INI-CET 2025 — Anatomy

Q: Which of the following is not a boundary of the hepatocystic triangle?

Cystic artery. ***Cystic artery*** - The **cystic artery** is the structure of key surgical importance found *within* the hepatocystic triangle, but it does not form one of its three defining boundaries [1]. - It is crucial for locating and ligating the artery during **cholecystectomy** [2]. *Cystic duct* - The **cystic duct** forms the **lateral boundary** of the hepatocystic triangle (Triangle of Calot) [1]. - This boundary leads directly from the neck of the gallbladder. *Common hepatic duct* - The **common hepatic duct** forms the **medial boundary** of the hepatocystic triangle [2]. - It is formed by the union of the right and left hepatic ducts and is medial to the cystic duct. *Inferior border of liver* - The **inferior border (or visceral surface) of the liver** forms the **superior boundary** of the hepatocystic triangle [2]. - Together with the cystic duct and common hepatic duct, it completes the triangular shape. [Practice more Anatomy PYQs on OnCourse]

Q: Observe the provided image showing a muscle indicated by an arrow. What is the primary action of this muscle on the mandible?

Protracts and depresses the mandible. ***Protracts and depresses the mandible*** - The muscle indicated is the **Lateral Pterygoid muscle**, which is unique among the muscles of mastication in being the primary muscle responsible for **mandibular depression** (opening the mouth). - The contraction of the muscle pulls the head of the mandible and the articular disc forward, leading to **protraction** and the initial phase of mouth opening. *Retracts and elevates the mandible* - These actions belong mainly to the **Temporalis muscle**. The anterior and middle fibers elevate and the posterior fibers retract the mandible. - The Lateral Pterygoid muscle is involved in lowering the jaw, which is contrary to elevation. *Elevates and protracts the mandible* - **Elevation** (closing the mouth) is the strongest action and is primarily carried out by the **Masseter**, **Temporalis**, and **Medial Pterygoid** muscles. - While the Lateral Pterygoid facilitates protraction, it is an antagonist to elevation. *Depresses and retracts the mandible* - The **Lateral Pterygoid** is the main muscle for **depression**; however, it causes **protraction** (forward movement) of the mandible, not retraction. - Retraction is primarily achieved by the **posterior fibers of the Temporalis muscle** and assisted by the digastrics muscle. [Practice more Anatomy PYQs on OnCourse]

Q: Tight junctions are primarily located at which part of the cell?

Apical. ***Apical*** - **Tight junctions** (Zonula Occludens) are the most **apical** component of the junctional complex in many epithelial cells [1]. - Their primary function is to seal adjacent cells, preventing the passage of molecules between them (paracellular route), thus establishing **epithelial polarity** [1], [2]. *Apicolateral* - This term is less precise; the junctional complex includes the tight junction (**apical**), followed by the adherens junction, and then the desmosome (**lateral**). - The tight junction itself is specifically located at the very **apical** edge, not spanning the entire apicolateral domain [1]. *Basal* - The **basal** part of the cell is where the cell attaches to the **basement membrane** via structures like hemidesmosomes [1]. - Tight junctions are not found here, as they are essential for defining the **apical** vs. basolateral domains. *Basolateral* - The **basolateral** domain comprises the sides and base of the cell, where structures like **desmosomes** (lateral) and hemidesmosomes (basal) are found [1]. - This region is separated from the lumen by the function of the **tight junction** located upstream at the apical pole [2]. [Practice more Anatomy PYQs on OnCourse]

Q: A middle-aged lady choked while eating fish and has associated symptoms of coughing, hoarseness of voice, and a foreign body sensation in the throat. On examination, the pyriform fossa is found to be inflamed. Which of the following nerves supplies this region?

Internal Laryngeal Nerve (ILN). ***Internal Laryngeal Nerve (ILN)*** - The **Internal Laryngeal Nerve** (sensory branch of **superior laryngeal nerve**, CN X) provides **sensory innervation to the pyriform fossa** and surrounding hypopharyngeal structures. - Fish bone impaction in the pyriform fossa irritates the **ILN**, causing **cough reflex**, **hoarseness**, and **foreign body sensation** as described in this case. *External Laryngeal Nerve (ELN)* - The **External Laryngeal Nerve** is primarily a **motor nerve** that supplies the **cricothyroid muscle** for vocal cord tensioning. - It provides **minimal sensory contribution** and does not innervate the mucosa of the pyriform fossa. *Glossopharyngeal Nerve* - The **Glossopharyngeal Nerve (CN IX)** provides sensory innervation to the **oropharynx** and **posterior third of tongue**, not the pyriform fossa. - The pyriform fossa is anatomically part of the **hypopharynx (laryngopharynx)**, which is supplied by branches of the **vagus nerve**, not CN IX. *Recurrent Laryngeal Nerve* - The **Recurrent Laryngeal Nerve** primarily provides **motor innervation** to intrinsic laryngeal muscles (except cricothyroid). - Its sensory distribution is limited to the **infraglottic larynx** (below vocal cords), not the pyriform fossa region. [Practice more Anatomy PYQs on OnCourse]

Q: Which of the following nerves gives sensory supply to the orbit?

Trigeminal nerve. ***Trigeminal nerve*** - The **Ophthalmic division (V1)** of the Trigeminal nerve (CN V) is the primary source of general sensation for structures within the orbit, including the globe, conjunctiva, and lacrimal gland. - Its key branches, which include the **frontal**, **lacrimal**, and **nasociliary nerves**, are responsible for carrying these sensory fibers. *Vagus nerve* - The Vagus nerve (CN X) is primarily involved in **parasympathetic control** of the thoracic and abdominal viscera, and motor supply to the pharynx and larynx. - It does not supply the orbit with any **general sensory** fibers; its distribution is mainly to the neck, chest, and abdomen. *Hypoglossal nerve* - The Hypoglossal nerve (CN XII) is a purely **somatic motor nerve** originating from the medulla. - Its function is restricted to supplying the **intrinsic and extrinsic muscles of the tongue**, having no role in orbital innervation or sensation. *Oculomotor nerve* - The Oculomotor nerve (CN III) is predominantly a **motor nerve** that supplies four of the six extraocular muscles and the **Levator palpebrae superioris**. - While it carries **parasympathetic fibers** to the ciliary ganglion, it does not provide **general sensory** supply to the orbital structures. [Practice more Anatomy PYQs on OnCourse]

16 Previous Year Questions with Answers & Explanations

Questions

Which of the following is not a boundary of the hepatocystic triangle?

Observe the provided image showing a muscle indicated by an arrow. What is the primary action of this muscle on the mandible?

Tight junctions are primarily located at which part of the cell?

A middle-aged lady choked while eating fish and has associated symptoms of coughing, hoarseness of voice, and a foreign body sensation in the throat. On examination, the pyriform fossa is found to be inflamed. Which of the following nerves supplies this region?

Which of the following nerves gives sensory supply to the orbit?

Out of the following, which statements are correct? 1. Epidermis can regenerate from hair bulbs and sebaceous glands 2. Stratum corneum is the outermost cellular layer 3. Epidermis originates from the ectoderm 4. Dermis and hypodermis originate from the endoderm

The dental numbering system shown below represents: R 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 (permanent teeth) and R e d c b a | a b c d e (deciduous teeth) for upper and lower quadrants. Which dental numbering system is this?

Identify the structure labeled in the histology image shown.

Tight junctions are primarily located at which part of the cell?

Q10

Match the cardiac anatomical features from Column I with their corresponding labels from Column II. Column I: 1. Receives oxygenated blood from pulmonary veins; 2. Lies anterior to ascending aorta; 3. Arises from LV; 4. Hypertrophy in pulmonary stenosis. Column II: A. Ascending aorta; B. Right ventricle; C. Pulmonary trunk; D. Left atrium.

INI-CET 2025 - Anatomy INI-CET Practice Questions and MCQs

Question 1: Which of the following is not a boundary of the hepatocystic triangle?

A. Cystic duct
B. Common hepatic duct
C. Cystic artery (Correct Answer)
D. Inferior border of liver

Explanation: ***Cystic artery*** - The **cystic artery** is the structure of key surgical importance found *within* the hepatocystic triangle, but it does not form one of its three defining boundaries [1]. - It is crucial for locating and ligating the artery during **cholecystectomy** [2]. *Cystic duct* - The **cystic duct** forms the **lateral boundary** of the hepatocystic triangle (Triangle of Calot) [1]. - This boundary leads directly from the neck of the gallbladder. *Common hepatic duct* - The **common hepatic duct** forms the **medial boundary** of the hepatocystic triangle [2]. - It is formed by the union of the right and left hepatic ducts and is medial to the cystic duct. *Inferior border of liver* - The **inferior border (or visceral surface) of the liver** forms the **superior boundary** of the hepatocystic triangle [2]. - Together with the cystic duct and common hepatic duct, it completes the triangular shape.

Question 2: Observe the provided image showing a muscle indicated by an arrow. What is the primary action of this muscle on the mandible?

A. Protracts and depresses the mandible (Correct Answer)
B. Retracts and elevates the mandible
C. Elevates and protracts the mandible
D. Depresses and retracts the mandible

Explanation: ***Protracts and depresses the mandible*** - The muscle indicated is the **Lateral Pterygoid muscle**, which is unique among the muscles of mastication in being the primary muscle responsible for **mandibular depression** (opening the mouth). - The contraction of the muscle pulls the head of the mandible and the articular disc forward, leading to **protraction** and the initial phase of mouth opening. *Retracts and elevates the mandible* - These actions belong mainly to the **Temporalis muscle**. The anterior and middle fibers elevate and the posterior fibers retract the mandible. - The Lateral Pterygoid muscle is involved in lowering the jaw, which is contrary to elevation. *Elevates and protracts the mandible* - **Elevation** (closing the mouth) is the strongest action and is primarily carried out by the **Masseter**, **Temporalis**, and **Medial Pterygoid** muscles. - While the Lateral Pterygoid facilitates protraction, it is an antagonist to elevation. *Depresses and retracts the mandible* - The **Lateral Pterygoid** is the main muscle for **depression**; however, it causes **protraction** (forward movement) of the mandible, not retraction. - Retraction is primarily achieved by the **posterior fibers of the Temporalis muscle** and assisted by the digastrics muscle.

Question 3: Tight junctions are primarily located at which part of the cell?

A. Apical (Correct Answer)
B. Apicolateral
C. Basal
D. Basolateral

Explanation: ***Apical*** - **Tight junctions** (Zonula Occludens) are the most **apical** component of the junctional complex in many epithelial cells [1]. - Their primary function is to seal adjacent cells, preventing the passage of molecules between them (paracellular route), thus establishing **epithelial polarity** [1], [2]. *Apicolateral* - This term is less precise; the junctional complex includes the tight junction (**apical**), followed by the adherens junction, and then the desmosome (**lateral**). - The tight junction itself is specifically located at the very **apical** edge, not spanning the entire apicolateral domain [1]. *Basal* - The **basal** part of the cell is where the cell attaches to the **basement membrane** via structures like hemidesmosomes [1]. - Tight junctions are not found here, as they are essential for defining the **apical** vs. basolateral domains. *Basolateral* - The **basolateral** domain comprises the sides and base of the cell, where structures like **desmosomes** (lateral) and hemidesmosomes (basal) are found [1]. - This region is separated from the lumen by the function of the **tight junction** located upstream at the apical pole [2].

Question 4: A middle-aged lady choked while eating fish and has associated symptoms of coughing, hoarseness of voice, and a foreign body sensation in the throat. On examination, the pyriform fossa is found to be inflamed. Which of the following nerves supplies this region?

A. External Laryngeal Nerve (ELN)
B. Glossopharyngeal Nerve
C. Recurrent Laryngeal Nerve
D. Internal Laryngeal Nerve (ILN) (Correct Answer)

Explanation: ***Internal Laryngeal Nerve (ILN)*** - The **Internal Laryngeal Nerve** (sensory branch of **superior laryngeal nerve**, CN X) provides **sensory innervation to the pyriform fossa** and surrounding hypopharyngeal structures. - Fish bone impaction in the pyriform fossa irritates the **ILN**, causing **cough reflex**, **hoarseness**, and **foreign body sensation** as described in this case. *External Laryngeal Nerve (ELN)* - The **External Laryngeal Nerve** is primarily a **motor nerve** that supplies the **cricothyroid muscle** for vocal cord tensioning. - It provides **minimal sensory contribution** and does not innervate the mucosa of the pyriform fossa. *Glossopharyngeal Nerve* - The **Glossopharyngeal Nerve (CN IX)** provides sensory innervation to the **oropharynx** and **posterior third of tongue**, not the pyriform fossa. - The pyriform fossa is anatomically part of the **hypopharynx (laryngopharynx)**, which is supplied by branches of the **vagus nerve**, not CN IX. *Recurrent Laryngeal Nerve* - The **Recurrent Laryngeal Nerve** primarily provides **motor innervation** to intrinsic laryngeal muscles (except cricothyroid). - Its sensory distribution is limited to the **infraglottic larynx** (below vocal cords), not the pyriform fossa region.

Question 5: Which of the following nerves gives sensory supply to the orbit?

A. Trigeminal nerve (Correct Answer)
B. Hypoglossal nerve
C. Oculomotor nerve
D. Vagus nerve

Explanation: ***Trigeminal nerve*** - The **Ophthalmic division (V1)** of the Trigeminal nerve (CN V) is the primary source of general sensation for structures within the orbit, including the globe, conjunctiva, and lacrimal gland. - Its key branches, which include the **frontal**, **lacrimal**, and **nasociliary nerves**, are responsible for carrying these sensory fibers. *Vagus nerve* - The Vagus nerve (CN X) is primarily involved in **parasympathetic control** of the thoracic and abdominal viscera, and motor supply to the pharynx and larynx. - It does not supply the orbit with any **general sensory** fibers; its distribution is mainly to the neck, chest, and abdomen. *Hypoglossal nerve* - The Hypoglossal nerve (CN XII) is a purely **somatic motor nerve** originating from the medulla. - Its function is restricted to supplying the **intrinsic and extrinsic muscles of the tongue**, having no role in orbital innervation or sensation. *Oculomotor nerve* - The Oculomotor nerve (CN III) is predominantly a **motor nerve** that supplies four of the six extraocular muscles and the **Levator palpebrae superioris**. - While it carries **parasympathetic fibers** to the ciliary ganglion, it does not provide **general sensory** supply to the orbital structures.

Question 6: Out of the following, which statements are correct? 1. Epidermis can regenerate from hair bulbs and sebaceous glands 2. Stratum corneum is the outermost cellular layer 3. Epidermis originates from the ectoderm 4. Dermis and hypodermis originate from the endoderm

A. 3,4
B. 1,2
C. 2,3
D. 1,3 (Correct Answer)

Explanation: ***Correct Option: 1,3*** - **Statement 1 is correct:** Deep injuries or burns destroy the interfollicular epidermis, and regeneration must occur from stem cells found in the **adnexal structures**, primarily the **hair follicle bulge** [1] and sweat/sebaceous glands [2]. - **Statement 3 is correct:** The epidermis, being the outer epithelial layer, is derived embryologically from the **surface ectoderm**. *Incorrect Option: 1,2* - Statement 1 is correct. However, Statement 2 is incorrect because the **stratum corneum** is the outermost layer composed of **dead, anucleated keratinocytes** (corneocytes) [2], making it an acellular/non-cellular barrier, not the outermost cellular layer. - The outermost true cellular (viable) layer is the stratum granulosum. *Incorrect Option: 2,3* - Statement 2 is incorrect because the stratum corneum is composed of **dead cells** forming a protective layer; it is not considered a viable cellular layer [2]. - Statement 3 is correct, confirming the derivation of the epidermis from the **surface ectoderm**. *Incorrect Option: 3,4* - Statement 3 is correct. However, Statement 4 is incorrect because the connective tissue layers—the **dermis** and the **hypodermis**—are derived from the embryonic **mesoderm** (specifically the dermatome component of the somites), not the endoderm.

Question 7: The dental numbering system shown below represents: R 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 (permanent teeth) and R e d c b a | a b c d e (deciduous teeth) for upper and lower quadrants. Which dental numbering system is this?

A. FDI formula
B. Universal system
C. Palmer's notation (Correct Answer)
D. Haderup system

Explanation: ***Palmer's notation*** - This system, also known as the **Zsigmondy-Palmer notation**, utilizes numerical digits (1-8) for permanent teeth and lower-case letters (a-e) for deciduous teeth within each quadrant. - The defining characteristic shown is the use of a **quadrant symbol (or grid symbols)** to indicate the location relative to the midline and the occlusal plane (e.g., $\text{8}\rfloor$ for upper right third molar). ***Universal system*** - This system uses a continuous sequence of numbers (1-32) for permanent teeth starting from the **Maxillary Right Third Molar (tooth 1)** and proceeding clockwise. - It does not use quadrant diagrams or grid lines; deciduous teeth are designated using capitalized letters A through T. ***FDI formula*** - The FDI system (ISO 3950) is a **two-digit numbering system** where the first digit identifies the quadrant (1-4 for permanent; 5-8 for deciduous) and the second digit identifies the tooth type (1-8). - For example, the upper right central incisor is denoted as **11**, which is different from the single digit representation shown. ***Haderup system*** - This system uses positive (+) or negative (-) signs to indicate the jaw (maxilla/mandible) alongside the tooth number (1-8). - The sign's position relative to the number determines the side of the midline, such as $+1$ indicating the **upper right central incisor**.

Question 8: Identify the structure labeled in the histology image shown.

A. Alveolar duct
B. Respiratory bronchiole (Correct Answer)
C. Bronchus
D. Terminal bronchiole

Explanation: ***Respiratory bronchiole*** - The key identifying feature is the presence of **alveoli** opening directly from its lumen, which is characteristic of the respiratory zone where gas exchange begins. - It represents the transition from the conducting to the respiratory portion of the airway, lined by a simple **cuboidal epithelium** with scattered cilia and club cells. *Terminal bronchiole* - A terminal bronchiole is the most distal part of the **conducting zone** and has a continuous wall without any associated alveoli. - It is lined by simple cuboidal epithelium, which includes **club cells** (formerly Clara cells), but no gas exchange occurs here. *Alveolar duct* - An alveolar duct is a tube whose walls are almost entirely composed of the openings of alveoli and alveolar sacs. - It lacks the more continuous epithelial wall seen in a respiratory bronchiole and is primarily just a passageway lined by alveolar openings. *Bronchus* - A bronchus is a larger airway characterized by the presence of **cartilage plates** or rings and **submucosal glands** in its wall, both of which are absent in the image. - It is lined by **pseudostratified ciliated columnar epithelium** containing goblet cells, which is different from the simple epithelium seen here.

Question 9: Tight junctions are primarily located at which part of the cell?

A. Apicolateral
B. Basolateral
C. Apical (Correct Answer)
D. Basal

Explanation: ***Apical*** - Tight junctions, also known as **zonula occludens**, are located at the **apical region** of polarized epithelial cells [1]. - They form the most **apical component** of the junctional complex, positioned at the apical-most part of the lateral cell membrane, just below the free apical surface [1]. - They are crucial for forming a **permeability barrier** that controls paracellular transport and maintains cell polarity by separating apical from basolateral membrane domains [2]. *Incorrect Apicolateral* - While tight junctions are technically at the interface between apical and lateral domains, "apicolateral" is **not standard anatomical terminology** used in medical textbooks. - The standard anatomical description places tight junctions at the **apical region** of epithelial cells. *Incorrect Basolateral* - The **basolateral domain** encompasses the lateral cell membrane (where adhesion junctions like desmosomes and communication junctions like gap junctions are located) and the basal membrane. - Tight junctions are positioned **above** these other junctional complexes, at the apical-most position [1]. *Incorrect Basal* - The basal surface rests on the **basement membrane**. - The characteristic junction here is the **hemidesmosome**, which anchors the cell to the underlying extracellular matrix, not to seal adjacent cells [1].

Question 10: Match the cardiac anatomical features from Column I with their corresponding labels from Column II. Column I: 1. Receives oxygenated blood from pulmonary veins; 2. Lies anterior to ascending aorta; 3. Arises from LV; 4. Hypertrophy in pulmonary stenosis. Column II: A. Ascending aorta; B. Right ventricle; C. Pulmonary trunk; D. Left atrium.

A. 1-D, 2-C, 3-A, 4-B (Correct Answer)
B. 1-A, 2-B, 3-C, 4-D
C. 1-B, 2-D, 3-C, 4-A
D. 1-C, 2-A, 3-D, 4-B

Explanation: 1-D, 2-C, 3-A, 4-B - 1-D (Receives oxygenated blood): The left atrium receives four pulmonary veins carrying oxygenated blood from the lungs [1], making it the only chamber that receives oxygenated blood directly from pulmonary circulation. - 2-C (Lies anterior to ascending aorta): The pulmonary trunk is positioned anteriorly and slightly to the left of the ascending aorta as both vessels exit from the base of the heart. - 3-A (Arises from LV): The ascending aorta arises directly from the left ventricle through the aortic valve and is the major systemic artery carrying oxygenated blood to the body. - 4-B (Hypertrophy in pulmonary stenosis): Pulmonary stenosis increases resistance to right ventricular outflow, causing chronic pressure overload and subsequent right ventricular hypertrophy. 1-A, 2-B, 3-C, 4-D - This matching is incorrect because the ascending aorta (A) does not receive blood from pulmonary veins [1]; it arises from the LV and carries blood away from the heart. Additionally, the pulmonary trunk (C) arises from the right ventricle, not the left ventricle. 1-B, 2-D, 3-C, 4-A - This matching is incorrect because the right ventricle (B) receives deoxygenated blood from the right atrium via the vena cavae, not oxygenated blood from pulmonary veins [1]. The left atrium (D) is a posterior chamber and does not lie anterior to the ascending aorta. 1-C, 2-A, 3-D, 4-B - This matching is incorrect because the pulmonary trunk (C) carries deoxygenated blood to the lungs; it does not receive oxygenated blood from pulmonary veins [1]. The left atrium (D) is not a vessel that arises from the LV—the correct structure is the ascending aorta (A).