Chapter 7 Neuroscience Exam - UC Merced

Sensation

detection of stimuli

Perception

interpretation of stimuli

Photons

elementary particle of light that is also a wave, and a particle

Wavelength (400-700 nm)

visible spectrum/colors

Cornea

anterior portion of the eye, like actually front most part, u put ur contact lens here, refracts or bends light

Lens

refracts light, convex on both sides, able to adjust its shape thru accommodation

Accommodation

lens adjusting shape, thru the cillary muscle

Pupil (Mydriasis / Miosis)

the hole, dilates - mydriasis, constricts - miosis

Retina

the posterior most part of the eye, where light is converges

Fovea

fewer cell bodies present, photons of light are not refracted, heavily leans towards cone receptors

Optic Disk

elipitical spot, absence of photoreceptors, unable to perceive light called the blind spot

Blind Spot

in the optic disk because of lack of photoreceptors

Rods

rod shaped, high synaptic convergence, for periherial vision, mostly concertarted outside the fovea, helps us see at night

Cones

high acuity vision, most densely packed at fovea, for color,

Phototransduction

process of dectecting photos of light and convert them into neurotransmitter release

Lateral Inhibition

the circuitry of the horizontal cells. In being activated, they block adjacent signaling pathways from also sending information forward. Because horizontal cells inhibit adjacent neurons at the same "level," we describe this phenomenon as lateral inhibition

Horizontal Cells

interneurons that do not directly participate in the pathway of signaling in visual perception.

Optic Nerve

cranial nerve ii, exits posterior end of the eyeball and travels posterirorly along the ventral surface of the brain goes into thalaumus and then the primary visual cortex,

Optic Chiasm

where the two optic nerves meet and cross, some nerves are contralateral and some are ipsilateral

LGN

lateral geniculate nucleus, first synapse of the optic nerve found in the thalamus, divided into 6 layers, named 1 thru 6, from ventral to dorasal (up to down)

Optic Radiations

series of axonal bundles, divided into two main bundles, upper and lower divisions, upper carries information from the lower visual field, and vice versa

Primary Visual Cortex (V1)

striate cortex, output of LGN which form synapses in V1, large white stripe that can be seen visually because its myleniated

Retinotopic Mapping

orgazinatioal pattern, where a section of retinal inputs map onto neurons of a specific section of V1

Dorsal vs. Ventral Stream

Dorsal

described as the 'where" pathway because these structures help us identify where things are in space around us, includes V2 and V5

Ventral

"what" pathway and help us identify objects we see, important for visual memory

Akinetopsia

motion blindness

Prosopagnosia

face blindness

Glaucoma

optic nerve destruction mainly from intraocular pressure

Saccades

rapid eye movements, small jerking movements driven by the actions of the extraocular muscles

Circadian Regulation (SCN)

superchiamastic nucleus, helps with the sleep-wake cycle