Neuroanatomy

Question 1

Draw and label an axon

Indicate the direction of travel of the action potential

Answer 1

Question 2

Draw and label the brain:

Forebrain

Brainstem

Cerebellum

Answer 2

Question 3

What are the main divisions of the spinal cord?

Answer 3

C1-C5

C6-T2 - Brachial plexus

T3-L3

L4-S3 - Lumbosacral plexus

Question 4

Draw and label the spinal cord

Answer 4

Peripheral white matter - nervous afferent and efferent tracts

Central grey matter - interneurones and motor neurones

Question 5

How many pairs of spinal nerves are there?

Answer 5

36

Question 6

Describe the two aspects of the autonomic nervous system.

Answer 6

Parasympathetic - craniosacral (vagus nerve and sacral plexus)

Sympathetic - thoracolumbar (sympathetic chain)

Question 7

Bladder filling

Answer 7

Detrusor muscle relaxes

Sphincter tone increases

Sympathetic

Question 8

Bladder emptying

Answer 8

Detrusor muscle contracts - parasympathetic

Sphincter muscle relaxes - sympathetic to internal, somtic to external

Question 9

Horners syndrome

Answer 9

Leisons to sympathetic chain (remember supply to the eye, 3 neurones, travels via entire cervical section of spine) - results in eye pathology

• Miosis - interoccular muscles
• Ptosis
• Extruded 3rd eyelid - orbitalis muscle

Corrected with phenylephine

Question 10

CTZ

Answer 10

Central trigger zone (outside of the BBB so exposed to drugs!)

Question 11

BBB

Answer 11

Blood brain barrier - prevents toxins and drugs getting into CNS

Question 12

Outline the circulation pathway of the CSF

Answer 12

• Produced in the choroid plexus
• To lateral ventricles
• Interventricular foramen
• 3rd ventricle
• Mesencephalic aqueduct
• 4th ventricle
• Lateral apatures
• Subarachnoid space

Question 13

What is the function of CSF?

Answer 13

• Shock absorption in CNS
• Suspends parenchyma
• Modulates pressure changes in the CNS
• Regulates ICP
• Transport of metabolites, neurohormones and neurotransmitters

Question 14

Olfactory nerve

Answer 14

Smell

Synapses onto olfactory lobe

Question 15

Optic

Answer 15

Visual pathway

Recieves info from rod and cone cells

Question 16

Occulomotor

Answer 16

Extraoccular muscles:

Ipsilateral - Dorsal, ventral and medial rectus and ventral extraocular, levator palpebrae superioris

Parasympathetic:

Pupillary constriction

Question 17

Trochlear

Answer 17

Contralateral dorsal oblique (crosses over in midbrain)

Question 18

Abducens

Answer 18

Ipsilateral lateral rectus and retractor bulbi

Question 19

Trigeminal

Answer 19

Sensory to the face

Motor to the muscle of mastication - temporalis, masseter, pterygoids, cranial digastricus

Question 20

What are the three branches of the trigeminal nerve?

Answer 20

Opthalmic - cornea, medial canthus, nasal muscle

Maxillary - lateral canthus of the eye, cheek, muzzle, palate, nasopharynx

Mandibular - oral cavity and mandibular skin

Question 21

Facial

Answer 21

Motor to muscles of facial expression

Sensory - rostral 2/3 of tongue and palate

Parasympathetic - lacrimal, mandubular and subligual gland

Question 22

Vestibulocochlear

Answer 22

Hearing and vestibular function

Inner ear receptors to medulla

Question 23

Glossopharyngeal

Answer 23

Motor to pharynx and palate

Sensory to caudal to 1/3 of the tongue

Parasympathetic - parotid and zygomatic glands

Question 24

Vagus

Answer 24

Motor to larynx, pharynx and oesophagus

Sensory to larynx, pharynx, thoracic and abdominal viscera

Parasympathetic to all thoracic and abdominal viscera

Question 25

Accessory

Answer 25

Motor to trapezius, sternocephalicus and brachiocephalicus

Question 26

Hypoglossal

Answer 26

Motor to tongue muscles Sensory to tongue bulb

Question 27

Reflexes

Answer 27

Sensory neurone synapsing directly/ indirectly onto lower motor neurone Monosynaptic - patella Polysynaptic (brain comms) - withdraw

Question 28

How does a lesion in the cranial spinal cord lead to incontinence?

Answer 28

Upper motor neuron injury - sympathetic supply Reduced emptying due to reduced detrusor stimulation - dilated and difficult to express bladder

Question 29

What is the function of an upper motor neuron? What are the different motor tracts and their function?

Answer 29

Within the CNS - modulation (often inhibitory) to lower motor neurons Pyramidal (corticospinal) - fine, skilled movement Extrapyramidal (brainstem - spine) - postural, rythmic moements

Question 30

What is the function of the vestibular system?

Answer 30

Balance Orientation relative to gravity Eye, neck, trunk and limb position relative to head

Question 31

Otoliths within a cupula

Answer 31

Macula

Question 32

Hair cells surrounded by a cupula

Answer 32

crista ampullaris

Question 33

What is the afferent and efferent supply to the PLR?

Answer 33

Optic to PLR to Occulomotor (iris circular muscle)

Question 34

What is the afferent and efferent supply to the menace response?

Answer 34

Optic to menace to facial

Question 35

What is the function of the ARA system?

Answer 35

Arousal, awaking the brain, preparing the brain to recieve sensory information