HARC- Neurosensory 2

Question 1

How many PAIRs of spinal nerves are there?

Answer 1

31

Question 2

Each spinal nerve is connected to the spinal cord by a ______ root and a ______ root

Answer 2

dorsal

ventral

Question 3

Cross section of spinal cord

Answer 3

Question 4

How might the axons be described in terms of incoming (= afferent) or outgoing (= efferent) and sensory or motor?

Answer 4

Sensory = incoming/afferent;

Motor = outgoing/efferent

Question 5

Name all the tracts the arrow is pointing to?

Answer 5

Question 6

Why is there 8 cervical nerves but only 7 cervical vertrbrae?

Answer 6

Nerves run almost horizontally, and that one nerve emerges above (C1 nerve) and one below (C2 nerve) the C1 vertebra.

Question 7

What does commissural mean? How do commissural fibres differ from association fibres?

Answer 7

Commissural describes fibres crossing midline directly (as opposed to projection fibres which decussate obliquely); Association fibres connect different areas within a hemisphere.

Question 8

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Question 9

identify whether each is composed primarily of grey or white matter

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Question 10

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Question 11

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Question 12

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Question 13

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Question 14

What landmark structures delineate each lobe?

Answer 14

Central sulcus divides frontal and parietal lobes; lateral fissure separates frontal and temporal lobes; parieto-occipital sulcus divides parietal and occipital lobes on medial surface

Question 15

Which lobes occupy which fossae?

Answer 15

Frontal lobes > anterior cranial fossa;

Temporal lobes > middle cranial fossa;

Cerebellum > posterior cranial fossa

Question 16

– the larger the relevant body part, the _____ neurons innervate it.

Answer 16

more

Question 17

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Question 18

What principle functions are associated with these gyri?

Answer 18

Primary motor cortex and primary somatosensory cortex, respectively (as depicted)

Question 19

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Question 22

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Question 24

: Where do you think the most likely points for blockage of the ventricular system are?

Answer 24

IVFs, cerebral aqueduct, foramina of Magendie and Lushka

Question 25

What has the arachnoid mater to do with spiders? Between which of the layers does cerebrospinal fluid (CSF) accumulate and act as a shock absorber?

Answer 25

Trabeculae resemble spiders’ webs. Arachnoid and pia mater (= sub-arachnoid space, SAS)

Question 26

In a lumbar puncture, where would be a reasonable place to decant CSF in the adult? In the child?

Answer 26

L3/4 (distant from spinal cord, and allows maximal separation of lumbar spinous processes with flexed trunk)

Question 27

What causes the cervical and lumbar enlargements of the spinal cord?

Answer 27

Cervical and lumbosacral plexuses for the arms and legs

Question 28

How does the vertebrobasilar system connect with the carotid arterial system of the brain? Why is this structure important?

Answer 28

Circle of willis to provide a backup arterial supply

Question 29

Eye and Visual Pathway:

Answer 29

Question 30

What type of substance fills each of the chambers? What are the borders of each of the chambers?

Answer 30

Aqueous humour fills both chambers while vitreous humour is found behind the lens; Anterior chamber is between the cornea and the iris and the posterior chamber is between the iris and the lens.

Question 31

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Question 32

Lens What is the lens attached to? What is the ciliary body? What reflex occurs here?

Answer 32

Ciliary process of the ciliary body by suspensory ligament; Contains smooth muscle fibres for changing the lens and is involved in the accommodation reflex

Question 33

Iris What are 2 different types of muscle fibres in the iris? What are their functions?

Answer 33

Radial and annular smooth muscle fibres ; Radial is dilator pupillae and annular is sphincter pupillae

Question 34

Optic Nerve What 2 types of visual field are travelling through this nerve?

Answer 34

Temporal (lateral) and nasal (medial)

Question 35

Optic chiasma What happens to the sensory information here?

Answer 35

The nasal (medial pathways cross over while the temporal (lateral) pathways stay ipsilateral

Question 36

Optic tract Where does the optic tract start and end?

Answer 36

After the chiasma until the lateral geniculate bodies in the thalamus

Question 37

Optic radiation Where is it and what is its function?

Answer 37

Information is passed through to the visual cortex

Question 38

Visual cortex What lobe of the brain would you find the visual cortex?

Answer 38

Occipital lobe, calcarine sulcu

Question 39

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Question 41

Recti muscles: Superior, inferior, lateral and medial rectus What is the common origin of the recti muscles and where do they insert? What movement do they impart on the eyeball?

Answer 41

Common tendinous ring and anterior to the equator of the eye; refer to table in Gray’s textbook and VITAL HARC Neuro 1 Video

Question 42

Oblique muscles: Superior and inferior obliques What is the origin and insertion of superior oblique? What is the origin and insertion of inferior oblique? What are the movements of the eye by the oblique muscles?

Answer 42

Just above the common tendinous ring, along the medial wall of the orbit, turns through the trochlea to insert underneath the tendon of superior rectus; Anteromedial wall of the orbit, underneath the eyeball to insert above lateral rectus; refer to textbook table

Question 43

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Question 45

Pinna : What function does the pinna serve?

Answer 45

Direct sound waves into the external acoustic meatus

Question 46

External acoustic meatus : What is the function of the external acoustic meatus? Is it composed of cartilage, bone or both

Answer 46

Both 1/3rd cartilage and 2/3rd bone

Question 47

Medial surface of tympanic membrane : What is attached to the medial surface?

Answer 47

Handle of the malleus

Question 48

Malleus and the incus : Which is found most lateral?

Answer 48

Malleus because it is attached the medial side of the tympanic membrane

Question 49

Stapes and the oval window Why is the stapes attached to the oval window?

Answer 49

Transmit the vibrations of the ossicular chain into the fluid-filled inner ear

Question 50

Pharyngotympanic tube : Where does the pharyngotympanic tube exit? What is its function?

Answer 50

Exits into the nasopharynx and it equalises pressure in the air-filled middle ear (when your ears pop)

Question 51

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Question 52

Petrous temporal bone What parts of the inner ear are found here?

Answer 52

Both – the hearing and vestibular parts as well as the bony and membranous labyrinths.

Question 53

Bony labyrinth (cochlea, vestibule and semicircular canals) What type of fluid is found in these spaces?

Answer 53

Perilymph

Question 54

Membranous labyrinth (cochlea and canal ducts) What type of fluid is found in these ducts? What are the scala vestibuli and the scala tympani? Where is the Organ of Corti?

Answer 54

Endolymph ; Scala vestibuli is the perilymph filled part found above the cochlear duct and the scala tympani is the perilymph filled area found below the cochlear duct

Question 55

Vestibulocochlear nerve Name the functional component associated with this nerve?

Answer 55

Special Somatic Afferent

Question 56

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Question 59

Somatosensory and Motor Pathways

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Question 60

Somatosensory and Motor Pathways

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Question 61

Somatosensory and Motor Pathways

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Question 62

Anterior and lateral spinothalamic tracts What type of sensation do these tracts carry? And, where do these fibres decussat

Answer 62

Anterior carries crude touch and pressure while lateral carries pain and temperature; At point of entry in the spinal cord after synapsing with the 2nd order neuron

Question 63

Posterior (dorsal) columns: What type of sensation does it carry? And, where do these fibres decussate? And, when do these fibres become part of the medial lemniscus?

Answer 63

Fine touch, pressure, vibration, proprioception from skin and joints; pyramids; after decussating and cuneate and gracilis have combined in the brainstem

Question 64

Spinocerebellar tract : What type of sensation do these tracts carry? And, where do these fibres decussate?

Answer 64

Proprioceptive information to the cerebellum; It doesn’t it stays ipsilateral

Question 65

corticospinal descending tract Where does it originate? Where does it decussate? Where does the nerve impulse end? What is the corticobulbar tract?

Answer 65

Upper motor neurons from the primary motor cortex; Pyramids of the midbrain; Muscle fibres; Head and neck portion of the corticospinal tract that synapse with cranial motor nuclei in the brainstem

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Question 68

the internal capsule: What shape is it? Between which two nuclei is it sandwiched? And, what runs through it, particularly the posterior limb?

Answer 68

Boomerang with an anterior limb, a genu and a posterior limb; Thalamus medially and the lentiform nucleus laterally, specifically the globus pallidus of the lentiform nucleus; The corticospinal tract

Question 69

What is this?

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Question 70

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