neuro important Flashcards
what does the arterial system of the brain originate from ?
internal carotid - anterior portion = 80%
vertebral arteries - posterior portion = 20%
where are berry aneurysms most likely to form?
the junctions/connections between branches in the circle of Willis
roughly what area of the brain does the anterior cerebral artery supply
anterior and middle portion of brain
roughly what area of the brain does the middle cerebral artery supply?
lateral sides of brain
roughly what area of the brain does the posterior cerebral artery supply ?
posterior portion of brain - occipital and some of temporal lobe
what would be the effect of a lesion of the ACA
loss of contralateral motor and sensory functions of lower limbs
what would be the effect of a lesion of the MCA
contralateral motor and sensory functions of upper limbs and face (+ Broca’s aphagia)
what would be the effect of a lesion of the PCA
Vision (leads to opposing side homonymous hemianopia with Macular sparing)
what structures are found in the cavernous sinus
(O TOM CAT) Oculomotor Trochlea Opthalmic Maxilliary Carotid (internal) Abducens (Trochlea)
what is cranial nerve 1 and what is its function
olfactory
smell
what is the pathway of CN I
olfactory epithelium -> olfactory bulb -> olfactory tract -> primary olfactory cortex (+ limbic system)
what type of fibre is CN I (olfactory)
sensory
what is CNII and what is it’s function
Optic
vision and sensory fibre for the pupillary light reflex and accommodation reflex
what type of fibre is CN II (Optic)
sensory
what is CN III and what is its function
Oculomotor
eye movement, pupillary light reflex and accommodation reflex
what type of fibre is CN III (oculomotor)
somatic motor
Oculomotor nucleus -> extraocular muscles except LR6SO4
autonomic motor/parasympathetic
Edinger-Westphal Nucleus -> ciliary ganglion -> ciliary muscles + sphincter pupillae
what is CN IV and what is its function
Trochlear
eye movement - superior oblique
what is the pathway of CN IV
Posterior Midbrain -> exits posteriorly -> loops round anteriorly -> SOF -> SO
what type of fibre is CN IV
motor
what is cranial nerve V and what are its branches
Trigeminal
opthalmic, maxillary, mandibular
describe the pathway of CN V
4 Nuclei along brainstem -> Trigeminal ganglion (Meckel’s cave) -> 3 branches
what kind of fibres make up CN V
Both
motor (muscles of mastication)
somatic sensory (pain, touch, temp, proprioception)
what are the functions of the V1-opthalmic branch of CNV
Somatic sensory: upper face, eyelids, lacrimal gland, and Ethmoid sinus
Autonomic sensory: sensory fibres for corneal reflex
what are the functions of the V2-maxillary branch of CNV
Somatic sensory: maxillary portion of face, upper teeth and lips, and nasopharynx