Sensory Systems and Vision

These flashcards cover vocabulary and key concepts from the lecture on Sensory Systems, focusing on visual anatomy, optical problems, and neural processing pathways.

Law of Specific Nerve Energies

The principle that whatever excites a particular nerve establishes a special kind of energy unique to that nerve.

Thalamus

The relay station for stimuli such as light, sound, touch, or chemicals, with the exception of olfaction.

Vision

A result of the interaction of light with the structures of the visual system, where photons induce depolarization or hyperpolarizations in visual receptors.

Rods

Receptors responsible for response in dim light and peripheral vision; there are approximately $120 \text{ million}$ rods in the eye.

Cones

Receptors responsible for response in bright light and detailed vision; there are approximately $6 \text{ million}$ cones in the eye.

Pupil

The first entrance of light into the eye.

Retina

The structure containing receptors sensitive to light where transduction occurs.

Fovea

The area responsible for sharp central vision (foveal vision) necessary for activities like reading and driving; it contains only cones.

Hyperopia

Also called farsightedness, a condition where the eyeball is too short and near objects appear blurry.

Myopia

A condition where light focuses in front of the retina because the eyeball is too long or the cornea has too much curvature.

Blind Spot

The field where the optic nerve leaves the eye, containing no receptors.

Neural Convergence

The pooling of signals where, on average, about $120$ rods compared to $6$ cones send signals to one ganglion cell.

Visual Acuity

Detail vision, which is superior in cones compared to rods due to having less convergence.

Optic Chiasm

The location where optic neurons contralateralize due to the charechteristics of the species.

Lateral Geniculate Nucleus (LGN)

A part of the Thalamus to which optic nerves project before reaching the Striate Cortex (Visual Cortex).

Superior Colliculi

Brain nuclei involved in eye movements and reflexes.

Hypothalamus (Visual System function)

An area where optic nerves project to regulate the Circadien rhythm.

Magnocellular pathway (M pathway)

The visual pathway starting from retinal ganglion cells that responds to motion and depth.

Parvocellular pathway (P pathway)

The visual pathway starting from retinal ganglion cells that responds to visual details, colour, and shape.

Koniocellular pathway (K pathway)

A visual pathway from the retinal ganglion cells that responds specifically to color.

V1

The primary visual cortex.

V2

The first primary association area and hippocampal connections.

V5

A specific area of the visual cortex dedicated to motion.

Dorsal pathway

The Occipito-Parietal Pathway, also known as the Where/How pathway, involving the parietal lobe.

Ventral pathway

The Occipito-Temporal Pathway, also known as the What pathway, involving the temporal lobe.