Neuroanatomy Past Paper PDF

Which of the following bones forms the anterior boundary of the anterior cranial fossa? A\) Sphenoid bone B\) Frontal bone C\) Temporal bone D\) Ethmoid bone Answer: B) Frontal bone 2. Which of the following structures does NOT pass through the foramen ovale in the middle cranial fossa?...

Which of the following bones forms the anterior boundary of the anterior cranial fossa? A\) Sphenoid bone B\) Frontal bone C\) Temporal bone D\) Ethmoid bone Answer: B) Frontal bone 2. Which of the following structures does NOT pass through the foramen ovale in the middle cranial fossa? A\) Mandibular nerve (V3) B\) Accessory meningeal artery C\) Glossopharyngeal nerve D\) Lesser petrosal nerve Answer: C) Glossopharyngeal nerve 3. A patient presents with an infection in the middle cranial fossa. Which structure is most likely involved? A. Frontal lobe B. Optic nerve C. Temporal lobe D. Cerebellum Answer: C) Temporal lobe 4. Which of the following is NOT a derivative of the hindbrain (rhombencephalon)? E. Pons F. Medulla oblongata G. Thalamus H. Cerebellum Answer: C) Thalamus 5. The alar plate of the neural tube gives rise to which of the following? I. Sensory neurons J. Motor neurons K. Interneurons L. Glial cells Answer: A) Sensory neurons 6. A neural tube defect results in a failure of differentiation of the basal plate. Which structure would be most affected? M. Spinal cord motor neurons N. Cerebellum O. Sensory neurons P. Reticular formation Answer: A) Spinal cord motor neurons Which of the following branches of the internal carotid artery supplies the anterior part of the brain? A\) Anterior cerebral artery B\) Posterior cerebral artery C\) Vertebral artery D\) Middle cerebral artery Answer: A) Anterior cerebral artery A blockage in the middle cerebral artery (MCA) could result in which of the following symptoms? A\) Hemianopia (visual field loss) B\) Hemiparesis (weakness of one side of the body) C\) Dysphasia (speech difficulty) D\) All of the above Answer: D) All of the above The Circle of Willis connects which arteries? A\) Internal carotid and vertebral arteries B\) Vertebral and basilar arteries C\) Anterior cerebral and posterior cerebral arteries D\) Internal carotid and subclavian arteries Answer: A) Internal carotid and vertebral arteries Which of the following is a function of the dural folds? A\) Cushioning the brain B\) Providing nutrients to the brain C\) Dividing the brain into functional regions D\) Protecting the brain from mechanical injury Answer: C) Dividing the brain into functional regions Arachnoid granulations are involved in which of the following processes? A\) Absorption of cerebrospinal fluid (CSF) B\) Secretion of CSF C\) Protection of the brain from infection D\) Distribution of oxygen to brain tissue Answer: A) Absorption of cerebrospinal fluid (CSF) A patient presents with a sudden headache and neck stiffness. An MRI shows a subarachnoid hemorrhage. Which meningeal space is most likely involved? A\) Epidural space B\) Subdural space C\) Subarachnoid space D\) Pia mater Answer: C) Subarachnoid space Which of the following structures is part of the third ventricle? A\) Foramen of Monro B\) Cerebral aqueduct C\) Choroid plexus D\) Corpus callosum Answer: A) Foramen of Monro The choroid plexus is responsible for the production of which of the following? A\) Blood-brain barrier B\) Cerebrospinal fluid (CSF) C\) Myelin D\) Meningeal layers Answer: B) Cerebrospinal fluid (CSF) A patient develops a blockage in the cerebral aqueduct. Which ventricle would most likely become enlarged? A\) Lateral ventricle B\) Third ventricle C\) Fourth ventricle D\) None of the above Answer: A) Lateral ventricle Which of the following cranial nerves is responsible for the sensation of taste from the anterior two-thirds of the tongue? A\) Vagus nerve (X) B\) Facial nerve (VII) C\) Glossopharyngeal nerve (IX) D\) Trigeminal nerve (V) Answer: B) Facial nerve (VII) Which cranial nerve exits the skull through the foramen ovale? A\) Abducens nerve (VI) B\) Mandibular nerve (V3) C\) Vagus nerve (X) D\) Accessory nerve (XI) Answer: B) Mandibular nerve (V3) Which of the following structures is responsible for motor control in the spinal cord? A\) Posterior horn B\) Anterior horn C\) Dorsal root ganglion D\) Spinal cord gray matter Answer: B) Anterior horn A lesion in the posterior horn of the spinal cord would most likely affect which of the following functions? A\) Motor control of limbs B\) Sensory perception, including touch and proprioception C\) Sympathetic nervous system regulation D\) None of the above Answer: B) Sensory perception, including touch and proprioception Which of the following cranial nerves emerges from the midbrain? A\) Oculomotor nerve (III) B\) Trigeminal nerve (V) C\) Facial nerve (VII) D\) Vagus nerve (X) Answer: A) Oculomotor nerve (III) A patient with a lesion in the pons might experience which of the following? A\) Paralysis of the upper limbs B\) Difficulty with facial movements C\) Loss of sensation in the lower limbs D\) Difficulty with speech and swallowing Answer: B) Difficulty with facial movements Which of the following is a primary function of the cerebellum? A\) Memory consolidation B\) Coordination of voluntary movement C\) Regulation of autonomic functions D\) Interpretation of sensory input Answer: B) Coordination of voluntary movement Which structure is located in the diencephalon and is responsible for relaying sensory information to the cerebral cortex? A\) Thalamus B\) Hypothalamus C\) Pineal gland D\) Pituitary gland Answer: A) Thalamus Which of the following is a characteristic of the sympathetic nervous system? A\) Increases heart rate B\) Stimulates digestion C\) Promotes rest and repair D\) Decreases respiratory rate Answer: A) Increases heart rate The parasympathetic nervous system is primarily associated with which of the following functions? A\) Fight or flight response B\) Rest and digest C\) Stress response D\) Blood pressure elevation Answer: B) Rest and digest IMAGING OF BRAIN AND SPINAL CORD Which imaging technique is most commonly used to visualize the brain in cases of acute stroke? A\) MRI with contrast B\) CT scan C\) Ultrasound D\) X-ray Answer: B) CT scan Which part of the brain is best seen on a coronal MRI section? A\) Cerebellum B\) Temporal lobes C\) Frontal lobes D\) Medulla oblongata Answer: C) Frontal lobes CRANIAL FOSSAE Which of the following is a characteristic feature of the posterior cranial fossa? A\) It houses the frontal lobe. B\) It contains the brainstem and cerebellum. C\) It contains the optic nerve. D\) It houses the pineal gland. Answer: B) It contains the brainstem and cerebellum Which foramen in the posterior cranial fossa transmits the spinal cord and the vertebral arteries? A\) Foramen magnum B\) Jugular foramen C\) Internal acoustic meatus D\) Hypoglossal canal Answer: A) Foramen magnum Which of the following structures passes through the foramen rotundum? A\) Maxillary nerve (V2) B\) Mandibular nerve (V3) C\) Facial nerve (VII) D\) Oculomotor nerve (III) Answer: A) Maxillary nerve (V2) During neural tube development, the forebrain (prosencephalon) gives rise to which of the following structures? A\) Cerebellum and pons B\) Thalamus and hypothalamus C\) Medulla oblongata D\) Spinal cord Answer: B) Thalamus and hypothalamus Which of the following is derived from the alar plate of the neural tube? A\) Dorsal root ganglia B\) Ventral horn of the spinal cord C\) Sensory neurons D\) Motor neurons Answer: C) Sensory neurons Failure of the neural tube to close properly can lead to which of the following conditions? A\) Hydrocephalus B\) Spina bifida C\) Meningitis D\) Intracranial hemorrhage Answer: B) Spina bifida Which of the following structures does the posterior cerebral artery supply? A\) Medial aspect of the frontal and parietal lobes B\) Occipital lobe C\) Lateral aspects of the temporal lobes D\) Thalamus and hypothalamus Answer: B) Occipital lobe Which of the following is the major blood supply to the spinal cord? A\) Internal carotid artery B\) Basilar artery C\) Vertebral artery D\) Anterior spinal artery Answer: D) Anterior spinal artery A stroke in the anterior cerebral artery (ACA) would most likely affect which part of the body? A\) The face and hands B\) The lower limbs C\) The upper limbs D\) The visual field Answer: B) The lower limbs Which of the following is true regarding the pia mater? A\) It forms a protective barrier between the brain and blood vessels. B\) It is the outermost meningeal layer. C\) It contains the dural sinuses. D\) It is closely attached to the surface of the brain and spinal cord. Answer: D) It is closely attached to the surface of the brain and spinal cord. Which of the following is the main function of the subarachnoid space? A\) Cushioning the brain B\) Housing the brain\'s blood vessels C\) Absorbing cerebrospinal fluid (CSF) D\) Providing structural support to the brain Answer: A) Cushioning the brain In which space would you expect to find a subdural hematoma? A\) Between the dura and arachnoid mater B\) Between the arachnoid and pia mater C\) Between the skull and dura mater D\) Inside the spinal cord Answer: A) Between the dura and arachnoid mater The foramen of Monro connects which two ventricles? A\) Lateral ventricle and third ventricle B\) Third ventricle and fourth ventricle C\) Lateral ventricle and fourth ventricle D\) Third ventricle and cerebral aqueduct Answer: A) Lateral ventricle and third ventricle Which of the following ventricles contains the choroid plexus responsible for cerebrospinal fluid (CSF) production? A\) Lateral ventricles B\) Third ventricle C\) Fourth ventricle D\) All of the above Answer: D) All of the above Blockage of the foramen of Monro can lead to which condition? A\) Hydrocephalus B\) Meningitis C\) Spinal cord compression D\) Intracranial hemorrhage Answer: A) Hydrocephalus Which cranial nerve is responsible for innervating the muscles of mastication? A\) Trigeminal nerve (V) B\) Facial nerve (VII) C\) Vagus nerve (X) D\) Glossopharyngeal nerve (IX) Answer: A) Trigeminal nerve (V) Which of the following cranial nerves is responsible for the sensation of taste on the posterior third of the tongue? A\) Vagus nerve (X) B\) Facial nerve (VII) C\) Glossopharyngeal nerve (IX) D\) Olfactory nerve (I) Answer: C) Glossopharyngeal nerve (IX) A patient with a lesion of the vagus nerve (X) would most likely present with which of the following? A\) Loss of taste sensation in the anterior two-thirds of the tongue B\) Difficulty swallowing and hoarseness C\) Paralysis of facial muscles D\) Loss of sensation from the cornea Answer: B) Difficulty swallowing and hoarseness Which of the following is primarily responsible for the sensory function of the spinal cord? A\) Anterior horn B\) Lateral horn C\) Dorsal root ganglion D\) Ventral root Answer: C) Dorsal root ganglion A lesion in the lateral corticospinal tract of the spinal cord would result in which of the following symptoms? A\) Loss of motor control in the lower limbs B\) Loss of sensation in the upper limbs C\) Difficulty with balance and coordination D\) Loss of autonomic function Answer: A) Loss of motor control in the lower limbs Which cranial nerve nuclei are located in the medulla oblongata? A\) Nuclei of cranial nerves III, IV, and VI B\) Nuclei of cranial nerves IX, X, and XII C\) Nuclei of cranial nerves V, VII, and IX D\) Nuclei of cranial nerves II, V, and XI Answer: B) Nuclei of cranial nerves IX, X, and XII Which of the following cranial nerves emerge from the pons? A\) Trigeminal nerve (V) B\) Facial nerve (VII) C\) Vestibulocochlear nerve (VIII) D\) All of the above Answer: D) All of the above Which part of the brain is responsible for the coordination of voluntary movements and balance? A\) Cerebellum B\) Medulla oblongata C\) Thalamus D\) Hypothalamus Answer: A) Cerebellum Which of the following is a function of the hypothalamus? A\) Control of heart rate and respiration B\) Regulation of body temperature and appetite C\) Coordination of motor movements D\) Processing sensory information Answer: B) Regulation of body temperature and appetite Which structure passes through the internal acoustic meatus? A\) Oculomotor nerve (III) B\) Facial nerve (VII) and Vestibulocochlear nerve (VIII) C\) Glossopharyngeal nerve (IX) D\) Trigeminal nerve (V) Answer: B) Facial nerve (VII) and Vestibulocochlear nerve (VIII) The middle cranial fossa houses which of the following structures? A\) Cerebellum and pons B\) Temporal lobe and pituitary gland C\) Occipital lobe and spinal cord D\) Medulla and midbrain Answer: B) Temporal lobe and pituitary gland Which cranial nerve exits the cranium through the jugular foramen? A\) Vagus nerve (X) B\) Hypoglossal nerve (XII) C\) Optic nerve (II) D\) Abducens nerve (VI) Answer: A) Vagus nerve (X) The mesencephalon (midbrain) gives rise to which of the following? A\) Cerebellum B\) Medulla oblongata C\) Tectum and tegmentum of the midbrain D\) Thalamus and hypothalamus Answer: C) Tectum and tegmentum of the midbrain Which structure is derived from the basal plate of the neural tube? A\) Dorsal root ganglia B\) Ventral horn of the spinal cord C\) Cerebral cortex D\) Thalamus Answer: B) Ventral horn of the spinal cord Which of the following is a derivative of the hindbrain (rhombencephalon)? A\) Medulla oblongata and pons B\) Thalamus and hypothalamus C\) Cerebrum D\) Midbrain Answer: A) Medulla oblongata and pons Which artery primarily supplies the occipital lobe and part of the temporal lobe? A\) Anterior cerebral artery B\) Middle cerebral artery C\) Posterior cerebral artery D\) Vertebral artery Answer: C) Posterior cerebral artery The vertebral arteries form which of the following vascular structures in the brain? A\) Internal carotid artery B\) Circle of Willis C\) Basilar artery D\) Anterior spinal artery Answer: B) Circle of Willis A blockage of the middle cerebral artery (MCA) could result in which of the following deficits? A\) Visual field deficits B\) Paralysis and sensory loss in the lower limb C\) Hemiparesis and aphasia D\) Ataxia and dysmetria Answer: C) Hemiparesis and aphasia Which of the following structures provides a barrier between the brain and the venous system? A\) Dural venous sinuses B\) Arachnoid granulations C\) Subdural space D\) Pia mater Answer: A) Dural venous sinuses What is the function of the arachnoid villi? A\) Absorbing cerebrospinal fluid (CSF) into the venous system B\) Producing cerebrospinal fluid (CSF) C\) Protecting the brain from injury D\) Supplying nutrients to the meninges Answer: A) Absorbing cerebrospinal fluid (CSF) into the venous system Which of the following meningeal layers is closest to the brain and spinal cord? A\) Arachnoid mater B\) Dura mater C\) Pia mater D\) Epidural space Answer: C) Pia mater The fourth ventricle connects to the spinal cord through which structure? A\) Cerebral aqueduct B\) Foramen of Monro C\) Foramen of Luschka D\) Central canal Answer: D) Central canal The choroid plexus is responsible for the production of which of the following? A\) Blood-brain barrier B\) Cerebrospinal fluid (CSF) C\) Meningeal layers D\) Neurons in the ventricular system Answer: B) Cerebrospinal fluid (CSF) A blockage in the aqueduct of Sylvius could result in which condition? A\) Hydrocephalus B\) Meningitis C\) Stroke D\) Cerebral hemorrhage Answer: A) Hydrocephalus Which cranial nerve is responsible for the sensation of smell? A\) Olfactory nerve (I) B\) Optic nerve (II) C\) Vagus nerve (X) D\) Trigeminal nerve (V) Answer: A) Olfactory nerve (I) Which cranial nerve controls the majority of the eye\'s movements, including pupil constriction? A\) Oculomotor nerve (III) B\) Trochlear nerve (IV) C\) Abducens nerve (VI) D\) Optic nerve (II) Answer: A) Oculomotor nerve (III) Which of the following is a function of the glossopharyngeal nerve (IX)? A\) Control of facial muscles B\) Taste sensation from the anterior two-thirds of the tongue C\) Sensory and motor function for the pharynx D\) Control of heart rate and respiration Answer: C) Sensory and motor function for the pharynx Which of the following is true regarding the gray matter of the spinal cord? A\) It is composed mainly of myelinated axons. B\) It is located on the outer surface of the spinal cord. C\) It is involved in sensory and motor processing. D\) It contains only motor neurons. Answer: C) It is involved in sensory and motor processing. Which of the following describes the function of the dorsal horn of the spinal cord? A\) Transmitting motor signals B\) Processing sensory information C\) Controlling autonomic functions D\) Coordinating reflexes Answer: B) Processing sensory information A lesion in the corticospinal tract at the level of the spinal cord would lead to which type of paralysis? A\) Upper motor neuron paralysis B\) Lower motor neuron paralysis C\) Sensory loss D\) Loss of autonomic function Answer: A) Upper motor neuron paralysis Which structure is part of the brainstem and is involved in controlling vital functions such as heart rate and respiration? A\) Thalamus B\) Medulla oblongata C\) Cerebellum D\) Basal ganglia Answer: B) Medulla oblongata The midbrain contains the substantia nigra, which is involved in which function? A\) Pain and temperature sensation B\) Regulation of mood and motor control C\) Sensory processing for vision and hearing D\) Reflex control of the eyes Answer: B) Regulation of mood and motor control Which cranial nerve nuclei are located in the pons? A\) Nuclei of cranial nerves V, VI, VII, and VIII B\) Nuclei of cranial nerves III, IV, and VI C\) Nuclei of cranial nerves IX, X, and XII D\) Nuclei of cranial nerves II, III, and IV Answer: A) Nuclei of cranial nerves V, VI, VII, and VIII Which of the following is a primary function of the cerebellum? A\) Memory formation B\) Coordination and regulation of voluntary movements C\) Sensory processing D\) Regulation of the autonomic nervous system Answer: B) Coordination and regulation of voluntary movements Which of the following structures is part of the diencephalon? A\) Cerebellum B\) Pineal gland C\) Medulla oblongata D\) Basal ganglia Answer: B) Pineal gland Damage to the cerebellum is most likely to result in which of the following? A\) Hemiplegia B\) Ataxia and loss of balance C\) Seizures D\) Visual deficits Answer: B) Ataxia and loss of balance Which sulcus separates the frontal and parietal lobes of the brain? A\) Central sulcus B\) Lateral sulcus (Sylvian fissure) C\) Parieto-occipital sulcus D\) Calcarine sulcus Answer: A) Central sulcus The Broca\'s area, responsible for speech production, is located in which lobe? A\) Parietal lobe B\) Occipital lobe C\) Temporal lobe D\) Frontal lobe Answer: D) Frontal lobe Which part of the brain is primarily responsible for processing auditory information? A\) Temporal lobe B\) Parietal lobe C\) Occipital lobe D\) Frontal lobe Answer: A) Temporal lobe Damage to the left hemisphere of the brain is most likely to result in which of the following? A\) Aphasia and difficulty with speech and language B\) Loss of visual processing C\) Loss of coordination and motor control D\) Impaired autonomic regulation Answer: A) Aphasia and difficulty with speech and language The sympathetic nervous system is primarily involved in which of the following responses? A\) Rest and digest B\) Fight or flight C\) Decreasing heart rate D\) Stimulating digestion Answer: B) Fight or flight Which of the following is a key difference between the sympathetic and parasympathetic nervous systems? A\) The sympathetic system releases acetylcholine, while the parasympathetic system releases norepinephrine. B\) The sympathetic system has long preganglionic fibers, while the parasympathetic system has short preganglionic fibers. C\) The parasympathetic system stimulates the \"fight or flight\" response, while the sympathetic system promotes rest and recovery. D\) The sympathetic system has a more widespread effect on the body compared to the parasympathetic system. Answer: D) The sympathetic system has a more widespread effect on the body compared to the parasympathetic system. Which neurotransmitter is primarily used by the parasympathetic nervous system at the postganglionic synapse? A\) Norepinephrine B\) Acetylcholine C\) Dopamine D\) Epinephrine Answer: B) Acetylcholine Which imaging modality is best suited for visualizing soft tissue structures like the brain and spinal cord? A\) X-ray B\) CT scan C\) MRI D\) Ultrasound Answer: C) MRI Which of the following is a typical finding in a brain MRI of a patient with multiple sclerosis? A\) Enlarged ventricles without lesions B\) White matter lesions in periventricular regions C\) Hyperintensities in the basal ganglia D\) Widespread brain atrophy Answer: B) White matter lesions in periventricular regions Which of the following features on a CT scan is indicative of an acute hemorrhagic stroke? A\) Hypodense area in the brain B\) Hyperdense area in the brain C\) No change in the brain\'s appearance D\) Enlargement of the ventricles Answer: B) Hyperdense area in the brain Which of the following is a typical feature of an epidural hematoma on imaging? A\) Crescent-shaped lesion with mass effect B\) Biconvex shape, limited to one side of the brain C\) Diffuse white matter changes D\) Fluid accumulation in the subarachnoid space Answer: B) Biconvex shape, limited to one side of the brain Which structure in the spinal cord is responsible for the sensation of touch, pressure, and proprioception? A\) Anterior horn B\) Lateral horn C\) Dorsal column D\) Corticospinal tract Answer: C) Dorsal column The white matter of the spinal cord is primarily composed of: A\) Myelinated axons B\) Cell bodies of neurons C\) Unmyelinated axons D\) Glial cells Answer: A) Myelinated axons Which of the following describes the function of the corticospinal tract? A\) Sensory input from the skin and muscles B\) Motor control of voluntary movement C\) Coordination of reflexes D\) Autonomic regulation of heart rate and breathing Answer: B) Motor control of voluntary movement Which part of the brainstem contains the nuclei responsible for regulating cardiac and respiratory functions? A\) Medulla oblongata B\) Pons C\) Midbrain D\) Thalamus Answer: A) Medulla oblongata The superior colliculus, located in the midbrain, is involved in which of the following functions? A\) Vision and eye movements B\) Auditory processing C\) Regulation of heart rate D\) Memory formation Answer: A) Vision and eye movements Which cranial nerve exits the brainstem at the level of the midbrain? A\) Oculomotor nerve (III) B\) Trochlear nerve (IV) C\) Trigeminal nerve (V) D\) Vagus nerve (X) Answer: A) Oculomotor nerve (III) A 45-year-old male presents with a severe headache and difficulty in moving his right eye. Imaging reveals a mass in the cavernous sinus. Which cranial nerves are most likely involved? A\) CN II and CN III B\) CN III, CN IV, CN V1, and CN VI C\) CN V2 and CN VI D\) CN I, CN II, and CN III Answer: B) CN III, CN IV, CN V1, and CN VI Explanation: The cavernous sinus houses the oculomotor (III), trochlear (IV), ophthalmic (V1), and abducens (VI) nerves. A mass here can affect these cranial nerves. During embryonic development, the neural tube undergoes differentiation into primary brain vesicles. Which of the following is NOT one of the primary brain vesicles? A\) Prosencephalon B\) Mesencephalon C\) Rhombencephalon D\) Myelencephalon Answer: D) Myelencephalon Explanation: The primary brain vesicles are the prosencephalon, mesencephalon, and rhombencephalon. The myelencephalon develops later as part of the rhombencephalon. A newborn exhibits signs of hydrocephalus and poor muscle tone. Upon imaging, the forebrain appears abnormally small, and the ventricles are dilated. Which primary brain vesicle is most likely affected? A\) Prosencephalon B\) Mesencephalon C\) Rhombencephalon D\) Myelencephalon Answer: A) Prosencephalon Explanation: Hydrocephalus, especially with abnormalities in the forebrain and dilated ventricles, suggests issues with the prosencephalon. A 68-year-old male with a history of hypertension presents with sudden onset of right-sided weakness and difficulty speaking. CT scan shows a right middle cerebral artery (MCA) infarction. Which part of the brain is most likely affected? A\) Temporal lobe and occipital lobe B\) Parietal lobe and frontal lobe C\) Occipital lobe and cerebellum D\) Medulla oblongata and pons Answer: B) Parietal lobe and frontal lobe Explanation: The MCA supplies the lateral aspects of the frontal, temporal, and parietal lobes. MCA infarctions typically affect motor and speech centers in the frontal and parietal lobes. A patient undergoes a stroke involving the anterior cerebral artery (ACA). What area of the body would most likely show signs of paralysis? A\) Upper limb and face B\) Lower limb C\) Visual fields D\) Respiratory muscles Answer: B) Lower limb Explanation: The ACA primarily supplies the medial aspects of the frontal and parietal lobes, which control lower limb movement. A 28-year-old woman presents with severe headache, nausea, and vomiting. MRI reveals a subarachnoid hemorrhage. Which structure is likely affected in this condition? A\) Epidural space B\) Subdural space C\) Subarachnoid space D\) Dural folds Answer: C) Subarachnoid space Explanation: A subarachnoid hemorrhage involves bleeding into the subarachnoid space, where cerebrospinal fluid circulates. During a routine spinal surgery, the surgeon notices a structure that anchors the spinal cord to the vertebral column. Which structure is he observing? A\) Arachnoid mater B\) Dura mater C\) Denticulate ligament D\) Pia mater Answer: C) Denticulate ligament Explanation: The denticulate ligament is a modification of the pia mater that helps anchor the spinal cord to the vertebral column. A patient with facial trauma develops a swollen eye and signs of venous congestion. CT scan reveals thrombosis in the cavernous sinus. Which cranial nerve dysfunction is most likely? A\) Oculomotor nerve (CN III) B\) Facial nerve (CN VII) C\) Trigeminal nerve (CN V) D\) Glossopharyngeal nerve (CN IX) Answer: A) Oculomotor nerve (CN III) Explanation: The cavernous sinus is closely associated with the oculomotor nerve (CN III), so thrombosis here often leads to dysfunction of CN III. VENTRICULAR SYSTEM OF BRAIN A patient presents with increasing intracranial pressure and abnormal CSF flow. MRI shows enlargement of the ventricles but no obstruction. Which condition is most likely responsible for this finding? A\) Hydrocephalus ex vacuo B\) Non-communicating hydrocephalus C\) Communicating hydrocephalus D\) Chiari malformation Answer: A) Hydrocephalus ex vacuo Explanation: Hydrocephalus ex vacuo occurs when there is brain atrophy without blockage of CSF flow, leading to ventricular enlargement. A 5-year-old child presents with irritability, vomiting, and headache. MRI shows blockage of the cerebral aqueduct, leading to dilated lateral and third ventricles. What is the most likely diagnosis? A\) Hydrocephalus ex vacuo B\) Obstructive hydrocephalus C\) Normal pressure hydrocephalus D\) Meningitis Answer: B) Obstructive hydrocephalus Explanation: Blockage of the cerebral aqueduct can lead to obstructive hydrocephalus, causing increased pressure and ventricular enlargement. A 60-year-old man presents with loss of taste on the anterior 2/3 of the tongue, along with dry mouth and difficulty swallowing. Which cranial nerve is most likely affected? A\) Glossopharyngeal nerve (CN IX) B\) Vagus nerve (CN X) C\) Facial nerve (CN VII) D\) Hypoglossal nerve (CN XII) Answer: C) Facial nerve (CN VII) Explanation: The facial nerve (CN VII) is responsible for taste on the anterior 2/3 of the tongue and controls salivation and some aspects of swallowing. A 32-year-old man presents with weakness and sensory loss in the upper limbs, but his lower limbs remain unaffected. MRI shows a lesion in the cervical region of the spinal cord. What is the most likely cause of his symptoms? A\) Anterior horn cell lesion B\) Posterior column lesion C\) Lateral corticospinal tract lesion D\) Central cord syndrome Answer: D) Central cord syndrome Explanation: Central cord syndrome, often caused by cervical spinal cord injuries, leads to weakness and sensory loss in the upper limbs while sparing the lower limbs. A 50-year-old woman with a history of hypertension presents with sudden-onset weakness in her right arm, slurred speech, and difficulty swallowing. CT reveals a stroke in the medulla. Which cranial nerve nuclei are most likely involved? A\) CN I and CN II B\) CN III and CN IV C\) CN IX and CN X D\) CN V and CN VII Answer: C) CN IX and CN X Explanation: The medulla contains the nuclei for the glossopharyngeal (CN IX) and vagus (CN X) nerves, which are involved in swallowing and speech.