INI-CET 2018 Practice Questions

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.

Q: In the given slide of cerebellum, the marked cell is inhibitory to?

Deep nuclei of cerebellum. ***Deep nuclei of cerebellum*** - The image shows a **Purkinje cell** (large, flask-shaped neuron with a prominent nucleolus, indicated by the arrow) located in the cerebellum. - Purkinje cells are the sole output neurons of the cerebellar cortex and exert an **inhibitory (GABAergic)** effect primarily on the **deep cerebellar nuclei.** *Vestibular nuclei* - While Purkinje cells of the **flocculonodular lobe and vermis** project to the vestibular nuclei, the primary and most direct inhibitory target discussed in the general context of Purkinje cell output are the deep cerebellar nuclei. - The Vestibular nuclei receive input from the cerebellum, but are not the sole or primary direct targets of all Purkinje cells. *Anterior horn of spinal cord* - The anterior horn of the spinal cord contains **motor neurons** and interneurons involved in motor control, but it does not receive direct innervation from Purkinje cells. - Cerebellar output influences spinal cord activity indirectly via relays in the brainstem and other motor control centers. *Basal ganglia* - The basal ganglia are subcortical nuclei involved in motor control and learning, forming a distinct neural circuit separate from the cerebellum. - There are **no direct inhibitory projections** from cerebellar Purkinje cells to the basal ganglia.

Q: This diagnosis is?

Scaphoid fracture. ***Scaphoid fracture*** - Classic mechanism of **fall on outstretched hand (FOOSH)** with forced **dorsiflexion** of wrist, commonly affecting the **scaphoid waist**. - Clinical presentation includes **anatomical snuffbox tenderness** and pain with **axial loading** of thumb and **scaphoid compression test**. *Rheumatoid arthritis* - Systemic autoimmune condition affecting **multiple joints symmetrically**, not typically presenting as acute wrist trauma. - Characterized by **morning stiffness**, **synovial swelling**, and **positive rheumatoid factor** rather than focal bone fracture. *Scapholunate dissociation* - Results in **widening of scapholunate interval** on X-ray (>3mm) and **Terry Thomas sign** on PA view. - Presents with **dorsal wrist pain** and **Watson's test positivity** but lacks the specific fracture line seen in scaphoid injury. *Lunate dislocation* - Shows characteristic **spilled teacup sign** on lateral X-ray with **lunate tilted volarly** and loss of normal carpal alignment. - Presents as **severe wrist deformity** with **median nerve compression symptoms** rather than localized scaphoid area tenderness.

Q: In the image shown below, which of the marked area is involved in relieving pain in response to massage?

Area A. ***A*** - Area A points to the **dorsal columns** (specifically the fasciculus gracilis and cuneatus) of the spinal cord, which carry **mechanoreceptive** and proprioceptive information. - Massage activates large diameter afferent fibers which transmit signals via the dorsal columns, inhibiting pain transmission through the **gate control theory of pain**. *B* - Area B points to the **dorsal horn** (specifically lamina I, II, and V), which is primarily involved in receiving and processing **nociceptive input**. - While integration of pain occurs here, it is not the primary pathway for the **modulatory effects of touch/pressure** from massage for pain relief. *C* - Area C indicates the **ventral horn** of the spinal cord, which contains **motor neurons** that control skeletal muscle activity. - It is involved in motor output, not directly in the sensory processing or modulation of pain signals from massage. *D* - Area D points to the **lateral white matter**, which contains various ascending and descending tracts, including the **spinothalamic tract** (primary pain pathway) and corticospinal tract. - While the spinothalamic tract carries pain signals, the direct pain-relieving effect of massage primarily involves activation of mechanoreceptors whose signals ascend via the dorsal columns.

Question 1

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 2

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 3

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 4

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 5

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 6

Which of the following marks the conjoint tendon?

Accepted Answer

A

Answer

B

Answer

C

Answer

D

Question 7

Identify the urogenital diaphragm in the image given below:

Accepted Answer

A

Answer

B

Answer

C

Answer

D

Question 8

In the given slide of cerebellum, the marked cell is inhibitory to?

Accepted Answer

Deep nuclei of cerebellum

Answer

Vestibular nuclei

Answer

Anterior horn of spinal cord

Answer

Basal ganglia

Question 9

This diagnosis is?

Accepted Answer

Scaphoid fracture

Answer

Rheumatoid arthritis

Answer

Scapholunate dissociation

Answer

Lunate dislocation

Question 10

In the image shown below, which of the marked area is involved in relieving pain in response to massage?

Accepted Answer

Area A

Answer

Area B

Answer

Area C

Answer

Area D

INI-CET 2018

Anatomy

Orthopaedics

Physiology