Question | Answer |
What is anosmia? | no smell |
What is hyposmia? | decreased function |
What is cacosmia? | hallucinatinoof unpleasant smells (aka: uncinate fit before seizure) |
How often is the mucosa replaced on olfactory epithelium? | every 10 minutes |
Where are olfactory receptors? | dendrites of neurons that extend into the mucosa |
How are olfactory receptors activated? | depolaraize the first order neurons in the olfactory pathway |
What kind of neurons are the first order neurons? | bipolar neurons |
Where is the first synapse? | olfactory bulb |
What happens in the olfactory bulb? | first order neurons synapse on the second order neutrons |
What are the second order neurons in the olfactory tract called? | mitral cells |
How many first order neurons compared to second order neuron? | a lot more first order neurons. 4-5 first order neurons synapse on second order neurons |
What does the olfactory tract split into? | lateral and medial olfactory stria |
What does the lateral olfactory project to? | pyriform and entorhinal regions of the cerebral cortex and the amygdale |
Where does the medial olfactory stria project to? | projects to the contra-lateral olfactory bulb via the anterior commissure |
Where does the olfactory tract go to? | telencephalon |
Is the thalamus involved with olfaction? | no |
What are the layers of the eye from outermost to innermost? | sclera, choroid, retina |
What is the innermost layer of the eye? | Retina |
What is the outmost layer of the retina? | 1 |
What is the innermost layer of the retina? | 10 |
How many layers of the retina are there? | 10 |
What is layer one of the retina? | pigment epithelium filled with melanin to absorb light |
What do cones do? | absorb color; light |
What do rods do? | low light vision |
What does layer 2 of the retina do? | contains the receptor portion of rods and cones |
What does layer 6 of the retina do? | contains the cell bodies of horizontal, bipolar and amacrine neurons |
What does layer 8 of the retina do? | contains the cell bodies of ganglion cells |
What does layer 9 do? | contains the axons of the ganglion cells; they become the optic nerve |
What do the ganglion neurons do? | project axons that become the optic nerve |
What do bipolar neurons in the eye do? | link between the receptor neurons and the ganglion neurons |
What are the amacrine and horizontal neurons? | interneurons in the retina that make synapses on other neurons…involved in processing |
What are the two area of specialization in the retina? | optic disk and fovea centralis |
What is the fovea centralis? | an area of the retina conaining only cones. The upper retinal layers are shifted to the side at the fovea so that light may hit the photoreceptors here without any distortion. |
What is at the optic disk? | a blind spot…no optic cells at all |
What is the macula lutea? | area with no vasculature where the fovea is |
What is the central visual pathway? | produces vision |
What are the two pupillary pathways? | one ot the iris (pupil constriction and one to ciliary body (lens accommodation) |
What is the visual association pathway? | superior colliculus |
What is the reticular pathway? | produces alterness |
What is the hypothalamic pathway? | circadian rhythm |
Where do all visual pathways start? | retinal photoreceptors |
What are the first order neurons in the eye? | bipolar neurons |
What are the second order neurons in the eye? | ganglion neurons |
Where is the optic chiasm? | just anterior to the infundibulum |
What is the optic chiasm? | a decussation of optic fibers |
What continues past the optic chiasm? | optic tracts |
What information does each optic tract carry? | information from the contralateral visualfriends. |
Where does the optic tract run to? | lateral geniculate body, pretectal area, superior colliculus, reticular formation and suprachiasmatic nucleus |
What is the central visual pathway? | conveys visual information to the cerebral cortex to produce the visual perception |
Where do 80% of the fibers of the optic tract synapse? | lateral geniculate body |
What layers of the lateral geniculate body receive axons from the ipsilateral eye? | layers 2,3 and 5 |
Where do axons of the controlateral eye go in the lateral geniculate body? | 1,4 and 6 |
Where are 3rd order neurons in the optic pathway? | neurons in the lateral geniculate body |
Where do third order neurons project to? | primary visual cortex |
What divides the occipital lobe horizontally? | calcarine fissure |
Where is the primary visual corex? | calcarine fissure |
What is the geniculcalcarine tract? | third order neurons going from the lateral geniculate body to the calcarine fissure |
What is meyer’s loop? | geniculocalcarine tract |
What is agnosia? | inability to recognize objects |
What is prospagnosia? | inability to recognize faces (right occipitoparetal corex) |
What does V1 of the occipital lobe do? | visual awareness |
What does V2 of the occipital lobe do? | segregation of the viusal info |
What does V3 of the occipital lobe do? | form |
What does v4 of the occipital lobe do? | color |
What does V5 of the occipital lobe do? | movement |