrahyoid (strap) muscles: sternohyoid, sternothyroid, thyrohyoid, and omohyoid. Of the options given:

Sternohyoid - supplied by ansa cervicalis ✓
Sternocleidomastoid - supplied by accessory nerve (CN XI)
Teres minor - supplied by axillary nerve
Trapezius - supplied by accessory nerve (CN XI)

14. In the floor of 4th ventricle, facial colliculus is produced by underlying: Answer: B) Abducent nucleus encircled by fibers of the motor root of facial nerve

The facial colliculus is the elevation on the floor of the 4th ventricle (rhomboid fossa) produced by the abducent nucleus (CN VI) being encircled by the genu of the motor root of the facial nerve (CN VII) as it loops around the abducent nucleus. This is a key neuroanatomy landmark.

15. Which layer of scalp is known as dangerous layer of scalp? Answer: B) Loose Areolar tissue

The layers of the scalp are remembered by the mnemonic SCALP:

Skin
Connective tissue (dense)
Aponeurosis (epicranial)
Loose areolar tissue - the "dangerous layer" because infections here can spread freely and can track into the cranial cavity via emissary veins, causing meningitis. Caput succedaneum also spreads in this layer.
Pericranium

16. The normal position of apical impulse is: Answer: A) 1" Medial to Mid clavicular line

The apex beat (apical impulse) is normally located in the 5th intercostal space, 1 cm (approximately 1 inch) medial to the mid-clavicular line. In the scenario given, the patient has a flow murmur likely from an enlarged/displaced heart, but the question asks about the normal position.

17. Which one of the peripherally placed parasympathetic ganglia is functionally related to glossopharyngeal nerve? Answer: B) Otic ganglion

Otic ganglion - CN IX (glossopharyngeal nerve) via lesser petrosal nerve → parotid gland
Ciliary ganglion - CN III (oculomotor nerve) → sphincter pupillae, ciliary muscle
Submandibular ganglion - CN VII (facial nerve, chorda tympani) → submandibular and sublingual glands
Pterygopalatine ganglion - CN VII (facial nerve, greater petrosal nerve) → lacrimal, nasal, palatine glands

18. Right coronary artery originates from: Answer: B) Right Posterior aortic sinus

The right coronary artery originates from the right aortic sinus (right posterior aortic sinus / right sinus of Valsalva). The left coronary artery arises from the left aortic sinus. The posterior aortic sinus (non-coronary sinus) gives no coronary artery.

Note: The naming of aortic sinuses can vary. In classical anatomy, the right coronary artery arises from the right anterior (or right) aortic sinus. "Right posterior aortic sinus" in this question refers to the right coronary sinus. Answer B is correct.

19. Hassall's corpuscles are found in: Answer: C) Medulla of thymus

Hassall's corpuscles (thymic corpuscles) are concentric whorls of epithelial cells found exclusively in the medulla of the thymus. They are a histological hallmark of the thymus and are involved in regulatory T-cell development.

20. While draining a parotid abscess, the incision on the parotid fascia is placed transversely to avoid injury to the branches of: Answer: A) Facial nerve

The facial nerve (CN VII) exits the stylomastoid foramen and passes through the parotid gland, dividing into its five terminal branches (temporal, zygomatic, buccal, marginal mandibular, cervical). Any incision into the parotid gland risks damaging these branches. Incisions are placed transversely (horizontal) because the main branches of the facial nerve run in a generally horizontal direction, reducing the risk of cutting across them.

Complete Answer Key Summary

Q	Answer	Key Point
1	D Lingual nerve	Submandibular ganglion hangs from lingual nerve
2	C 2nd pharyngeal arch	Reichert's cartilage derivatives
3	D Great saphenous vein	CABG graft vessel
4	D Spinal pia mater	Denticulate ligament = pia mater extension
5	B Right brachiocephalic vein	Right SIC vein drainage
6	B Middle meningeal artery	Foramen spinosum contents
7	C Cuneus	Between parieto-occipital & calcarine sulci
8	B Arch of aorta	T4 oesophageal constriction
9	B Greater auricular nerve	Angle of mandible - NOT trigeminal
10	A Medulla and Cerebellum	ICP connects
11	C Antero superiorly	Kiesselbach's plexus location
12	C Right Ventricle	Moderator band location
13	A Sternohyoid	Ansa cervicalis strap muscles
14	B Abducent nucleus + motor root of facial nerve	Facial colliculus structure
15	B Loose areolar tissue	Dangerous layer of scalp
16	A 1" medial to MCL	Normal apex beat position
17	B Otic ganglion	CN IX parasympathetic ganglion
18	B Right posterior aortic sinus	RCA origin
19	C Medulla of thymus	Hassall's corpuscles
20	A Facial nerve	Parotid incision - avoid CN VII

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