Neuroanatomy

Question 1

What deficits will a stroke of the anterior cerebral artery cause?

Answer 1

A stroke of the anterior cerebral artery will cause deficits in movement, cutaneous sensations, and executive functions.

Question 2

What deficits will a stroke of the middle cerebral artery cause?

Answer 2

A stroke of the middle cerebral artery will cause deficits in language, hearing, movement, and executive functions.

Question 3

What deficits will a stroke in the posterior cerebral artery cause?

Answer 3

A stroke of the posterior cerebral artery will cause deficits in vision.

Question 4

Cranial Nerve I

Answer 4

Olfactory Nerve
Origin: Nasal Mucosa
Supply: Conveys the sense of smell
Sensory
Clinical Correlates: Amnosia

Question 5

Cranial Nerve II

Answer 5

Optic Nerve
Origin: Retina
Supply: Conveys visual information towards the cortex
Sensory
Clinical correlates: Visual deficits, pupillary light reflex deficits

Question 6

Cranial Nerve III

Answer 6

Ocularmotor Nerve
Motor
Origin: Midbrain
Supply: Extraocular muscles, sphincter pupilae muscle, and ciliary muscle
Clinical Correlates: Pupillary light reflex, acommodation reflex, strabismus, ptosis (drooping eye), and diplopia (double vision)

Question 7

Cranial Nerve IV

Answer 7

Trochlear Nerve
Origin: Midbrain
Supply: Motor innnervation to the superior oblique muscle of the eye
Motor
Clinical correlates: Diplopia (Double Vision)

Question 8

Cranial Nerve V

Answer 8

Trigeminal Nerve
Mixed (Sensory & Motor)
Origin: Pons
Sensory Root Supply: Sensory innervation from the forehead and face, paranasal sinuses, nasal and oral cavities, and the anterior two thirds of the tongue
Motor Root Supply: Motor innervation to the muscles of mastication
Clinical Correlates: Corneal reflex, trigeminal neuralgia (acute paroxysmal pain radiating along the course of one of more nerves)

Question 9

Cranial Nerve VI

Answer 9

Abducens Nerve
Motor
Origin: Ventral surface of the pons
Supply: Motor innervation to the lateral rectus muscle of the eye
Clinical Correlates: Diplopia (double vision), strabismus (eyes do not line up in the same direction)

Question 10

Cranial Nerve VII

Answer 10

Facial Nerve
Mixed (Sensory & Motor)
Origin: Ventrolateral pontomedullary junction
Sensory Root Supply: Conveys taste from the anterior two-thirds of the tongue and general sensation from the external ear
Motor Root Supply: Innervates all muscles of facial expression
Clinical Correlates: Bell’s palsy, loss of taste, reduced salivation, hyperacusis (noise sensitivity), dry eye, corneal reflex

Question 11

Cranial Nerve VIII

Answer 11

Vestibulochochlear Nerve
Sensory
Origin: Pons
Supply: Special sensory innervation, carrying sensory information for hearing and balance
Clinical Correlates: Vertigo, nystagmus (involuntary eye movements), disequilibrium, deafness

Question 12

Cranial Nerve IX

Answer 12

Glossapharyngeal Nerve
Mixed (Sensory & Motor)
Origin: Medulla oblongata of the brainstem
Sensory root supply: Tympanic cavity, auditory tubes, oropharynx, the external ear, posterior one-third of the tongue (both general sense and taste)
Motor root supply: Stylopharyngeus muscle
Clinical correlates: Gag reflex

Question 13

Cranial Nerve X

Answer 13

Vagus Nerve
Mixed (Sensory & Motor)
Origin: Medulla oblongata of the brainstem
Sensory Root Supply: General sensation from portions of the external ear, baro- and chemo-receptors on the aortic arch, and taste sensations on the epiglottis region
Motor Root Supply: Muscles of the palate, pharynx, and larynx
Clinical Correlates: Gag reflex, hoarseness, cough reflex, sleep apnea, bradycardia, hypotension, vagal nerve stimulations

Question 14

Cranial Nerve XI

Answer 14

Accessory Nerve
Motor
Origin: Medulla oblongata of the brainstem
Supply: Motor innervation of the sternocleidomastoid and trapezius muscles
Clinical Correlates: None

Question 15

Cranial Nerve XII

Answer 15

Hypoglossal Nerve
Motor
Origin: Medulla oblongata
Supply: Motor innervation to all the muscles of the tongue, except palatoglossus muscle
Clinical correlates: Dysarthia (slurred speech), obstructive sleep apnea

Question 16

What is the anatomical location and the function of the basilar artery?

Answer 16

The basilar artery is an unpaired artery that is on the ventral aspect of the pons in the brainstem. The basilar artery and its branches provide an arterial supply to the cerebellum, brainstem, and the posterior part of both cerebral hemispheres.

Question 17

What is the anatomical location and the function of the vertebral arteries?

Answer 17

The vertebral arteries are paired arteries that are on the ventral aspect of the medulla. The vertebral arteries merge to form the basilar arteries. The vertebral arteries supply the upper spinal cord and the cerebellum.

Question 18

What is the anatomical position and the function of the pontine arteries?

Answer 18

The pontine arteries are a number of small vessels that arise from the basilar artery. The pontine arteries provide an arterial supply to the pons and adjacent parts of the brain.

Question 19

What are the anatomical positions and functions of the posterior cerebral arteries?

Answer 19

The posterior cerebral arteries are the terminal branches of the basilar artery that supply arterial blood to the posterior part of the cerebrum. The posterior cerebral arteries are joined with the anterior and middle cerebral arteries in an arterial ring called the circle of Willis.

Question 20

What are the anatomical positions and the functions of the internal carotid arteries?

Answer 20

The internal carotid arteries travel superior to the base of the skull and enter the cranial cavity where each divide into an anterior cerebral artery and a middle cerebral artery. The internal carotid arteries and their branches provide an arterial supply to the structures of the interior of the cranium including the brain and the pituitary gland.

Question 21

What are the anatomical positions and the functions of the anterior cerebral arteries?

Answer 21

The anterior cerebral arteries are one of two terminal branches of the carotid arteries, the others being the middle cerebral arteries. The anterior cerebral arteries and their branches provide an arterial supply to the frontal and parietal lobes, corpus callosum, and structures of the diencephalon.

Question 22

What is the anatomical position and the function of the anterior communicating artery?

Answer 22

The anterior communicating artery is a single anastomosic vessel that arises from and connects both the right and left anterior cerebral arteries. It forms a part of the circle of Willis.

Question 23

What is the anatomical structure and function of the circle of Willis?

Answer 23

The circle of Willis (CoW) is a ring of vessels connecting the anterior and posterior circulations of the brain. The structural components of the circle of Willis are the following: anterior communicating artery (ACom), bilateral anterior cerebral arteries (ACAs), internal carotid arteries (ICAs), middle cerebral arteries (MCAs), bilateral posterior communicating arteries (PCAs), and the posterior cerebral arteries (PCAs). The CoW provides anastomotic connection (a cross-connection between the adjacent arterial systems in the brain) between the anterior and posterior circulations by providing collateral blood flow to affected brain regions in the event or arterial incompetency.

Question 24

What is the anatomy of the vertebral column?

Answer 24

The vertebral column (also known as the spine or spinal column) consists of 33 vertebrae organized in 5 regions. The regions are cervical, thoracic, lumbar, sacral, and coccygeal. There are 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 sacral vertebrae, and 4 coccygeal vertebrae.

Question 25

How many cranial nerves have both a sensory and a motor root, and which nerves are they?

Answer 25

There are four cranial nerves that are mixed (have both a sensory and motor root). The following are the mixed cranial nerves: - CN V (Trigeminal Nerve) - CN VII (Facial Nerve) - CN IX (Glossopharyngeal Nerve) - CN X (Vagus Nerve)

Question 26

What is the functional neuroanatomy of the basal ganglia?

Answer 26

The “basal ganglia” refers to a group of telencephalic subcortical nuclei responsible primarily for motor control, as well as other roles such as motor learning, executive functions and behaviors, and emotions. The major function of the basal ganglia to to modulate the motor cortex and thereby contribute to the selection of voluntary movements.

Question 27

What is the functional neuroanatomy of the dorsal column (DC)?

Answer 27

The functional neuroanatomy of the dorsal column (DC) also known as the dorsal column medial lemniscus (DCML) pathway, is to convey sensory information regarding fine touch, two-point discrimination, conscious proprioception, and vibration sensations to the post central gurus in the cerebral cortex from skin and joints, excluding the head. The DCML tract decussates in the brainstem at the level of the medulla.

Question 28

What is the functional neuroanatomy of the spinothalamic tract (ST)?

Answer 28

The functional neuroanatomy of the spinothalamic tract (ST) is to convey information regarding pain and temperature from the skin to the somatosensory area of the thalamus. The spinothalamic tract decussates at the level of the spinal cord.

Question 29

What is the functional neuroanatomy of the spinocerebellar tracts (SCs)?

Answer 29

The functional neuroanatomy of the spinocerebellar tracts (SCs) is to carry unconscious proprioceptive information from the trunk and limbs of the body to the cerebellum.

Question 30

What is the functional neuroanatomy of the lateral corticospinal tract?

Answer 30

The functional neuroanatomy of the lateral corticospinal tract is to convey information from the motor cortex to the muscles of the limbs and digits in order to initiate movement of those muscles. The corticospinal tract decussates in the brainstem at the level of the medulla.

Question 31

What is the functional neuroantomay of the anterior (or medial) cortiospinal tract?

Answer 31

The functional neuroanatomy of the anterior (medial) corticospinal tract is to convey information from the motor cortex to the muscles of the trunk in order to initiate movement of those muscles.

Question 32

What is the internal capsule?

Answer 32

The internal capsule (IC) is a subcortical white matter structure situated in the inferomedial portion of each cerebral hemisphere. Most of the axonal fibers leave or enter the thalamus, but the interval capsule also contains aconal fibers that project directly from the cortex to the brainstem (i.e. corticobulbar axons) and to the spinal cord (i.e. corticospinal axons).

Question 33

What is hemotympanum?

Answer 33

Hemotympanum is blood in the middle ear, a finding sometimes identified in serious traumatic brain injury.

Question 34

What is the cavernous sinus?

Answer 34

The cavernous sinus is a rural sinus found along the sides of the sella Turkic a in the middle cranial fossa. It is drained by the inferior and the superior petrosal sinuses. The right and left cavernous sinuses are connected by the anterior and the posterior inter cavernous sinus. Tributaries of the cavernous sinus include the superior ophthalmic, superficial middle cerebral, and inferior cerebral arteries veins and the sphenoparietal sinuses.

Question 35

What is Broca’s area?

Answer 35

Broca’s area is the area of the left hemisphere of the brain at the posterior end of the inferior frontal gurus. It contains the motor speech area and controls movement of tongue, lips, and vocal cords. Loss of speech may follow any stroke affecting this area.

Question 36

What is the Wernicke area, and what Wernicke aphasia?

Answer 36

The Wernicke area is the area in the dominant hemisphere of the brain that recalls, recognizes, and interprets words and other sounds in the process of using language. ‘ Wernicke aphasia is an injury to the Wernicke area in the temporal lobe of the dominant hemisphere of the brain, resulting in an inability to comprehend the spoken or written word. Visual and auditory pathways are unaffected, but patients are unable to differentiate between words or interpret their meaning. The disorder is often caused by impairment of blood flow through the lower division of the left middle cerebral artery.

Question 37

What is the angular gyrus?

Answer 37

The angular gyrus is a gyrus of the ventral region of the parietal lobe. It us just ventral to the supranational gyrus and caps the posterior (ascending) end of the superior temporal sulcus. The correct of the angular gyrus plays a role in the association of the visual and tactile perceptions of forms and shapes.

Question 38

What is the anterior cerebral artery (ACA)?

Answer 38

The anterior cerebral artery (ACA) refers to any of the arteries that supply blood to the medial side of each cerebral hemisphere and the corpus callosum. They are part of the cerebral arterial circle of Willis and branch from the internal carotid artery at the base of the brain.

Question 39

What is the middle cerebral artery (MCA)?

Answer 39

The middle cerebral artery (MCA) is the continuation of the internal carotid artery beyond the cerebral arterial circle (of Willis). It runs along the lateral (Sylvian) fissure between the frontal and temporal lobes. Branches of the middle cerebral artery supply blood to the frontal, orbital, parietal, and temporal lobes of the brain. Strokes involving the middle cerebral artery often result in sensory deficits and muscle weakness on the contralateral side of the body; when a middle cerebral artery stroke is in the dominant side of the brain, the patient can also have aphasia.