Neuroanatomy of auditory and visual pathways Flashcards
What two nerve nuclei are important in sound localization and as relays for stapedial and tensor tympani reflexes?
Superior olivary nucleus
Nucleus of lateral lemniscus
At what part of the auditory cortex do nerves fibres carrying information regarding low frequency sound end up?
Anterolateral part
At what part of the auditory cortex do nerves fibres carrying information regarding high frequency sound end up?
Posteromedial
If a patient is having difficulty in producing language, often using few words and only saying the most important words in a sentence but they do not seem to have trouble understanding language where is the damaged area?
Broca’s area
If the patient has difficulty understanding language and expresses meaningless words or words out of order where is the damaged area?
Wernicke’s area
Which of the areas (broca’s or wernicke’s) is reponsible for the motor part of speech?
Broca’s
Which of the areas (brocas or wernicke’s) is responsible for the sensory/receptive part of speech?
Wernicke’s
What part of the midbrain receives information from the optic tract and also send out information for eye movements?
Superior colliculus
What is the lateral geniculate nucleus?
A relay center in the thalamus for the visual pathway. It receives a major sensory input from the retina. The main central connection for the optic nerve to the occipital lobe.
What sulcus is the primary visual cortex in?
Calcarine sulcus
Which part of the visual pathway is responsible for producing movements in response to visual stimuli for example tracking moving objects?
Visual cortex
What part of the visual pathway is responsible for movements of command (ie movements that are independent of moving visual stimuli
The frontal eye fields
Which movements (tracking or command) tend to be jumpy?
Movements of command
Which movements (tracking or command) tend to be smooth?
Tracking movements
What is the end point of the optic tract?
Lateral geniculate body
At the lateral geniculate body, neurones synapse with neurones that go on to form the….?
Optic radiation
Where does the optic radiation end?
In the visual cortex of the occipital lobe
Is the left visual field of each eye represented by the right or left occipital cortex?
Right
What part of the occipital lobe does the macular vision go to?
Occipital poles
What part of the occipital cortex does the upper visual field project to?
Inferior to the calcarine sulcus (lingual gyrus)
What part of the occipital cortex does the lower visual field project to?
Superior to the calcarine sulcus ( cuneus)
About 1% of optic tract fibres peel off before reachign the lateral geniculate body; where do they go?
Pretectal nucleus of the midbrain
What happens to the optic tract fibres that have gone into the pretectal nucleus of the midbrain?
The go to the edinger westphal nucleus (bilateral projection) that then sends ot motor fibres to the iris causing pupillary constriction
What is the reason for the consensual light reflex?
The pretectal fibres project bilaterally to the edinger westphal nucleus
With regard to the white matter of the cerebral hemisphere; what are association fibres?
They connect cortical sites lying in the same hemisphere
With regard to the white matter of the cerebral hemisphere; what are commissural fibres?
They connect one hemisphere with the other, usually connecting areas of similar function
With regard to the white matter of the cerebral hemisphere; what are projection fibres?
They connect hemispheres to deeper structures including the thalamus, corpus striatum, brain stem and spinal cord
