Neuro Olfactory & Visual Flashcards
What type of cells make up the olfactory system?
SSA (special sensory afferent)… they are found in the surface epithelium
How often are the afferent neurons of the olfactory system replaced?
every month
What do we call the centrally directed process of the bipolar primary afferent neuron?
the olfactory nerve
What does the olfactory nerve pass through?
the cribfiform plate
What are mitral cells and where do they project?
Mitral cells are neuronsthat are part of theolfactory system. They are located in the olfactory bulb in the mammaliancentral nervous system. They receive information from the axons of olfactory receptor neurons, forming synapses in neuropilscalled glomeruli. Axons of the mitral cells transfer information to a number of areas in the brain
They project to the cerebral cortex
Olfactory dysfunction may be an early sign of what?
Alzheimer’s disease
Where is the olfactory cortex located?
The piriform cortex which includes:
1) uncus
2) periamygdaloid cortex
3) anterior entorhinal cortex
Trace the path of the olfactory signals
uncus —> peramygdaloid cortex —> anterior entorhinal cortex —> posteior orbitofrontal cortex via mediodorsal nucleus of thalamus
Olfactory tract neurons arise from the _____ and terminate in the _____
olfactory bulb….. piriform cortex
Where is olfaction thought to be appreciated?
the posterior orbitofrontal cortex
What is the area of the eye that has the best vision?
macula lutea & fovea centralis
What do you call the blind spot on the retina?
optic disc (the area where optic nerve fibers exit the eye)
_____ is the visual neuroepithelium
The retina
What are the 3 layers of neurons in the retina?
rods/cones
bipolar cells
ganglion cells… which then exit the eye and make up the optic nerve
Ganglion _____ cells serving the macula ae small and are the origin of the _______ “what” visual system
midget… parvocelllar
Ganglion ______ cells serving the periphreal retina are large and are the origin of the _____ visual system
parasol…. magnocellular
What is the optic nerve covered with?
dura mater, arachnoid mater, and the accompanying subarachnoid space, and the pia mater
Increased CSF pressure around the optic nerve affects what?
the optic disk
What part of the brain deals with circadian rhythm?
hypothalamus suprachiasmatic nucleus
Where in the brain does the pupillary light reflex originate?
pretectum. The afferent component is the optic nerve and the efferent component is the oculomotor nerve. There is a direct reflex and a consensual reflex
How is the retina connected to the amygdala?
it is DIRECTLY connected and is relayed through the superior colliculus. It is responsible for transmission of emotionally significant image
What is the lateral geniculate body responsible for?
visual information. It contains geniculocalcarine projections
The occipital lobe is responsible for visual information. The primary (striate) visual cortex is area ____ and the secondary and tertiary cortices (extrastriate) are areas ____ and ____
17
18 & 19
Someone who has Blindsight is a cortically blind individual but can respond to stimuli anyway. What is the hypothesized pathway for this?
retina —-> lateral geniculate body —-> extrastriate cortex (areas 18 & 19)
What is anton syndrome?
it is the loss of the primary visual cortex and vision but is accompanied by a denial of loss
What is visual agnosia?
agnosia means “not knowing” and involves a loss of the secondary and/or tertiary visual cortices, especially on the dominant side of the brain
What is Charles Bonnet Syndrome?
it involves visual hallucinations and is associated with age and reduced vision (cataracts, glaucoma, & macular degeneration) as well as post-surgery recovery. The visual hallucinations involve images of people and/or animals and are amusing or disturbing but NOT EMOTIONAL
What is prosopagnosia?
it is the loss of ability to name faces and is associated with a lesion of the fusiform face area
What is the fusiform face area?
it is the inferior aspect of the occipitotemporal cortex and predominates on the non-dominant side.
