review

Question 1

The parotid gland
a) Is separated from the submandicular gland by the stylomandibular ligament
b) Is related anteriorly to the lateral pterygoid
c) Has the ECA running superficial to the facial nerve within its substance
d) Receive secretomotor fibres from the facial nerve

Answer 1

A. the “only thing separating the parotid gland from the submandibular gland is the stylomandibular ligament”, which is a thin condensation of the parotid gland’s fascial sheath. This is clinically significant because it makes it difficult to determine the source of swelling in this area.

Question 2

The medial pterygoid muscle:
a) Is not attached to the lateral pterygoid plate of the sphenoid bone
b) Attached to the maxillary tuberosity
c) Innervated by the buccal nerve

Answer 2

B. The maxillary tuberosity gives origin to a few fibres of the medial pterygoid muscle.

Question 3

Which of the following is false regarding the TMJ?
a) Lateral ligament is taut when the jaw is elevated
b) Is a condyloid joint
c) Has tendon of the medial pterygoid muscle attached to the fibrocartilaginous disc
d) Has the chorda tympani nerve as a posterior relation

Answer 3

Option C: False. It is the tendon of the lateral pterygoid muscle that attaches to the fibrocartilaginous disc, not the medial pterygoid.

Question 4

The ophthalmic artery:
a) arises from the internal carotid soon after if pierces the dura and enters the subarachnoid space
b) enters the orbit through the superior orbital fissure
c) Passes from medial to lateral over the optic nerve as these structures pass anteriorly through the orbit
d) Terminates by dividing into supraorbital and infratrochlear branches

Answer 4

A
Option A: True! After coursing through the cavernous sinus, the ICA pierces through the dural wall of the sinus to enter the subarachnoid space. It then gives off its first branch - the ophthalmic artery, which runs with the optic nerve and ophthalmic vein into the orbit.
Option B: False, the ophthalmic artery enters the SOF via the Optic Canal.
Option C: False. Referring to the diagram (of the right eye), the ophthalmic artery passes beneath the optic nerve from lateral to medial.
Option D: False, it terminates by dividing into supraorbital and supratrochlear branches.

Question 5

In the lacrimal apparatus:
a) The lacrimal gland is innervated by the zygomaticotemporal nerve
b) The gland is superficial to the orbicularis oculi muscle
c) Removal of tears is entirely by evaporation from the exposed surface of the eyeball
d) The nasolacrimal duct descends between the maxillary bone and the middle concha

Answer 5

A

Question 6

11. Destruction of which cranial nerve would result in the inability to masticate food?
    a. V
    b. VI
    c. VII
    d. IX

Answer 6

A. Muscles of mastication are innervated by CN V3. These include the masseter, temporalis, as well as the medial and lateral pterygoid muscles.

Question 7

14. Bundles of axons or nerve fibers are known as tracts, except in the PNS, where they are known as:
    a. ganglia
    b. interneurons
    c. nuclei
    d. nerves
    e. postsynaptic neurons

Answer 7

D.

A: Ganglia are aggregations of cell bodies in the PNS.
B: Interneurons are singular nerves connecting sensory neurons to motor neurons, mostly found in the grey column of the spinal cord.
C: Nuclei are aggregations of cell bodies in the CNS.
E: ‘Postsynaptic neurons’ is a very broad term. Anyway, neurons are single cells, and bundles of axons or nerve fibres are not going to be found in single cells.

Question 8

16. The part of the brain responsible for the regulation of body temperature and hunger is the:
    a. superior colliculus
    b. parietal lobe
    c. epithalamus
    d. medulla oblongata
    e. hypothalamus

Answer 8

Option E: Factual. According to Prof Ng Yee Kong’s slides, the hypothalamus is also responsible for endocrine control (via releasing/inhibitory hormones), neurosecretion (eg oxytocin/ADH), thermoregulation, regulation of food and water intake, sexual behavior, reproduction, acting as head ganglion of the ANS, a biological clock and part of the limbic system.

Question 9

18. Which of the following statements about the spinal cord is true?
    a. it extends from the foramen magnum to the level of S1
    b. it is located in the central canal
    c. both ascending and descending fiber tracts are present
    d. it consists of a central area of white matter, surrounded by gray matter
    e. two of the above

Answer 9

C

Option A: It extends from foramen magnum to L1/L2 and not S1.
Option B: It is located in the vertebral canal, which is formed from the vertebral foramen of the vertebrae. It is CSF that is located in the central canal.
Option C: Factual.
Option D: The spinal cord is made up of gray matter surrounded by white matter.

Question 10

The cell bodies of postganglionic autonomic fibers are located in:
A. the lateral horn of the spinal cord (1st)
B. the effector organ
C. the ventral horn of the spinal cord
D. the medulla oblongata
E. ganglia

Answer 10

E. The cell bodies of postganglionic autonomic fibres are located in various ganglia, and are always outside the CNS

Question 11

The cell bodies of preganglionic parasympathetic neurons are located in the:
A. cervical and thoracic spinal cord
B. brain and lumbar spinal cord
C. thoracic and lumbar spinal cord
D. brain and sacral spinal cord

Answer 11

D.
Option D: Factual. That’s why the parasympathetic system is said to have “craniosacral outflow”.

Question 12

The hormone melatonin is produced by the:
A. pituitary gland
B. hypothalamus
C. epithalamus
D. medulla oblongata
E. none of the preceding

Answer 12

Option C: Melatonin is produced by the pineal gland of the epithalamus.

Question 13

The _____ separates the two cerebellar hemispheres.
A)falx cerebelli
B)falx cerebri
C)tentorium cerebelli
D)arachnoid meninx

Answer 13

Option A: Factual and derivable from the name! It is a sickle-shaped (falx = sickle) fold of dura mater that separate the cerebellar hemispheres (cerebelli refers to cerebellum).

Question 14

At what level do the majority of nerve fibers cross from the right to the left?
A)T1-T12
B)medulla
C)pons
D)cervical region of spinal cord

Answer 14

Option B: The medulla is the site of decussation of all DCML fibres and nearly all corticospinal fibres.

Question 15

Initially, the developing forebrain is called the _____.
A)prosencephalon
B)diencephalon
C)telencephalon
D)rhombencephalon

Answer 15

Option A: Factual. Brief embryology: the brain is divided into 3 primary portions during early development: the prosencephalon (forebrain), mesencephalon (midbrain) and rhombencephalon (hindbrain). Eventually, this develops into a 5-ventricle stage when the forebrain separates into the telencephalon (cerebrum) and diencephalon (hypothalamus, thalamus, epithalamus), and the hindbrain separates into the metencephalon (pons and cerebellum) and myelencephalon (medulla). The mesencephalon remains as the midbrain.

Question 16

The cerebral hemispheres are connected by a large white fiber pathway called the _____.
A)fornix
B)insula
C)circular sulcus
D)corpus callosum

Answer 16

Option D: Factual. In fact, the corpus callosum is the largest type of commissural fibre (fibres that connect the two hemispheres of the brain).

Question 17

Broca’s area is usually in the _____ area of the _____.
A)left; prefrontal cortex
B)right; temporal lobe
C)left; frontal lobe
D)right; occipital lobe

Answer 17

Option C: Factual. In particular, it is noteworthy that Broca’s is only located unilaterally (usually in the left hemisphere). This phenomenon where certain neural functions are more dominant on or even exclusively located on one hemisphere is known as “lateralization”. For Broca’s, a correlation to handedness is also exhibited (eg. right handed people have Broca’s on their left hemispheres, and vice versa for left handed people)

Question 18

Pyramidal cells are located in the _____ region.
A)cerebellar
B)cerebral cortex
C)corpus callosum
D)basal ganglia

Answer 18

Option B: A pyramidal cell is a type of neuron that is found in forebrain structures like the cerebral cortex, hippocampus and amygdala. It is named as such due to its pyramidal (triangular)-shaped cell body.

Question 19

The interventricular foramen connects the _____.
A)two lateral ventricles
B)lateral to fourth ventricle
C)lateral to third ventricle
D)third to fourth ventricle

Answer 19

C.
The interventricular foramina (of Monro) connect the lateral ventricles to the third ventricles. Do not confuse this with the medial foramen (of Magendie) or the lateral foramina (of Luschka) which connect the fourth ventricle to the subarachnoid space.

Question 20

The third ventricle is located around and near the _____.
A)hippocampus
B)thalamus
C)cerebellum
D)midbrain

Answer 20

Option B: The third ventricle is located in the diencephalon, and the thalamus is part of the diencephalon. (Meanwhile, the lateral ventricles are in the telencephalon (i.e. cerebrum), and 4th ventricle is in the metencephalon (i.e. between pons and cerebellum).

Question 21

On the average, nearly _____ ml of CSF are produced daily.
A)100
B)500
C)140
D)1,000

Answer 21

b

Question 22

The infundibulum is a narrow part of the _____.
A)hypothalamus
B)pituitary
C)pineal gland
D)thalamus

Answer 22

B

Question 23

Sensory impulses are screened and relayed to higher centers by the _____ region.
A)thalamus
B)hypothalamus
C)mammillary body
D)limbic system

Answer 23

Option A: The thalamus acts as a “relaying centre” which receives sensory, motor and cognitive information, integrates it, and then “sends” it on to reach the sensory and motor cortices. (Btw it also regulates consciousness and sleep)

Question 24

The area that coordinates visual reflexes is the _____.
A)cerebellum
B)superior colliculus
C)inferior colliculus
D)cerebral peduncles

Answer 24

B

Option B: Factual (in particular, it is involved in the accommodation-convergence reflex). (But a good trick question! Note that inferior colliculus is involved in the auditory pathway, while superior colliculus is involved in the visual pathway.)
Option D (if you’re interested): the cerebral peduncles are a part of the midbrain that link the remainder of the brainstem to the thalamus (and from there, the cerebrum). They assist in refining motor movements, learning of new motor skills, and converting proprioceptive
information into balance and posture maintenance

Question 25

The _____ has the main centers for breathing reflexes.
A)pons
B)medulla
C)cerebrum
D)hypothalamus

Answer 25

Option B: Factual, the medulla is the location of the “vital centres” responsible for
vital functions like breathing

Question 26

Which of the following is not a medullary vital center?
A)blood pressure
B)cardiac
C)vasomotor
D)respiratory

Answer 26

A
Option A: There is no such thing as a “blood pressure centre”. Rather, blood pressure is regulated by the “vasomotor centre”.
Options B-D: The medulla is indeed to have these 3 vital centres: cardiac (regulates heart rate via ANS fibres to the sinuatrial node), respiratory centre (regulates rate and depth of ventilation) and vasomotor centre (modulates ANS to regulate blood pressure, e.g. by changing blood vessel diameter). An injury to the medulla is thus most likely fatal.

Question 27

The longest autonomic nerve is the _____.
A)phrenic
B)spinal accessory
C)vagus
D)thoracic

Answer 27

C

Question 28

Sympathetic nerves arise from _____ and _____ regions.
A)cervical; lumbar
B)cranial; sacral
C)cranial; thoracic
D)thoracic; lumbar

Answer 28

Option D: That’s why the sympathetic system is said to have “thoracolumbar outflow”.

Question 29

Norepinephrine is released from _____ nerves.
A)all autonomic
B)parasympathetic
C)the vagus
D)sympathetic

Answer 29

Option D: Norepinephrine is a neurotransmitter of nearly all post-ganglionic sympathetic nerves (Except those of sweat glands)

Question 30

When a person thinks and solves problems, which area of the cerebrum is involved?
A)frontal lobe
B)parietal lobe
C)occipital lobe
D)temporal lobe (1st)

Answer 30

Option A: Factual

Question 31

The connection between the third and fourth ventricle is called the _____.
A)interventricular foramen
B)cerebral aqueduct
C)foramen of Monro
D)hypothalamus

Answer 31

B

Question 32

The centers that control vital visceral activities are located within the _______ area of the brain.
A)hypothalamus
B)cerebral cortex
C)pons
D)medulla oblongata

Answer 32

D
The correct answer to the question about which area of the brain controls vital visceral activities is D) medulla oblongata. Here’s why:

1. Autonomic Functions: The medulla oblongata is responsible for regulating several critical autonomic functions, including heart rate, blood pressure, and respiration. It contains vital centers such as the cardiovascular center and the respiratory center, which are essential for maintaining homeostasis in the body[1][2][4].
2. Connection to the Spinal Cord: The medulla serves as a conduit between the brain and the spinal cord, allowing for the integration of autonomic functions with higher brain activity. This connection is crucial for reflex actions that involve visceral organs[3][4].
3. Reflex Centers: In addition to regulating basic physiological functions, the medulla also houses reflex centers for actions such as vomiting, coughing, sneezing, and swallowing. These reflexes are vital for protecting the body and maintaining internal stability[2][5].

In contrast, while the hypothalamus also plays a significant role in regulating visceral activities by influencing autonomic functions and hormone release, the direct control of basic life-sustaining functions like respiration and cardiovascular regulation primarily resides in the medulla oblongata. Therefore, option D is indeed correct.

Question 33

Which brain area acts to regulate body temperature?
A)thalamus
B)cerebrum
C)hypothalamus
D)cerebellum

Answer 33

C

Question 34

Which brain area acts to screen all incoming sensory data except for smell?
A)cerebral cortex
B)medulla
C)cerebellum
D)thalamus

Answer 34

Option D: an interesting fact! The thalamus does indeed screen all sensory info except for smell; olfaction is processed by the limbic system instead (which may explain smell is most strongly linked to strong emotions and/or memories)

Question 35

The image focused on the blind spot lies in which area of the visual axis?
a. In the visual axis
b. Medial to the visual axis
c. Superior to the visual axis
d. Inferior to the visual axis
e. Lateral to the visual visual axis

Answer 35

Option B: Factual. Note that “blind spot” refers to the position of the optic disk at which there are no photoreceptors. Lateral to the blind spot is the fovea centralis, which contains a high concentration of cones and where visual acuity is thus very high. Since the “visual axis” is defined as a straight line passing from the object through the pupil to reach the centre of the fovea (which thus gives the best colour vision), the blind spot thus ends up medial to the visual axis.

Question 36

Profuse bleeding from the scalp is from which of the following?
a. Epidermis from the skin
b. Occipitofrontalis aponeurosis
c. Subcutaneous tissue
d. Loose areolar tissue
e. Pericardium

Answer 36

Option C: The dense subcutaneous tissue layer is actually the site of the superficial blood vessels of the scalp. Profuse bleeding is thus most likely to originate from a lesion in this layer.

Question 37

The accommodation of the eye involves the following except:
a. Ciliary ganglion
b. Medial rectus muscle
c. Ciliary muscle
d. Oculomotor nerve
e. Lateral rectus

Answer 37

Option E: Lateral rectus abducts the eye – an action that is irrelevant to accommodation. (When focusing on an object that’s moving nearer, you are obviously more likely to adduct rather than abduct your eyes!)

Question 38

Anterior cranial fossa fracture is least likely to cause
a. Bleeding into orbit
b. Bleeding from nose
c. Loss of smell
d. Leaking of cerebrospinal fluid from nose
e. Loss of vision

Answer 38

E

E: Loss of vision is unlikely because the optic nerve is well protected by orbital fat within the orbit, and it travels through the optic canal which is in the middle cranial fossa.
A & B: If the floor of the anterior cranial fossa is fractured, there will be a large communication between the anterior cranial fossa and the orbit, or between the anterior cranial fossa and the nasal cavity. This could mean that blood or CSF from the anterior cranial fossa (as a result of torn meninges associated with the fracture) could leak into the orbit and nasal cavity.
C: The fracture can involve the cribriform plate where the olfactory nerve runs through, and this can result in anosmia – the loss of smell.
D: The bone fragments can tear through the meningeal coverings, resulting in the leaking of CSF from the nose. This is known as CSF rhinorrhea, and this is dangerous because it means that there is a communication from the external environment to the brain and extreme precautions must be made to prevent infection.

Question 39

Occlusion of the left middle cerebral artery may lead to the following except:
A) Contralateral hemiparesis of the face
B) Contralateral hemisensory deficit of the arm
C) Contralateral hemiplegia of the leg
D) Dressing apraxia
E) Expressive (Broca’s) aphasia

Answer 39

Option C: According to the Motor Homunculus, the lower limb is located on the medial surface of the pre-central gyrus, which is supplied by the ACA. An occlusion of the MCA will thus not cause this.
Options A, B: The superior division of the MCA supplies motor and sensory function to areas of pre and post-central gyri that correspond to the face and arms.
D: Dressing apraxia (D) is an inability to put on clothes. Apraxia is usually due to a lesion of the frontal and parietal lobes of the dominant (usually left) hemisphere of the brain, which is supplied by the inf division of the MCA.
E: Expressive (Broca’s) aphasia is caused by a lesion of the Broca’s area, which is in the posterior part of the frontal lobe on the dominant hemisphere of the brain. It is supplied by the sup division of the MCA. Expressive aphasia may therefore occur following occlusion of the left middle cerebral artery.

Question 40

Lesion of the cerebellum may lead to the following except:
A) Altered walking gait
B) Ipsilateral uncoordinated movements of the hand
C) Contralateral hemiparesis
D) Dysmetria
E) Dysdiadochokinesia

Answer 40

Option C: Contralateral hemiparesis (one-sided weakness) is a symptom of a lesion to the pre-central gyrus instead. Lesion of the cerebellum will not cause contralateral hemiparesis because the cerebellum is not responsible for initiating movements.

Question 41

These can be surgically accessed in the posterior triangle of the neck except
A) Apex of lung
B) Brachial Plexus
C) Vagus Nerve
D) Phrenic Nerve
E) Subclavian Artery

Answer 41

Option C: The vagus nerve isn’t considered to be located in the posterior triangle of the neck.