INI-CET 2018 - Anatomy Practice Questions

Q: Which of the following structures of the scapula is palpable in infraclavicular fossa?

C. ***C - Coracoid Process*** - The **coracoid process** is a hook-like bony projection from the superior border of the scapula that extends anteriorly and laterally. - It is located approximately **2.5 cm below the lateral third of the clavicle** in the **infraclavicular fossa** (also called the deltopectoral triangle). - The coracoid process is the **only structure of the scapula that is palpable anteriorly** in the infraclavicular fossa, making it an important surgical landmark. - It can be felt by deep palpation in the infraclavicular region, just medial to the deltoid muscle. *A - Glenoid Cavity* - The glenoid cavity is the shallow, pear-shaped articular surface on the lateral angle of the scapula that receives the head of the humerus. - It is deeply positioned and completely covered by the humeral head and surrounding soft tissues (rotator cuff muscles, joint capsule). - It is **not palpable** from any surface location, including the infraclavicular fossa. *B - Acromion* - The acromion is the lateral continuation of the spine of the scapula, forming the highest point of the shoulder. - It articulates with the lateral end of the clavicle at the acromioclavicular joint. - The acromion is palpable at the **tip of the shoulder laterally**, not in the infraclavicular fossa which is located more medially and anteriorly. - It forms part of the superior boundary of the shoulder region, well lateral to the infraclavicular fossa. *D - Inferior Angle of Scapula* - The inferior angle is the lowest point of the scapula, located at approximately the level of the 7th rib or T7 vertebra. - It is palpable on the **posterior thoracic wall**, particularly when the arm is moved. - It is located posteriorly and inferiorly, nowhere near the anterior infraclavicular fossa.

Q: Mandibular division of trigeminal nerve passes through which of the following? (AIIMS May 2018)

D. ***D*** - The label 'D' points to the **foramen ovale**, which is the opening through which the **mandibular division of the trigeminal nerve (V3)** exits the middle cranial fossa. - The foramen ovale also transmits the **accessory meningeal artery**, **lesser petrosal nerve**, and the **emissary veins**. *A* - The label 'A' points to the **foramen rotundum**, which is primarily for the passage of the **maxillary division of the trigeminal nerve (V2)**. - The foramen rotundum is distinct from the foramen ovale and is located more anterior and medial. *B* - The label 'B' points to the **foramen spinosum**, which allows the passage of the **middle meningeal artery** and the **nervus spinosus (meningeal branch of V3)**. - While it transmits a branch of V3, it is not the main exit point for the entire mandibular division. *C* - The label 'C' points to the **foramen lacerum**, which is occupied by **cartilage** in vivo and primarily traversed by the **internal carotid artery** and its accompanying sympathetic plexus passing superiorly to it. - No major cranial nerves pass completely through it; instead, some nerves (like the greater petrosal nerve) pass over its superior surface or exit through associated canals.

Q: Which disease occurs due to involvement of the structure marked in red? (AIIMS May 2018)

Paralysis agitans. ***Paralysis agitans*** - The red circle points to the **substantia nigra**, a key brain structure involved in producing **dopamine**. - **Paralysis agitans**, also known as **Parkinson's disease**, is characterized by the degeneration of dopaminergic neurons in the substantia nigra, leading to motor symptoms like tremor, rigidity, and bradykinesia. *Depression* - Depression is a mood disorder associated with imbalances in various **neurotransmitters** (e.g., serotonin, norepinephrine, dopamine) and often involves brain regions such as the prefrontal cortex and limbic system, not primarily the substantia nigra. - While dopamine pathways can be implicated in motivation and reward, the primary pathology of major depression is not direct degeneration of the substantia nigra. *Alzheimer's disease* - Alzheimer's disease is a neurodegenerative disorder primarily characterized by the accumulation of **amyloid plaques** and **neurofibrillary tangles**, leading to neuronal loss and brain atrophy, particularly in the hippocampus and cerebral cortex, not the substantia nigra. - It results in progressive **memory loss** and cognitive decline, distinct from the motor symptoms seen in Parkinson's. *Huntington's chorea* - Huntington's chorea is a hereditary neurodegenerative disease caused by the degeneration of GABAergic neurons in the **striatum** (caudate and putamen). - It is characterized by **involuntary movements** (chorea), cognitive decline, and psychiatric symptoms, which result from basal ganglia dysfunction but not specifically originating from the substantia nigra.

Q: The marked extraocular muscle has a cranial nerve nucleus. At what level in the brain is the nucleus located? (AIIMS May 2018)

Facial colliculus. ***Facial colliculus*** - The image shows the **lateral rectus muscle** (indicated by the arrow), which controls abduction of the eye. - The lateral rectus muscle is innervated by the **abducens nerve (CN VI)**, and its nucleus is located at the **facial colliculus** in the pons. - The facial colliculus is a bulge on the dorsal surface of the pons, formed by the **facial nerve (CN VII) fibers** wrapping around the **abducens nucleus (CN VI)**. - This is the only extraocular muscle whose nucleus is located at the facial colliculus. *Superior colliculus* - The superior colliculus is located in the **midbrain** and is involved in visual reflexes and saccadic eye movements. - The **oculomotor nucleus (CN III)** is located ventral to the superior colliculus in the periaqueductal gray at the level of the superior colliculus. - CN III innervates the superior rectus, inferior rectus, medial rectus, and inferior oblique muscles, but not the muscle shown in the image. *Superior olivary nucleus* - The superior olivary nucleus is located in the **pons** and is a critical component of the auditory pathway, involved in sound localization. - It has no role in the innervation of extraocular muscles. *Inferior colliculus* - The inferior colliculus is situated in the **midbrain** and is a major relay center in the auditory pathway. - The **trochlear nucleus (CN IV)** is located at the level of the inferior colliculus and innervates the superior oblique muscle. - However, the inferior colliculus itself does not contain nuclei for extraocular muscle innervation.

Q: What is the function of the muscle marked in the cut section shown below? (AIIMS May 2018)

Depression. ***Depression*** - The image shows the **lateral pterygoid muscle** in a transverse section of the head. The **inferior head** of this muscle assists in **mandibular depression** (mouth opening) when both sides contract together. - While the **primary functions** of the lateral pterygoid are **protrusion** and **lateral excursion** of the mandible, among the given options, **depression is the only function this muscle actually performs**. - The lateral pterygoid does **NOT perform elevation or retraction**, making depression the **only anatomically correct answer** from the choices provided. *Elevation* - The lateral pterygoid muscle does **NOT elevate** the mandible - this is anatomically incorrect. - **Primary elevators** of the mandible are the **masseter**, **temporalis**, and **medial pterygoid muscles** (all supplied by the mandibular division of the trigeminal nerve). *Retraction* - The lateral pterygoid muscle does **NOT retract** the mandible - it actually **protrudes** it, which is the **opposite of retraction**. - **Mandibular retraction** is primarily performed by the **posterior fibers of the temporalis muscle** and the **deep fibers of the masseter**. *All of the above* - This option is incorrect because the lateral pterygoid does **NOT perform elevation or retraction**. - The muscle's **primary functions** are **protrusion** (forward movement) and **lateral excursion** (side-to-side movement), with **assistive role in depression** (mouth opening) when both inferior heads contract simultaneously.

Q: Which structure passes through the area marked in red? (AIIMS May 2018)

Vertebral artery. ***Vertebral artery*** - The image displays a cervical vertebra, and the red-marked area highlights the **foramen transversarium** (or transverse foramen). This foramen is a defining feature of cervical vertebrae. - The **vertebral artery** ascends through these foramina in cervical vertebrae C1-C6, providing blood supply to the brain. *Anterior inferior cerebellar artery* - The **anterior inferior cerebellar artery (AICA)** is a branch of the basilar artery and supplies parts of the cerebellum and brainstem. - It is an **intracranial vessel** and does not pass through the foramina transversaria of the cervical vertebrae. *Transverse ligament* - The **transverse ligament of the atlas** is a crucial ligament that holds the dens of the axis against the anterior arch of the atlas. - It is located **within the vertebral canal**, posterior to the dens, not within the foramen transversarium of the transverse process. *Apical ligament* - The **apical ligament** connects the apex of the dens (odontoid process) of C2 (axis) to the anterior margin of the foramen magnum. - Like the transverse ligament, it is an **intracranial ligament** associated with the craniocervical junction, not a structure passing through the foramen transversarium.

Q: Which structure is marked with a red arrow in the image shown below? (AIIMS May 2018)

Mammillary bodies. ***Mammillary bodies*** - The image shows an **axial view** of the brain, and the red arrow points to a rounded structure anterior to the pons, consistent with the location of the **mammillary bodies**. - These are part of the **limbic system** and play a crucial role in memory formation through their connections with the hippocampus and thalamus. *Hippocampus* - The hippocampus is located in the **medial temporal lobe**, deeper and more posterior than the structure indicated by the arrow on this axial slice. - It has a characteristic elongated, curved shape, quite distinct from the **paired, rounded structures** shown. *Habenular nuclei* - The **habenular nuclei** are located in the **epithalamus**, superior to the midbrain and posterior to the thalamus, not in the anterior brainstem region indicated. - They are much smaller and are involved in modulating various brain circuits, including those related to pain, stress, and reward. *Amygdala* - The amygdala is an **almond-shaped structure** located deep within the temporal lobe, anterior to the hippocampus. - While close to the region shown, its shape and exact position differ from the **mammillary bodies**, particularly in this axial plane where the mammillary bodies are seen as distinct, round structures near the midline.

Q: Identify the structure that forms the superior border of the epiploic foramen (marked in red) in the image below.

Caudate lobe. ***Caudate lobe*** - The **caudate process of the caudate lobe** of the liver forms the **superior boundary** of the epiploic foramen (foramen of Winslow). - This is a consistent anatomical landmark that defines the **upper margin** of this important communication between the greater and lesser sacs of the peritoneal cavity. - The caudate lobe lies superior to the foramen and posterior to the lesser omentum. *Lesser omentum* - The **hepatoduodenal ligament**, which is the free edge of the lesser omentum containing the **portal triad** (portal vein, hepatic artery, and common bile duct), forms the **anterior boundary** of the epiploic foramen, not the superior border. - The lesser omentum extends from the lesser curvature of the stomach to the liver, and its free right edge creates the anterior margin of the foramen. *Duodenum* - The **first part of the duodenum** (superior/horizontal part) forms the **inferior boundary** of the epiploic foramen. - It lies below the foramen and helps define the **lower margin** of this anatomical opening. *IVC* - The **inferior vena cava (IVC)** forms the **posterior boundary** of the epiploic foramen as it ascends toward the diaphragm covered by peritoneum. - The IVC runs behind the foramen and does not contribute to the superior border of the structure.

Q: Which of the following marks the conjoint tendon?

A. ***A*** - Label **A** points to the **conjoint tendon**, which is formed by the conjoined aponeuroses of the **internal oblique** and **transversus abdominis** muscles as they insert onto the pubic crest and pecten pubis. - This structure is clinically important as it forms part of the **posterior wall of the inguinal canal** and helps prevent direct inguinal hernias. *B* - Label **B** points to the **rectus abdominis muscle**, which is one of the anterior abdominal wall muscles. - While it's an important abdominal muscle, it does not constitute the conjoint tendon. *C* - Label **C** points to the **pubic bone**, specifically indicating the general area of the pubic symphysis or body. - This is a bony landmark, not a tendon or muscular structure. *D* - Label **D** points to the **inguinal ligament**, which runs from the anterior superior iliac spine to the pubic tubercle. - The inguinal ligament forms the **inferior boundary of the inguinal canal**, whereas the conjoint tendon contributes to the posterior wall.

Q: Identify the urogenital diaphragm in the image given below:

A. ***A*** - Label **A** correctly identifies the **urogenital diaphragm**, which is positioned **inferior to the pelvic diaphragm** and forms the middle layer of the perineum. - It consists of the **deep transverse perineal muscle** and **sphincter urethrae muscle**, enclosed between **superior and inferior fascial layers**. *B* - Label **B** points to the **ischioanal fossa**, a **fat-filled space** located lateral to the anal canal, not the urogenital diaphragm. - This fossa allows for **anal canal distension** during defecation and contains vessels and nerves supplying the anal region. *C* - Label **C** indicates the **levator ani muscle**, which forms the main component of the **pelvic diaphragm**, positioned **superior** to the urogenital diaphragm. - The **pelvic diaphragm** supports pelvic organs and maintains continence, but is anatomically distinct from the urogenital diaphragm. *D* - Label **D** shows neurovascular structures within the **pudendal canal (Alcock's canal)**, containing the **pudendal nerve** and internal pudendal vessels. - This canal runs along the **lateral wall of the ischioanal fossa** and is not part of the urogenital diaphragm structure.

Question 1

Which of the following structures of the scapula is palpable in infraclavicular fossa?

Accepted Answer

C

Answer

A

Answer

B

Answer

D

Question 2

Mandibular division of trigeminal nerve passes through which of the following? (AIIMS May 2018)

Accepted Answer

D

Answer

A

Answer

B

Answer

C

Question 3

Which disease occurs due to involvement of the structure marked in red? (AIIMS May 2018)

Accepted Answer

Paralysis agitans

Answer

Depression

Answer

Alzheimer's disease

Answer

Huntington's chorea

Question 4

The marked extraocular muscle has a cranial nerve nucleus. At what level in the brain is the nucleus located? (AIIMS May 2018)

Accepted Answer

Facial colliculus

Answer

Superior colliculus

Answer

Superior olivary nucleus

Answer

Inferior colliculus

Question 5

What is the function of the muscle marked in the cut section shown below? (AIIMS May 2018)

Accepted Answer

Depression

Answer

Elevation

Answer

Retraction

Answer

All of the above

Question 6

Which structure passes through the area marked in red? (AIIMS May 2018)

Accepted Answer

Vertebral artery

Answer

Anterior inferior cerebellar artery

Answer

Transverse ligament

Answer

Apical ligament

Question 7

Which structure is marked with a red arrow in the image shown below? (AIIMS May 2018)

Accepted Answer

Mammillary bodies

Answer

Hippocampus

Answer

Habenular

Answer

Amygdala

Question 8

Identify the structure that forms the superior border of the epiploic foramen (marked in red) in the image below.

Accepted Answer

Caudate lobe

Answer

Lesser omentum

Answer

Duodenum

Answer

IVC

Question 9

Which of the following marks the conjoint tendon?

Accepted Answer

A

Answer

B

Answer

C

Answer

D

Question 10

Identify the urogenital diaphragm in the image given below:

Accepted Answer

A

Answer

B

Answer

C

Answer

D

INI-CET 2018 — Anatomy