NEET-PG 2015 Practice Questions

Q: What muscle is attached to the superior nuchal line?

Trapezius muscle. ***Trapezius muscle*** - The **trapezius muscle** is a large, triangular muscle of the back that extends from the **occipital bone** (including the superior nuchal line) to the lower thoracic vertebrae. - Its **superior fibers** originate from the **medial one-third of the superior nuchal line** and the external occipital protuberance. *Scalenus anterior* - The **scalenus anterior** muscle originates from the **transverse processes of cervical vertebrae**, specifically C3-C6. - It inserts onto the **first rib** and is involved in neck flexion and elevation of the first rib during forced inspiration. *Coracobrachialis muscle* - The **coracobrachialis muscle** originates from the **coracoid process of the scapula**. - It inserts into the **medial surface of the humerus** and is involved in shoulder flexion and adduction. *Biceps Brachii muscle* - The **biceps brachii muscle** has two heads: the short head originates from the **coracoid process**, and the long head originates from the **supraglenoid tubercle of the scapula**. - It inserts onto the **radial tuberosity** and is primarily responsible for elbow flexion and forearm supination.

Q: Which of the following structures is not related to the third part of the duodenum?

Quadrate lobe of liver. ***Quadrate lobe of liver*** - The **quadrate lobe of the liver** is located on the visceral surface of the liver, bounded by the gallbladder fossa, ligamentum teres, and porta hepatis. [1] - It is anatomically related to the **first part of the duodenum** and the pylorus, but has **no direct relationship** with the retroperitoneal **third part of the duodenum**, which lies at the L3 vertebral level. [2] - The third part of the duodenum is too inferior and posterior to have any relationship with the quadrate lobe. *Superior mesenteric vessels* - The **superior mesenteric artery** and **vein** cross **anteriorly** to the **third part of the duodenum** as it runs horizontally from right to left. - The duodenum passes between the aorta posteriorly and the superior mesenteric vessels anteriorly, creating a potential site for compression (**superior mesenteric artery syndrome**). *Right ureter* - The **right ureter** is a **posterior relation** of the **third part of the duodenum**, as both structures are retroperitoneal. [2] - The ureter descends on the psoas major muscle, passing behind the third part of the duodenum during its course toward the pelvis. *Head of pancreas* - The **head of pancreas**, specifically the **uncinate process**, lies **superior and posterior** to the **third part of the duodenum**. - The uncinate process hooks around posteriorly to the superior mesenteric vessels and has an intimate relationship with the third part of the duodenum.

Q: Which nerve is preserved in dissecting the superficial and deep lobes of the parotid gland?

Facial. ***Correct: Facial*** - The **facial nerve (CN VII)** passes directly through the parotid gland, dividing it into superficial and deep lobes. Dissection of these lobes requires careful identification and preservation of the facial nerve and its branches to avoid paralysis. - Injury to the facial nerve during parotidectomy can lead to various degrees of **facial paralysis**, affecting muscle movements like smiling, eye closure, and forehead wrinkling. *Incorrect: Glossopharyngeal* - The **glossopharyngeal nerve (CN IX)** supplies the carotid sinus and stylopharyngeus muscle and provides secretomotor innervation to the parotid gland via the otic ganglion. - It does not traverse the parotid gland itself, so it is not directly at risk during the dissection of the superficial and deep lobes. *Incorrect: Hypoglossal* - The **hypoglossal nerve (CN XII)** primarily controls the intrinsic and extrinsic muscles of the tongue, responsible for tongue movement. - It is located inferior to the parotid gland and is not in the field of dissection for separating the parotid lobes. *Incorrect: Lingual* - The **lingual nerve**, a branch of the mandibular nerve (CN V3), provides sensation to the **anterior two-thirds of the tongue** and carries parasympathetic fibers for submandibular and sublingual glands. - While it is in the general vicinity of the orofacial region, it does not pass through the parotid gland and is therefore not directly at risk during the dissection of the parotid lobe.

Q: Which intrinsic ocular muscle responsible for pupillary constriction is supplied by parasympathetic innervation?

Constrictor pupillae. ***Constrictor pupillae*** - The **constrictor pupillae** (or **sphincter pupillae**) muscle is responsible for **miosis** (pupil constriction) and is innervated by **parasympathetic fibers** from the **oculomotor nerve (CN III)** via the **ciliary ganglion** [1]. - Stimulation of this muscle reduces the pupil size, which is a key part of the **light reflex** and **accommodation reflex** [1]. - This is the **only pupillary muscle** with parasympathetic innervation. *Ciliary muscle* - The **ciliary muscle** is involved in **accommodation**, altering the shape of the lens for focusing on near objects [1]. - While it also receives **parasympathetic innervation** from the ciliary ganglion, it does **not control pupil size**. - Its function is to change **lens curvature**, not pupillary diameter. *Levator palpebrae superioris* - This muscle is responsible for **elevating the upper eyelid**. - It is innervated by the **somatic motor fibers** of the **oculomotor nerve (CN III)**, not parasympathetic fibers. - It is **not an intrinsic ocular muscle** but rather an extraocular muscle. *Dilator pupillae* - The **dilator pupillae** muscle causes **mydriasis** (pupil dilation). - This muscle is innervated by **sympathetic fibers**, originating from the superior cervical ganglion, not parasympathetic fibers.

Q: Lips do not drain into which group of lymph nodes?

Preauricular parotid. ***Preauricular parotid*** - Lymph from the lips primarily drains into the **submental**, **submandibular**, and **deep cervical lymph nodes** [1]. - **Preauricular parotid nodes** primarily drain the lateral surface of the auricle, external auditory canal, temporoparietal scalp, and lateral parts of the eyelids and cheek. - The lips do **NOT** drain into preauricular nodes. *Submandibular nodes* - The **lateral parts of the lower lip** and the **entire upper lip** drain into the submandibular lymph nodes [1]. - These nodes are a primary drainage pathway for the oral region. *Submental nodes* - The **central part of the lower lip** drains into the submental lymph nodes [1]. - These nodes lie between the anterior bellies of the digastric muscles beneath the chin. - They receive lymph from the central lower lip, floor of mouth, and tip of tongue. *None of the options* - This option is incorrect because there is a specific group of nodes listed that the lips do *not* drain into (preauricular parotid).

Q: Which nerve supplies the postganglionic fibers to the parotid gland?

Auriculotemporal nerve. ***Auriculotemporal nerve*** - This nerve carries the **postganglionic parasympathetic fibers** from the **otic ganglion** to the parotid gland, stimulating saliva production. - These fibers originate from the **glossopharyngeal nerve (CN IX)**, synapse in the otic ganglion, and then join the auriculotemporal nerve. *Glossopharyngeal nerve* - The glossopharyngeal nerve (CN IX) provides the **preganglionic parasympathetic fibers** that ultimately reach the parotid gland. - These preganglionic fibers synapse in the **otic ganglion**, not directly supply the gland with postganglionic fibers. *Facial nerve* - The facial nerve (CN VII) supplies the **submandibular** and **sublingual glands** with parasympathetic innervation, via the chorda tympani and submandibular ganglion. - It does not innervate the parotid gland for salivary secretion. *Greater superficial petrosal nerve* - This nerve (a branch of the facial nerve) carries **preganglionic parasympathetic fibers** to the pterygopalatine ganglion, innervating the **lacrimal gland** and glands in the nasal and oral cavities. - It is not involved in the postganglionic innervation of the parotid gland.

Q: Secretomotor fibers to parotid gland are through?

Tympanic plexus. This is an easy question, and the expected Bloom's level is low (L1) with an expectation of just remembering the right answer. ***Tympanic plexus*** - The secretomotor fibers to the parotid gland originate from the inferior **salivatory nucleus**, travel via the **glossopharyngeal nerve (CN IX)** to the tympanic plexus. - From the tympanic plexus, these preganglionic parasympathetic fibers form the **lesser petrosal nerve**, which synapses in the otic ganglion, and postganglionic fibers then join the **auriculotemporal nerve** to reach the parotid gland. *Greater petrosal nerve* - The **greater petrosal nerve** carries preganglionic parasympathetic fibers that primarily innervate the **lacrimal gland** and glands of the nasal cavity and palate, not the parotid gland. - It is a branch of the **facial nerve (CN VII)**, whereas secretomotor innervation to the parotid is from the glossopharyngeal nerve (CN IX). *Geniculate ganglion* - The **geniculate ganglion** is a sensory ganglion of the **facial nerve (CN VII)**, containing cell bodies for taste sensation from the anterior two-thirds of the tongue. - It is not directly involved in transmitting secretomotor fibers to the parotid gland. *None of the options* - As the **tympanic plexus** is the correct conduit for the secretomotor fibers to the parotid gland, this option is incorrect. - The pathway involves a specific sequence of nerves and ganglia, which includes the tympanic plexus as a key relay point.

Q: Which of the following muscles is not supplied by the femoral nerve?

Obturator externus. ***Obturator externus*** - The **obturator externus** muscle is primarily supplied by the **obturator nerve** (L3-L4), which arises from the lumbar plexus, not the femoral nerve. - Its main function is the **lateral rotation of the thigh** at the hip joint. *Pectineus* - The **pectineus** muscle receives dual innervation, typically from both the **femoral nerve** (L2-L4) and the obturator nerve. - It aids in **adduction**, **flexion**, and **medial rotation** of the thigh. *Sartorius* - The **sartorius** muscle is entirely supplied by the **femoral nerve** (L2-L3). - It is responsible for **flexing, abducting, and laterally rotating the thigh** at the hip, and flexing the leg at the knee. *Vastus medialis* - The **vastus medialis** is one of the four muscles forming the quadriceps femoris group, all of which are exclusively supplied by the **femoral nerve** (L2-L4). - This muscle is crucial for **extending the leg** at the knee joint.

Q: Floor of Petit triangle is formed by?

Internal oblique muscle. ***Internal oblique muscle*** - The **Petit triangle** (lumbar triangle) is a landmark defined by the **latissimus dorsi posteriorly**, the **external oblique anteriorly**, and the **iliac crest inferiorly**. - Its **floor** is consistently formed by the **internal oblique muscle**, which lies deep to the external oblique [1]. *Sacrospinalis muscle* - The **sacrospinalis muscle** (erector spinae) is part of the deep back muscles, located medial to the Petit triangle. - It forms part of the **vertebral column's musculature** and is not directly associated with the floor of the Petit triangle. *Rectus abdominis muscle* - The **rectus abdominis muscle** is located medially in the anterior abdominal wall [1]. - It is distinct from the lateral abdominal wall muscles that form the boundaries and floor of the Petit triangle. *Fascia Transversalis layer* - The **fascia transversalis** is a deeper fascial layer lining the abdominal wall. - While it's deep to the internal oblique, the **muscle itself** forms the immediate anatomical floor of the Petit triangle.

Q: In a patient experiencing a stress response, which structure acts as the major central coordinator of the sympathetic nervous system?

Hypothalamus. ***Hypothalamus*** - The **hypothalamus** is the primary subcortical region that integrates stress responses by coordinating the **autonomic nervous system** and the **endocrine system**. - It directly regulates the **sympathetic nervous system** activation during stress through its projections to lower brainstem and spinal cord centers. *Nucleus ambiguus* - This nucleus is primarily involved in the motor control of the **pharynx, larynx, and esophagus**, as well as controlling the **parasympathetic innervation of the heart**. - While part of the autonomic system, it is not the major central coordinator of the sympathetic stress response. *Nucleus tractus solitarius* - The **nucleus tractus solitarius (NTS)** receives visceral sensory input from cranial nerves (e.g., vagus nerve) and plays a role in cardiovascular and respiratory reflexes. - It influences the autonomic nervous system but acts as a relay and integration center for specific reflexes rather than the overall central coordinator of the stress response. *Edinger-Westphal nucleus* - The **Edinger-Westphal nucleus** is a preganglionic parasympathetic nucleus that controls the **pupillary light reflex** and **accommodation (lens focusing)**. - Its function is related to the parasympathetic division but not as the central coordinator of the systemic sympathetic stress response.

Question 1

What muscle is attached to the superior nuchal line?

Accepted Answer

Trapezius muscle

Answer

Scalenus anterior

Answer

Coracobrachialis muscle

Answer

Biceps Brachii muscle

Question 2

Which of the following structures is not related to the third part of the duodenum?

Accepted Answer

Quadrate lobe of liver

Answer

Superior mesenteric vessels

Answer

Right ureter

Answer

Head of pancreas

Question 3

Which nerve is preserved in dissecting the superficial and deep lobes of the parotid gland?

Accepted Answer

Facial

Answer

Glossopharyngeal

Answer

Hypoglossal

Answer

Lingual

Question 4

Which intrinsic ocular muscle responsible for pupillary constriction is supplied by parasympathetic innervation?

Accepted Answer

Constrictor pupillae

Answer

Dilator pupillae

Answer

Levator palpebrae superioris

Answer

Ciliary muscle

Question 5

Lips do not drain into which group of lymph nodes?

Accepted Answer

Preauricular parotid

Answer

Submandibular nodes

Answer

None of the options

Answer

Submental nodes

Question 6

Which nerve supplies the postganglionic fibers to the parotid gland?

Accepted Answer

Auriculotemporal nerve

Answer

Glossopharyngeal nerve

Answer

Facial nerve

Answer

Greater superficial petrosal nerve

Question 7

Secretomotor fibers to parotid gland are through?

Accepted Answer

Tympanic plexus

Answer

Greater petrosal nerve

Answer

Geniculate ganglion

Answer

None of the options

Question 8

Which of the following muscles is not supplied by the femoral nerve?

Accepted Answer

Obturator externus

Answer

Pectineus

Answer

Sartorius

Answer

Vastus medialis

Question 9

Floor of Petit triangle is formed by?

Accepted Answer

Internal oblique muscle

Answer

Sacrospinalis muscle

Answer

Rectus abdominis muscle

Answer

Fascia Transversalis layer

Question 10

In a patient experiencing a stress response, which structure acts as the major central coordinator of the sympathetic nervous system?

Accepted Answer

Hypothalamus

Answer

Nucleus ambiguus

Answer

Nucleus tractus solitarius

Answer

Edinger-Westphal nucleus

NEET-PG 2015

Anatomy

Physiology