📚 Question Bank

The given image shows the skull of an infant and the arrow points towards the anterior fontanelle.

The procedure of collecting CSF from the anterior fontanelle is called ventricular tapping. The various structures pierced are the scalp, dura, and arachnoid.

A fontanelle tap or percutaneous ventricular puncture is performed in infants without access to a VP shunt, who require urgent ventricular decompression and have an open anterior fontanelle. The layers pierced in order are: Skin, Connective tissue, Aponeurosis, Loose areolar tissue, Pericranium, Dura mater, and Arachnoid membrane.

The given image is a cadaveric specimen with the arrow pointing towards the tonsillar fossa, and the given clinical vignette is suggestive of tonsillitis.

Post tonsillectomy hemorrhage is commonly venous in origin, from the paratonsillar / external palatine vein. Torrential hemorrhage can be due to injury to an aberrantly large or aberrantly placed tonsillar arterial branch of the facial artery.

The muscle marked in the given CT image is that of the medial rectus.

The medial rectus is supplied by the oculomotor nerve, the nucleus of which is situated at the level of the superior colliculus close to the red nucleus.

The nuclear complex from which the oculomotor nerve arises consists of motor neurons (supplying inferior rectus, inferior oblique, medial rectus, and contralateral superior rectus) and Edinger–Westphal preganglionic nucleus.

The branches from the anterior division include 2, 3, 4, 5, 6.

Branches of the anterior trunk of the internal iliac artery include: Obturator artery, Superior vesical artery, Inferior vesical artery, Inferior gluteal artery, Middle rectal artery, Vaginal artery (in females), Uterine artery (in females), and Internal pudendal artery.

Branches of the posterior trunk include: Iliolumbar artery, Lateral sacral arteries, and Superior gluteal artery.

The peduncle highlighted in the image is the superior cerebellar peduncle. The superior cerebellar peduncle includes fibers from deep cerebellar nuclei that project to the brainstem, red nucleus, and thalamus. It also contains the ventral spinocerebellar tract fibers.

The superior cerebellar peduncle contains all the efferent fibers from the dentate, emboliform, and the globose nuclei, and a small fascicle from the fastigial nucleus. Its fibers decussate in the caudal mesencephalon and are destined to synapse in the contralateral red nucleus and thalamus. The middle cerebellar peduncle contains only afferent fibers from the contralateral pontine nuclei. The inferior cerebellar peduncle is a mixture of afferent fibers from the brainstem and spinal cord and efferent fibers to the vestibular nuclei.

The image below summarizes the various tracts in the cerebellar unit.

The cerebellum consists of two hemispheres (right and left) joined by a median vermis. It is divided into three lobes:-

• Anterior lobe - lies superiorly above the primary fissure
• Middle lobe - lies inferiorly below the primary fissure. It is the largest lobe. It is also
• called the posterior lobe.
• Flocculonodular lobe - lies posterior to the uvulonodular fissure

It has two surfaces - superior and inferior separated by a horizontal fissure. It is connected to the other parts of the central nervous system via three peduncles

• Superior cerebellar peduncle -connecting to the midbrain
• Middle cerebellar peduncle - connecting to the pons
• Inferior cerebellar peduncle - connecting to the medulla oblongata

The given clinical stem of a hemi-sensory loss and severe excruciating pain of the affected areas is suggestive of thalamic pain syndrome also known as Dejerine Roussy

syndrome. Hence, thalamus marked as B is most likely to be involved.

Occlusion of these thalamic and thalamogeniculate branches results in the thalamic pain syndrome. It is characterized by C/L hemisensory loss which starts as numbness and progresses to cause severe burning pain in the affected regions. As the thalamus is the site for the relay of sensory information between the periphery and cortex, a lesion in the thalamus causes a miscommunication between the afferent pathway and cortex of the brain. Pain occurs during the recovery from the thalamic infarct. This pain responds poorly to analgesics. Anticonvulsants such as carbamazepine or gabapentin or tricyclic antidepressants may be beneficial.

Other markings:

A: Caudate nucleus C: Substantia nigra D: Pons

The image below shows the coronal section of the brain with different parts of the basal ganglia:

The likely site of injury is the medial epicondyle (C).

This clinical presentation indicates ulnar nerve palsy. The ulnar nerve is highly susceptible to injury behind the medial epicondyle of the humerus, leading to clawing of the 4th and 5th digits and an inability to adduct the fingers (positive card test).

The image shows pharyngeal pouches and based on the clinical history, the patient most likely has DiGeorge syndrome (thymic and parathyroid defects). It is caused by defective development of the third and fourth pharyngeal pouch.

In the given stem, it is mentioned that the thymus is absent. The thymus derives from the 3rd pharyngeal pouch, so the correct option is 3.

The given clinical vignette is suggestive of injury to the axillary nerve which leads to deltoid muscle palsy.

The axillary nerve supplies the deltoid muscle. Iatrogenic injuries of the axillary nerve can occur due to incorrectly administered IM injections (like a vaccine). Injury leads to weakness of abduction, atrophy of the Deltoid muscle (loss of shoulder contours), and loss of sensation in the Regimental badge area.

The structure marked in the given image is the epiploic foramen (foramen of Winslow).

The superior border of the epiploic foramen is formed by the caudate lobe of the liver. It connects the lesser sac to the greater sac.

• Anterior: Free margin of lesser omentum (containing portal vein, hepatic artery, bile duct)
• Posterior: Inferior Vena Cava
• Inferior: 1st part of duodenum

The given image shows various skull foramina.

Infection through the cribriform plate and olfactory bulb (marked A) and dissemination through trans-synaptic transfer are mechanisms proposed for the SARS-COV2 virus to reach the brain. This can lead to neurological sequelae like encephalitis, demyelination, or refractory respiratory failure.

The structure involved in causing lurching gait in the child is the gluteus medius (marked as 2).

The gluteus medius originates from the outer surface of the ilium and inserts at the lateral surface of the greater trochanter. It is supplied by the superior gluteal nerve. Gluteus medius and minimus are powerful abductors of the hip joint. Their paralysis leads to a positive Trendelenburg's sign with a characteristic lurching gait.

The given clinical scenario is suggestive of the involvement of the 9th and 10th cranial nerves due to occipitotemporal fracture.

These are examined by testing the uvula which is marked as 2 in the given image. The jugular foramen is located between the lower border of the petrous part of the temporal bone and the condylar part of the occipital bone. Unilateral lesions lead to dysphagia, weakness of soft palate, and deviation of the uvula to the normal side.

The structure marked in the above image is the mamillary body and the fibers from the mamillary body end in the anterior nucleus of the thalamus via the mamillothalamic tract.

The mammillary bodies are two small hemispherical eminences forming the floor of the third ventricle. The anterior thalamic nucleus functions in the regulation of alertness, attention, and acquisition of memory.

The structure marked in the image is a flask-shaped neuron in the cerebellar cortex, which is a Purkinje cell.

It is inhibitory to deep cerebellar nuclei and uses GABA as its neurotransmitter. Axons of Purkinje cells are the only efferents of the cerebellar cortex.

The structure marked in the given image is the azygos vein, which develops from the supracardinal vein embryologically.

The azygos system forms a connecting channel between the superior and inferior venae cavae. The right supracardinal vein becomes the azygos vein, while the left supracardinal vein becomes the hemiazygos vein.

All the given 4 structures (Pharynx, Trachea, Oesophagus, Thyroid gland) are supplied by the Inferior thyroid artery.

Inferior thyroid artery is a branch of the thyrocervical trunk, which in turn is a branch of the first part of the subclavian artery. It gives off pharyngeal branches, tracheal branches, oesophageal branches, inferior and ascending glandular branches (for thyroid/parathyroid), and inferior laryngeal branches.

The part of the scapula marked as 1 is the coracoid process and it is palpable in the infraclavicular fossa.

The tip of the coracoid process lies approximately 2.5 cm below the clavicle, immediately lateral to the infraclavicular fossa (deltopectoral triangle). It projects forwards and slightly laterally from the upper border of the neck of the scapula.

Among the given options, Option B represents an incorrect match, as the structure labeled as 4 is showing the basement membrane and not lamina propria.

The given image is of pseudostratified ciliated columnar epithelium. It shows cilia (1), goblet cells (2), and nuclei at different levels (3), all attached to the basement membrane (4).

The third part of the vertebral artery (V3) is related to the area marked 2, which is the posterior arch of the first cervical vertebra or the atlas.

The superior surface of the posterior arch bears a groove for the vertebral artery and venous plexus immediately behind the lateral mass. The vertebral artery lies in this groove within the suboccipital triangle before entering the foramen magnum.

The bone marked in the above image is the left clavicle. The most common complication of a central line insertion (subclavian vein catheterization) below this bone is an arterial puncture (subclavian artery).

Other complications include pneumothorax, cardiac tamponade, chylothorax, and nerve injury.

In the given image, the dorsal aspect of the brainstem is marked and the cranial nerve that is passing there is the trochlear nerve (CN IV).

It is the only cranial nerve that emerges from the dorsal surface of the brainstem. It originates from the midbrain at the level of the inferior colliculus, decussates, and exclusively supplies the contralateral superior oblique muscle.

An aneurysm of the anterior communicating artery is most likely to be causing damage to the optic chiasma, leading to vision loss in this patient.

Circle of Willis is a large arterial anastomosis that unites the internal carotid and vertebrobasilar systems. It lies in the subarachnoid space within the basal cisterns that surround the optic chiasma and infundibulum. The anterior communicating artery (Acom) links the right and left anterior cerebral arteries and is directed anterior and superior to the optic chiasma. The aneurysm will protrude in the posterior direction and will impinge upon the optic chiasma from above, leading to loss of vision.

The vertical and downward descent of the spleen is prevented by the phrenicocolic ligament.

The phrenicocolic ligament is not attached to the spleen. It attaches the splenic flexure of the colon to the diaphragm. When the spleen gets enlarged, the phrenicocolic ligament along with the splenic flexure of the colon restricts its downward displacement. The enlargement of the spleen occurs towards the right iliac fossa and hence the spleen is directed obliquely.

The given histological image is a section of the tongue showing circumvallate papillae, which are the largest papillae of the tongue.

They are dome-shaped structures located just anterior to the sulcus terminalis and are surrounded by a moat-like invagination. Taste buds are present on their lateral surfaces.