Neuroanatomy

Question 1

Foramina of Munro are channels that connect

Select one:
1. Lateral and third ventricles
2. Third and fourth ventricle
3. Two third ventricle
4. 4th ventricle and spinal canal
5. Two lateral ventricles

Answer 1

Lateral and third ventricles

In the brain, the interventricular foramina of Monro connect the 2 lateral ventricles with the 3rd ventricle at
the midline. These foramen serve as conduits for cerebrospinal fluid (CSF) produced in the lateral ventricles to reach the third ventricle and then the rest of the brain’s ventricular system.

Question 2

Which one of the following is seen as a key function of the non-dominant cerebral hemisphere?

Select one:
1. Logical reasoning
2. Pictorial memory
3. Analytical capacity
4. Verbal learning
5. Language functions

Answer 2

Pictorial memory

Disorders of verbal and pictorial memory are commonly dissociated by brain injury with verbal memory being affected in left and picture memory predominantly by right brain injury; However, this is disputed as many subjects use verbal encoding when remembering pictures.

Question 3

Which of the following enzymes is exclusively seen in astrocytes?

Select one:
1. COMT
2. MAO-B
3. Glutamate dehydrogenase
4. Tyrosine hydroxylase
5. Acetylcholinesterase

Answer 3

Glutamate dehydrogenase

Glutamate dehydrogenase is seen only in astrocytes and not in other glial cells.

Question 4

Which of the following is correct with respect to blood brain barrier?

Select one:
1. Lipophilic substances penetrate the barrier better
2. Basal forebrain lacks the barrier
3. Endothelial cells form gap junctions
4. Microglial foot processes form the blood brain barrier
5. Inflammation can strengthen blood brain barrier

Answer 4

Lipophilic substances penetrate the barrier better

Lipid soluble molecules, such as ethanol and caffeine can penetrate through the barrier relatively easily via
the lipid membranes of the cells. Brain endothelial cells are joined by tight junctions of high electrical
resistance providing an effective barrier against molecules.

Question 5

What is the function of an endosome?

Select one:
1. Recycling of cell membrane
2. Production of hydrogen peroxide
3. Transcribe information from mRNA
4. Check the synthesised proteins for structural conformity before delivery
5. Lipid peroxidation

Answer 5

Recycling of cell membrane

An endosome is a membrane-bound cellular compartment of the endocytic membrane transport pathway extending from the plasma membrane to the lysosome. Molecules internalized from the plasma membrane are transported via endosomes to lysosomes for degradation; similarly molecules can also be recycled back to the plasma membrane.

Question 6

The most common type of neuronal cells seen in the cerebral cortex is

Select one:
1. Stellate cell
2. Spindles cells
3. Granule cell
4. Purkinje cells
5. Pyramidal cells

Answer 6

Pyramidal cells

The pyramidal neurons with their triangular-shaped cell bodies make up nearly 75% of the cortical neurons. Stellate cells (25%) are present in all the layers except layer 1.

Question 7

Which of the following cells are the largest of all neurons in the human brain?

Select one:
1. Betz cells
2. Basket cells
3. Golgi cells
4. Purkinje cells
5. Stellate cells

Answer 7

Betz cells

Large pyramidal cells called Betz cells are seen in the primary motor cortex.Betz cells are pyramidal cell
neurons located within the fifth layer of the grey matter in the primary motor cortex. These can reach a
diameter of 100 μm in some cases, and are known to be the largest neurons in the nervous system. Betz
cells represent about 10% of the total pyramidal cell population in layer V of the human primary motor
cortex.

Question 8

Which of the following nuclei of basal ganglia contains melanin pigment?

Select one:
1. Globus pallidus
2. Substantia nigra
3. Caudate nucleus
4. Subthalamic nuclei
5. Putamen

Answer 8

Substantia nigra

Substantia nigra appears black because of melanin pigment.

Question 9

OCD is associated with an abnormality in which of the following parts of the brain?

Select one:
1. Inferior olivary nucleus
2. Medial temporal lobe
3. Dendate nucleus
4. Lentiform nucleus
5. Red nucleus

Answer 9

Lentiform nucleus

Basal ganglia dysfunction is implicated in OCD. The components of basal ganglia are the caudate nucleus,
the putamen and globus pallidus. Putamen and globus pallidus together form the lenticular/lentiform nuclei.
Neuroimaging studies with PET scan suggest the involvement of both caudate and lentiform nuclei
dysfunction in patients with OCD.

Question 10

Huntington’s disease is caused due to degeneration of

Select one:
1. Pons
2. Prefrontal cortex
3. Cerebellum
4. Striatum
5. Subthalamic nucleus

Answer 10

Striatum

Huntington’s disease is caused due to degeneration of the striatum (mainly caudate nucleus) and selective
loss of GABA-ergic neurones.

Question 11

Electrical synapses are seen in

Select one:
1. Skin
2. Olfactory epithelium
3. Bone marrow
4. Retina
5. Lungs

Answer 11

Retina

An electrical synapse is formed at a narrow gap between the pre- and postsynaptic neurons (gap junction) and helps conduct electrical messages across cells. Electrical synapses are abundant both in the retina and cerebral cortex of animals.

Question 12

Nominal aphasia can be localised to

Select one:
1. Angular gyrus
2. Posterior parietal cortex
3. Inferior frontal gyrus
4. Superior temporal gyrus
5. Broca’s area

Answer 12

Angular gyrus

Posterior lesions involving parietal cortex, particularly of the angular gyrus, can produce quite pronounced
anomia for visually recognized objects and may be associated with alexia.

Question 13

Regarding the blood supply of language areas which of the following is correct?

Select one:
1. Wernicke’s area is supplied by posterior cerebral artery
2. Transient ischemia of carotid system produces aphasia
3. Transient ischemia of carotid system produces dysarthria
4. Vertebrobasilar system supplies motor speech area
5. Right sided carotid block produces Broca’s aphasia

Answer 13

Transient ischemia of carotid system produces aphasia

The carotid system is responsible for supplying language areas. A lesion can produce transient aphasia.

Question 14

Which one among the following types of neuroglia is present in the peripheral nervous system?

Select one:
1. Schwann cells
2. Astrocytes
3. Microglia
4. Ependyma
5. Oligodendrocytes

Answer 14

Schwann cells

Neuroglia, also called as interstitial cells outnumber neurones by a factor of five to ten times. The main
types of neuroglial cells in the central nervous system include Microglia, Ependyma, Oligodendrocytes and
Astrocytes. The main types of neuroglia that is present in the peripheral nervous system include Schwann
cells and satellite cells.

Question 15

Which of the following cells are uniquely found in the cerebellum?

Select one:
1. Purkinje cells
2. Betz cells
3. Pyramidal cells
4. Granule cells
5. Stellate cells

Answer 15

Purkinje cells

Purkinje cells are a class of GABAergic neurons located in the cerebellar cortex only. Purkinje cells send
inhibitory projections to the deep cerebellar nuclei and constitute the sole output of all motor coordination in
the cerebellar cortex.

Question 16

In what percentage of left-handed people the left hemisphere is dominant?

Select one:
1. 90
2. 20
3. 16
4. 10
5. 64

Answer 16

64%

The hemisphere contralateral to the dominant hand is the dominant hemisphere, and it mediates language
and speech functions. In right-handed people, the left hemisphere is dominant. However in 10% of righthanded people the right hemisphere is dominant. In left handed people only about 20% are right
hemisphere dominant as expected, with 64% left hemisphere dominant and 16% showing bilateral
dominance. Generally, apraxia results from dysfunction in the dominant hemisphere and agnosia results from dysfunction in the non-dominant hemisphere.

Question 17

Lesions in the subthalamic area are associated with which of the following movement disorders?

Select one:
1. Hemiballismus
2. Huntington’s chorea
3. Dystonia
4. Athetosis
5. Parkinsons disease

Answer 17

Hemiballismus

Lesions in the corpus striatum are associated with dystonia, athetosis and chorea. Lesions in the
subthalamic nucleus are associated with Hemiballismus. Lesions in the substantia nigra are associated with Parkinson’s disease.

Question 18

The part of hypothalamus that acts as a satiety centre is

Select one:
1. Supraoptic nucleus
2. Ventromedial hypothalamus
3. Paraventricular hypothalamus
4. Suprachiasmatic nucleus
5. Lateral hypothalamus

Answer 18

Ventromedial hypothalamus

Ventromedial hypothalamus acts as a satiety centre; lateral hypothalamus as a feeding centre. In animals
with a lesion of the ventromedial hypothalamus abnormal feeding behaviours including hyperphagia that leads to obesity are noted.

Question 19

A 62-year-old gentleman presented to the outpatients department with a history of changes in personality,
socially disinhibited behaviour, poor judgement and irritability. His carer also reported a recent history of
urinary incontinence. Which part of the brain is most likely to be affected?

Select one:
1. Occipital lobe
2. Frontal lobe
3. Cerebellum
4. Temporal Lobe
5. Parietal lobe

Answer 19

Frontal lobe

Frontal lobe dysfunction would include features such as disinhibition, loss of abstract ability, errors of
judgement, irritability, elevated mood, and childishness, lack of drive, impaired initiation, attention and concentration.

Question 20

The thalamus and hypothalamus are constituents of which of the following embryological structures?

Select one:
1. Myelencephalon
2. Metencephalon
3. Telencephalon
4. Mesencephalon
5. Diencephalon

Answer 20

Diencephalon

During ontogeny, the midline neural tube differentiates into the following vesicles;
1. Prosencephalon, which
differentiates into the Telencephalon and Diencephalon
2. Mesencephalon (midbrain structures) and
3.Rhombencephalon which differentiates into the Metencephalon and Myelencephalon.

The hypothalamus and thalamus are constituents of the diencephalon.

Question 21

Mrs. X is an 83-year-old lady who has been diagnosed with early stages of Alzheimer’s disease. The brain
region, which could show prominent changes, is;

Select one:
1. Prefrontal cortex
2. Entorhinal cortex
3. Superior temporal gyrus
4. Caudate nucleus
5. Prefrontal cortex

Answer 21

Entorhinal cortex

Profound loss of layer two entorhinal cortex neurons occurs in very mild Alzheimer’s disease. The
entorhinal cortex plays a crucial role connecting the neocortex and hippocampal formation and is affected
severely likely contributing to memory impairment.

Question 22

Which function of the brain is served by angular gyrus?

Select one:
1. Balance & co-ordination
2. Motor movements
3. Language
4. Memory
5. Executive functions

Answer 22

Language

The angular gyrus is a region of the inferior parietal lobe of the brain that is involved in the processing of
auditory and visual input and in the comprehension of language. It is Brodmann area 39 of the human brain.
Lesions are associated with anomia

Question 23

What proportion (in percentage) of the brain is occupied by prefrontal cortex?

Select one:
1. 20
2. 70
3. 50
4. 30
5. 10

Answer 23

30%

The prefrontal cortex (PFC) is the anterior part of the frontal lobes of the brain, lying in front of the motor
and premotor areas, which occupies nearly 30% of the brain.

Question 24

Which lobe is initially affected in Alzheimer’s disease?

Select one:
1. Prefrontal lobe
2. Temporal lobe
3. Frontal lobe
4. Parietal lobe
5. Occipital lobe

Answer 24

Temporal lobe

The temporal lobes, especially the hippocampal areas in them, are affected early in Alzheimer’s disease.
Medial temporal lobe atrophy and loss of hippocampal volume is one of the earliest findings seen in
patients with Alzheimer’s disease.

Question 25

Which one among the following structures is a constituent of mesencephalon?

Select one:
1. Subthalamus
2. Cerebellum
3. Red nucleus
4. Corpus striatum
5. Medullary centre

Answer 25

Red nucleus

Prosencephalon includes
1. Telencephalon, which gives rise to cerebral hemispheres and contains the pallium, rhinencephalon, and basal ganglia
2. Diencephalon consisting of thalamus, subthalamus,
hypothalamus and epithalamus consisting of the habenular nucleus and pineal gland.

Mesencephalon represents the growing midbrain and consists of
1.Tectum, in turn consisting of the corpora quadrigemina, made up of the superior and inferior colliculi
2. Basis pedunculi
3. Tegmentum containing the red nucleus, fibre tracts and grey matter surrounding the cerebral aqueduct.

Finally, the rhombencephalon includes 1.Metencephalon consisting of the pons, the oral part of the medulla oblongata and cerebellum and
2.Myelencephalon consisting of the caudal part of the medulla oblongata.

Question 26

Neural crest cells originate from

Select one:
1. Endoderm
2. Pharyngeal pouch
3. Mesoderm
4. Ectoderm
5. Neural tube

Answer 26

Neural tube

Neural crest refers to a group of embryonic cells that originate from the neural tube (the precursor of the
spinal cord) but later dissociate from the central nervous system. The embryonic crest cells migrate to
numerous locations in the body to form diverse structures such as

(1) the neurons and glial cells of the sensory, sympathetic, and parasympathetic nervous systems, (2) the adrenergic cells of the adrenal
medulla,
(3) the pigment-containing cells of the epidermis, and (4) many of the skeletal and connective
tissue components of the head.

Question 27

Which area of the brain is associated with ‘social valuation’?

Select one:
1. Calcarine fissure
2. Lingual gyrus
3. Orbitofrontal cortex
4. Anterior cingulate gyrus
5. Hippocampal gyrus

Answer 27

Orbitofrontal cortex

Orbitofrontal cortex is often included as the brain region with a prominent role in social valuation, though many other regions such as the temporoparietal junction, anterior cingulate cortex and fusiform gyrus also play a part in this function. Damage to OFC can cause a pseudopsychopathic syndrome.

Question 28

Which of the following is a purely motor cranial nerve?

Select one:
1. Facial nerve
2. Oculomotor nerve
3. Vagus nerve
4. Glossopharyngeal nerve
5. Vestibulocochlear nerve

Answer 28

Oculomotor

Pure sensory-Olfactory, optic and Vestibulocochlear nerves.
Pure motor-Oculomotor, trochlear, abducens, accessory and hypoglossal nerve.
Mixed-Trigeminal, facial, glossopharyngeal, vagus nerve.

Question 29

Which of the following statements about microglia is correct?

Select one:
1. It is mainly responsible for myelination
2. It constitutes 70% of glial population in brain
3. It is mesodermal in origin
4. It is sensitive to sodium channel stimulation
5. It is present outside brain and spinal cord

Answer 29

It is mesodermal in origin

Unlike macroglia (astrocytes and oligodendrocytes) and neurons, which are derived from neuroectoderm,
microglial progenitors arise from peripheral mesodermal (myeloid) tissue.

Question 30

Primary sensory cortex is located in which of the following areas?

Select one:
1. Superior temporal area
2. Inferior parietal lobule
3. Dorsolateral prefrontal cortex
4. Precentral gyrus
5. Postcentral gyrus

Answer 30

Postcentral gyrus

Brodmann areas 3, 1 and 2 comprise the primary somatosensory cortex of the human brain (or S1) - most of which is located on the postcentral gyrus. Lesions affecting the primary somatosensory cortex produce characteristic symptoms including: agraphesthesia, astereognosia, loss of vibration, proprioception and fine touch. The primary motor cortex (or M1) is a brain region that in humans is located in the posterior portion of the frontal lobe. It works in association with pre-motor areas to plan and execute movements. M1 is located on precentral gyrus.

Question 31

A patient presents with rapid onset personality changes and memory difficulties. On examination, he has homonymous superior quadrantanopia. Where is the lesion likely to be?

Select one:
1. Optic chiasma
2. Lateral Geniculate Body
3. Occipital lobe
4. Temporal lobe
5. Retina

Answer 31

Temporal lobe

A lesion anterior to the optic chiasma results in loss of the visual field to ipsilateral eye. Any lesion of or
posterior to the optic chiasma results in visual defects in both eyes. Lesions behind the chiasma result in
homonymous defects. Homonymous hemianopia results from loss of the optic tract or radiation on one side.

Damage to Myers loop results in homonymous superior quadrantanopia and it may be the first indication of a lesion within the temporal lobe.

Question 32

Which of the following is affected if there is an occlusion of the posterior cerebral artery?

Select one:
1. Cingulate gyrus
2. Corpus callosum
3. Dentate gyrus
4. Urcinate gyrus
5. Arcuate fasciculus

Answer 32

Dentate gyrus

The dentate gyrus is a part of the hippocampal formation. It is one of the few areas of the human brain where new neurons are continuously produced in adulthood. The posterior cerebral artery provides blood supply of the hippocampal formation.

Question 33

Which one of the following is not a function of astrocytes?

Select one:
1. Maintaining the blood brain barrier
2. None of the above
3. Nutrition of neurons
4. Breakdown of some neurotransmitters
5. Formation of CNS myelin sheath

Answer 33

Formation of CNS myelin sheath

Formation of CNS myelin sheath is a function of oligodendrocytes and not astrocytes. Oligodendrocytes are seen in CNS (not in peripheral nerves, where Schwann cells replace them). They produce myelin sheaths, which help in saltatory conduction (pole to pole jumping), which quicken the process of signal transmission.

Question 34

The motor cortex occupies

Select one:
1. Heteromodal association cortices
2. Supplementary motor area
3. Frontal eye fields
4. Precentral gyrus
5. Postcentral gyrus

Answer 34

Precentral gyrus

Primary Motor Cortex is located in the precentral gyrus, which also encompasses premotor, supplementary motor and frontal eye fields. Except olfaction, all other sensations are relayed via the thalamus to sensory cortex. It occupies the postcentral gyrus.

Question 35

Which of the following is NOT a part of Papez circuit?

Select one:
1. Mamillary body
2. Parahippocampal gyrus
3. Cingulate gyrus
4. Hippocampus
5. Heschl’s gyrus

Answer 35

Heschl’s gyrus

The Papez circuit consists of the following: Hippocampal formation, fornix, mammillary bodies,
mammillothalamic tract, anterior thalamic nucleus, cingulate gyrus, Parahippocampal gyrus, entorhinal
cortex and perforant pathway ending in the hippocampus

Question 36

The limbic Papez circuit includes which of the following structures?

Select one:
1. Hippocampus
2. Temporal pole
3. Medullary centre
4. Trapezoid body
5. Red nucleus

Answer 36

Hippocampus

Amygdala, septal nuclei, fornix, parahippocampal gyrus and mammillothalamic tract are all constituents ofthe limbic system in addition to the hippocampus.

Question 37

The internal capsule is supplied by which of the following structures?

Select one:
1. Anterior cerebral artery
2. Basilar artery
3. Posterior inferior cerebellar artery
4. Middle cerebral artery
5. Circle of Willis

Answer 37

Circle of WIllis

The internal carotid artery enters the circle of Willis and divides to form the anterior cerebral and middle
cerebral arteries.

The anterior cerebral artery supplies the medial and superior lateral aspects of the cerebral cortex to the parietal/occipital border. The middle cerebral artery supplies the greater part of the lateral aspect of the cerebral cortex.

The middle cerebral artery supplies the Broca’s and Wernicke’s area in the dominant hemispheres.

The posterior cerebral artery supplies the inferomedial temporal lobe and the occipital lobe.

Internal capsule contains traversing corticospinal tract and receives blood supply from different parts of the circle of Willis. The superior portion of the anterior limb is supplied by lenticulostriate branches of the middle cerebral artery while the inferior half is supplied by the recurrent artery of Heubner arising from the anterior cerebral artery. The genu receives supply from lenticulostriate branches of middle cerebral artery, while posterior limb is supplied by the lenticulostriate branches of middle cerebral artery (superior half) and anterior choroidal artery off of the internal carotid artery (inferior half).

Question 38

Which artery supplies most of the corpus callosum?

Select one:
1. Middle cerebral artery
2. Anterior cerebral artery
3. Posterior inferior cerebral artery
4. Posterior cerebral artery
5. Basilar artery

Answer 38

Anterior cerebral artery

Infarcts of the corpus callosum are not common due likely to a rich blood supply from the main arterial
systems, specifically the anterior cerebral and anterior communicating, but also from posterior cerebral
arteries.

Question 39

Which one of the following effects is associated with lesions of the left hemisphere?

Select one:
1. Prospagnosia
2. Apraxia
3. Autotopagnosia
4. Alexia with Agraphia
5. Visual spatial Agnosia

Answer 39

Alexia with Agraphia

Left hemisphere lesions may produce alexia, agraphia, acalculia, colour anomia without aphasia, Broca’s
aphasia, Wernicke’s aphasia and Gerstmann syndrome.

Right, hemisphere lesions may produce
constructional apraxia, prospagnosia, autotopagnosia, visual spatial agnosia, anosognosia, receptive
amusia, and contralateral neglect.

Question 40

Which one of the following is a function of oligodendrocytes?

Select one:
1. Metabolic clearance of transmitters
2. Gliosis and scar formation
3. Structural support of neurons
4. Contributing to the blood brain barrier
5. Myelination

Answer 40

Myelination

The function of astrocytes includes providing structural support of neurones, forming CNS neuroglial scar tissue (gliosis), phagocytosis and also contributing to the blood brain barrier. The function of
oligodendrocytes includes CNS myelin sheath formation and phagocytosis.

Question 41

Synaptogenesis is at its highest during which of the following phases of life?

Select one:
1. Preschool years
2. Immediately preceding puberty
3. During adolescence
4. After 65 years of age
5. First 2 years of life

Answer 41

First 2 years of life

Synaptogenesis occurs very rapidly from the second trimester through the first ten years or so of life. The
peak of synaptogenesis occurs within the first two postnatal years.

Question 42

Which of the following statements regarding amygdala is NOT correct?

Select one:
1. Damage leads to impaired fear conditioning
2. Emotional face processing involves amygdala activity
3. It is involved in emotional memory
4. Learning does not occur in the absence of memory consolidation mediated by amygdala
5. Monkeys with amygdala damage show impaired maternal behaviours

Answer 42

Learning does not occur in the absence of memory consolidation mediated by amygdala

Amygdala is involved in rating the emotional importance of an experience and activating the level of
hippocampal response accordingly. Amygdala damage leads to loss of fear conditioning and in monkeys, loss of maternal behaviour has also been noted. Despite the amygdala damage, learning and consolidation of memory can occur, especially in the absence of emotional valence and arousal.

Question 43

Which part of the brain is last to mature?

Select one:
1. Amygdala
2. Prefrontal cortex
3. Midbrain
4. Parahippocampal cortex
5. Thalamus

Answer 43

Prefrontal cortex

In phylogeny as in ontogeny, the association cortex of the frontal lobe, also known as the prefrontal cortex,
is a late-developing region of the neocortex. It is also one of the cortical regions to undergo the greatest
expansion in the course of both evolution and individual maturation. In the human adult, the prefrontal cortex constitutes as much as nearly one-third of the totality of the neocortex.

Question 44

Which area of the brain is responsible for normal arithmetical ability?

Select one:
1. Fusiform gyrus
2. Angular Gyrus
3. Cuneus gyrus
4. Cingluate gyrus
5. Supramarginal gyrus

Answer 44

Angular Gyrus

The angular gyrus is situated in the parietal lobe, that lies near the upper boundary of the temporal lobe,
and immediately posterior to the supramarginal gyrus. It is involved in the cognitive domains of language,
number processing, spatial cognition, memory retrieval, attention, and theory of mind. Damage to the left angular gyrus results in computational difficulties such as acalculia and anarithmetica.

Question 45

Which one of the following types of neurons has no axons?

Select one:
1. Golgi type 1 neurons
2. Amacrine neurons
3. Polysynaptic neurons
4. Golgi type 2 neurons
5. Bipolar neurons

Answer 45

Amacrine neurons

Neuronal cells are classified on the basis of their size into three types: Golgi type 1 - Long axon; Golgi type
2 - Short axon terminating near the parent cell; Amacrine neurons - No axon.

Question 46

Cranial nerves can carry both sensory and motor impulses. Which one of the following cranial nerves has only a motor component?

Select one:
1. Vestibulocochlear
2. Glossopharyngeal
3. Olfactory
4. Optic
5. Abducens

Answer 46

Abducens

Pure sensory - Olfactory, optic and vestibulocochlear nerves.
Pure motor - Oculomotor, trochlear, abducens, accessory and hypoglossal nerves.
Mixed -Trigeminal, facial, glossopharyngeal, vagus nerves.
Autonomic- Facial, glossopharyngeal and vagus nerves

Question 47

Forced utilisation behaviour can be a feature of damage to which of the following structures?

Select one:
1. Cerebellar damage
2. Parietal lobe damage
3. Temporal lobe damage
4. Occipital lobe damage
5. Frontal lobe damage

Answer 47

Frontal lobe damage

If the frontal lobe superior to the eye (orbitofrontal cortex) is damaged, forced utilization can be seen. When objects are placed in front of a subject with frontal damage, the subject will pick them and start using them even when the subject is instructed not to use them.

Question 48

Obstruction to CSF circulation leads to non-communicating hydrocephalus. The cerebrospinal fluid passes into the subarachnoid space via recesses in which of the following structures?

Select one:
1. Lateral ventricle
2. First ventricle
3. Fourth ventricle
4. Third ventricle
5. Aqueduct of sylvius

Answer 48

Fourth ventricle

CSF is secreted by the choroid plexus in the lateral, third and fourth ventricles and at a rate of 300 ml/day,
which is almost protein free. It passes into the subarachnoid space via recesses in the fourth ventricle- Foramina of Magendie and Foramina of Luschka.
Obstruction to its circulation commonly occurs within third or fourth ventricle, leading to non-communicating hydrocephalus. Obstruction to CSF flow in the subarachnoid space leads to communicating or normal pressure hydrocephalus.

Circulation of CSF:
1. From lateral ventricle to 3rd ventricle- via Interventricular foramina of Monro
2. From 3rd to 4th Ventricle- via cerebral aqueduct of Sylvius
3. From 4th ventricle to subarachnoid space via Foramen of Magendie (single medial foramen) and
Foramen of Luschka (two, lateral foramina)

Question 49

Mr. Y developed normal pressure hydrocephalus following trauma in the basal brain. The obstruction is
most likely to have occurred in the;

Select one:
1. Foramen of Luschka
2. Foramen of Munro
3. Cisterna Magna
4. Arachnoid granulations
5. Foramen of Magendie

Answer 49

Foramen of Munro

The question indicates that there is an obstruction. If there is an obstruction after trauma, this is likely to be
at Foramen of Monro. A number of cases will have non-obstructive form, where arachnoid villi are
implicated.

Posttraumatic hydrocephalus (PTH) is a frequent and serious complication that follows a traumatic brain
injury. PTH may present as normal pressure hydrocephalus (NPH, no increase in intracranial pressure) or as a syndrome of increased intracranial pressure due to either communicating or noncommunicating hydrocephalus. In noncommunicating hydrocephalus (obstructive hydrocephalus), CSF accumulates in the ventricles because of CSF flow blockage. As a result, the ventricles enlarge and the hemispheres expand.
The commonest site of block in non-communicating hydrocephalus is foramen of Monroe. Other sites
include; Third ventricle, Aqueduct of Sylvius, Fourth ventricle, Foramen of Luschka and Foramen of
Magendie. Impaired CSF absorption may cause communicating hydrocephalus. The apparent mechanism is partial occlusion of the arachnoid villi in this case.

Question 50

The ventral tegmental area is located in which part of the brain?

Select one:
1. Midbrain
2. Occipital lobe
3 .Pons
4. Medulla
5. Temporal lobe

Answer 50

Midbrain

The ventral tegmentum is located in the midbrain and contains dopaminergic cells that give rise to the
mesolimbic dopamine pathway. This pathway is crucial for reward and sensations of pleasure.

Question 51

Which of the following structures divide the frontal lobe from the temporal lobe?

Select one:
1. Central sulcus
2. Lateral sulcus
3. Cingulate gyrus
4. Calcarine fissure
5. Superior temporal gyrus

Answer 51

Lateral sulcus

The lateral sulcus (also called Sylvian fissure or lateral fissure) is a prominent landmark of the human brain.
It divides the frontal lobe and parietal lobe from the temporal lobe.

Question 52

Mirror neurons are found in which part of the brain?

Select one:
1. Inferior parietal lobe
2. Lateral frontal cortex
3. Medial-dorsal frontal cortex
4. Medial temporal lobe
5. Inferior frontal cortex

Answer 52

Inferior frontal cortex

Functional magnetic resonance imaging studies reveal activity of the inferior frontal and superior parietal
cortices both during the performance of an action, and the observation of other person performing the same
action. These brain regions supposedly contain mirror neurons, which explain why we imitate activity that
we observe (modelling). For example while watching sports like tennis the sports fans may feel so
emotionally involved in the game and react almost as if they were part of the game themselves. This
behavior is explained by the presence of mirror neurons in our brain.

Question 53

Which of the following structures give rise to cerebral hemispheres during embryogenesis?

Select one:
1. Myelencephalon
2. Diencephalon
3. Mesencephalon
4. Metencephalon
5. Telencephalon

Answer 53

Telencephalon

Telencephalon gives rise to cerebral hemispheres and contains the pallium, rhinencephalon, and basal
ganglia

Question 54

Which structure separates the two lateral ventricles in the human brain?

Select one:
1. Septum pellucidum
2. Pons
3. Aqueduct of sylvius
4. Septum pallidum
5. Corpus callosum

Answer 54

Septum pellucidum

The body of the lateral ventricle lies immediately below the corpus callosum and they are separated by
septum pellucidum. An anomalous splitting of the septum pellucidum may be more common in
schizophrenia than in general population (cavum septum pellucidum). The third ventricle lies between
thalamus and hypothalamus. The fourth ventricle lies above the pons and just below the cerebellum. The
Aqueduct of Sylvius links the third and fourth ventricles.

Question 55

In which area of the brain is the dentate gyrus located?

Select one:
1. Hippocampus
2. Hypothalamus
3. Dorsolateral prefrontal cortex
4. Amygdala
5. Red nucleus

Answer 55

Hippocampus

The dentate gyrus is part of the hippocampal formation. It is thought to contribute to the formation of new episodic memories. It is currently known to have high rates of neurogenesis in animal experiments using adult rats

Question 56

Nucleus accumbens forms a part of which of the following structures of the brain?

Select one:
1. Hypothalamus
2. Ventral striatum
3. Pineal gland
4 .Dorsal region of thalamus
5. Orbitofrontal cortex

Answer 56

Ventral striatum

The nucleus accumbens is a collection of neurons and forms the main part of the ventral striatum, located
proximal to the head of the caudate nucleus and the anterior portion of the putamen.

Question 57

Which one of the following cells is considered as descendants of macrophages that clear neuronal debris following cell death?

Select one:
1. Microglial cells
2. Ependymal cells
3. Schwann cells
4. Astrocytes
5. Oligodendrocytes

Answer 57

Microglial cells

The microglia are descendants of macrophages. They are scavenger cells, which clear neuronal debris
following cell death.

Question 58

Which one of the following structures is involved in the visual pathway?

Select one:
1. Medial geniculate body
2. Heschl’s gyrus
3. Inferior Colliculus
4. Lateral geniculate body
5. Tegmentum

Answer 58

Lateral geniculate body

The medial fibres of the optic nerve cross in the optic chiasma to join the contralateral optic tract. The
lateral fibres of the optic nerve pass through the ipsilateral optic tract. The fibres synapse in the lateral
geniculate body of the thalamus. From here the optic radiation runs within the posterior part of the internal
capsule and terminates in the visual cortex. Myers loop is part of the optic radiation, which loops anteriorly from the lateral geniculate ganglion into the temporal lobe before travelling posteriorly in the occipital cortex

Question 59

A lesion affecting which of the following structures can cause dysarthria?

Select one:
1. Homunculus
2. Parietal lobe
3. Temporal lobe
4. Cerebellum
5. Spinal cord

Answer 59

Cerebellum

Dysarthria refers to speech that is characteristically slurred, slow, and difficult to understand. It is caused by upper motor neurone lesions of the cerebral hemispheres or lower motor neurone lesions of the brain stem. It also results from disruption to the integrated action of upper motor neurones, basal ganglia and cerebellum.

Question 60

The foramen of Monro connects

Select one:
1. Fourth ventricle to subarachnoid space
2. Lateral ventricle to third ventricle
3. Fourth ventricle to central canal of spinal cord
4. Lateral ventricle to fourth ventricle
5. Lateral ventricle to second ventricle

Answer 60

Lateral ventricle to third ventricle

The foramen of Monro (also known as the interventricular foramen) is part of the ventricular system and the connection between the third ventricle and the lateral ventricles. It allows for the flow of CSF, and, therefore, if blocked or effaced, causes a reduction in CSF flow from the lateral ventricles despite no associated reduction in CSF production from the choroid plexus.

Question 61

Which of the following is correct with respect to cerebral dominance?

Select one:
1. Most left handed individuals have bilateral dominance
2. Most left handed individuals have right cerebral dominance
3. Most left handed individuals have left cerebral dominance
4. Right handed individuals always have right cerebral dominance
5. Dominance cannot be ascertained in left handed individuals

Answer 61

Most left handed individuals have left cerebral dominance

In 10% of right-handed people, the right hemisphere is dominant. In left handed people only about 20% are
right hemisphere dominant as expected, with 64% left hemisphere dominant and 16% showing bilateral
dominance.

Question 62

Which part of the brain is associated with aura in epilepsy?

Select one:
1. Frontal lobe
2. Pre central gyrus
3. Occipital lobe
4. Temporal lobe
5. Parietal lobe

Answer 62

Temporal lobe

The early warning symptoms of a seizure are called aura; these are due to the onset of the seizure activity
in a circumscribed part of the temporal lobe. The aura may stop without further spreading, or go on to
spread resulting in generalisation and altered consciousness. The temporal lobe is involved in consolidating memories and processing emotions; seizures in this area may begin with feelings of fear, feelings of joy, recall of certain music, smells, and other unusual symptoms.

Question 63

Hippocampus is supplied by

Select one:
1. Posterior choroidal artery
2. Posterior cerebral artery
3. Posterior inferior cerebellar artery
4. Middle cerebral artery
5. Anterior cerebral artery

Answer 63

Posterior cerebral artery

The hippocampal arteries mainly arise from posterior cerebral artery and to a lesser extent from the anterior
choroidal artery.

Question 64

Which of the following constitute the most common cells of the layer 4 of the cerebral cortex that receives
thalamic input?

Select one:
1. Large pyramidal cells
2. Stellate cells
3. Horizontal cells of cajal
4. Glial cells
5. Small Pyramidal cells

Answer 64

Stellate cells

The cerebral cortex is stratified into six layers. The most common cells are pyramidal cells, which are
present in all the layers except layer 1 where their dendrites form a tuft.

Layer 1 contains no major neuronal cell bodies but glial cells and dendrites from neurones of deeper layers and the horizontal cells of Cajal.

Layers 2 and 3 are composed of small pyramidal cells, whose axons project out of and within the
hemispheres. Stellate and fusiform cells lie in layer 4 and provide local connections and receive ascending fibres from the thalamus.

Layer 5 consists of large pyramidal cells. The cerebellar cortex is three layered.The molecular layer consisting of basket cell and stellate cell, Purkinje layer consisting of Purkinje cell anda granular layer consisting of granule and Golgi cell.