Visual fields Flashcards
Names of the lobes of the brain
Frontal
Occipital
Temporal
Parietal
What nerve fibres cross and where do they cross?
Nasal at the optic chiasm
What leaves the optic chiasm and what does each one contain?
Optic tracks- right and left
right: right temporal nerve and left nasal nerves
Left: left temporal nerve and right nasal nerves
Where do the optic tracks synapse?
LGN: lateral geniculate nucleus
What happens after the LGN
optic radiation travels from the LGN to the primary visual cortex in the occipital lobe. There are 2 routes of optic radiation: Meyers loop and one that goes direct.
Describe the different routes of optic radiation from the LGN
Meyers loop: information from the upper visual field travels to the lower retina. a ventricle obstructs the field of optic radiation so the optic radiation had to go through the temporal lobe forming Meyers loop.
The info from the lower visual fields travels to the upper retina and travels directly through the parietal lobe.
Where does optic radiation end up?
Primary visual cortex in the occipital lobe
If the same side of the circle is affected in both eyes where must the problem in the visual pathway be?
After the chiasm
If the problem is in the lower visual field, where if the problem?
Parietal lobe
If the problem is in the upper visual field where is the problem?
Temporal lobe
If a pt has total blindness In one eye where is the problem?
Optic nerve
IF the patient has bitemporal hemianopia where is the problem? what is the most common cause of bitemporal hemianopia?
Optic Chiasm
pituitary tumour
If a patient has contralateral homonymous hemianopia where is the problem?
Optic tract
what is bells palsy? How does it present?
Paralysis of CN VII- facial nerve.
Presents with a dry eye as the eye wont close fully on blink reflex but can close on conscious blinking.
Where are tears formed?
Lacrimal glands watery part, Meibomian gland for oily part (prevents tears evaporating) and mucous from conjunctiva
