Neuroanatomy - Auditory and Visual Pathways Flashcards
where are the organs of hearing and balance located?
in the inner ear
what nerve facilitates hearing?
CN VIII (cochlear)
where do the nerve fibres for the cochlear nerve starts and where do they travel to?
the primary auditory cortex in the superior temporal gyrus
pass down to the cochlear nucleus
what nuclei are important in sound localisation?
olivary nucleus
nucleus of the lateral leminiscus
where do fibres carrying information about low frequency sounds go in the auditory cortex?
the anterolateral part
where do fibres carrying information about high frequency sounds go in the auditory cortex?
posteromedial part
what is aphasia?
the inability to use language
what two areas can be damaged resulting in aphasia?
broca’s area
wernicke’s area
how does broca’s aphasia present?
difficulty producing language, using a few words and only saying the most important words
dont usually struggle to understand language
what are other names for broca’s aphasia?
motor aphasia
expressive aphasia
how does wernicke’s aphasia present?
difficulty comprehending language
what are other names for wernicke’s aphasia?
sensory aphasia
receptive aphasia
what nerve mediates balance?
CN VIII (vestibular nerve)
how are objects projected onto the retina and why?
reversed and upside down
because of the shape of the lens
where is information from the lower visual field projected to in the brain?
the gyrus superior to the calcarine sulcus
where is information from the upper visual field projected to in the brain?
the gyrus inferior to the calcarine sulcus
where is information from the macula projected to in the brain?
the posterior pole of the visual cortex
what is another name for the optic radiation?
the geniculocalcarine tract
where do fibres of the geniculocalcarine tract originate?
initially form part of the internal capsule
describe the direct and consensual reflexes of the pupillary light reflex
shine light into the right eye
right pupil constricts = direct light reflex
left pupil constricts = consensual light reflex
what is hemianopia?
blindness for half of the field of vision in one or both eyes
what is the term form when vision is lost in the same visual field in both eyes?
homonymous
the opposite is heteronymous
name three different types of fibres in the white matter of the cerebral hemispheres
association fibres
commissural fibres
projection fibres
what do association fibres do?
connect cortical sites lying in the same hemisphere
what do commissural fibres do?
connect one hemisphere to the other
usually connecting areas with similar functions
what do projection fibres do?
connect hemispheres to deeper structures such as the thalamus, corpus striatum, brain stem and spinal cord
