(135) Chapter 2 Flashcards
Absorption spectrum
What is the plot of the amount of light absorbed versus the wavelength of the light?
Action potential
This denotes the signal which lasts about 1 millisecond w/c happens from resting potential at (-70 mV) –> (+40 mV) –> negative again –> resting potential again.
Amacrine cells
Other than bipolar and ganglion cells, and receptors, what are the two types of neurons that connect neurons across the retina? (2)
Signals traveling between bipolar and ganglion cells use this.
Axial myopia
Eyeball is too long; images of faraway objects are not focused sharply.
Axon
_____ is filled with fluid that conducts electrical signals.
Bipolar cells
Where do signals generated in the receptors travel to first?
Blind spot
This is a spot where there are no receptors (receptors are missing).
Cell body
This is the key component of neuron. This contains mechanisms to keep the cell alive.
Cone spectral sensitivity curve
What do you call a curve that is produced when an observer looks directly at a test light so that it stimulates only the cones in the fovea?
(Neural) Convergence
This occurs when a number of neurons synapse onto a single neuron.
Dark adaptation
The process of increasing sensitivity to light in the dark
Dark adaptation Curve
A function which relates sensitivity to light to time in the dark, beginning when the lights are extinguished.
Dark-adapted sensitivity
“This threshold, the minimum amount
of energy necessary to just barely see the light, is converted to sensitivity; it is measured while the eyes are adapted to the light; 100,000 times greater than the light-adapted sensitivity mea- sured before dark adaptation began”
Dendrites
These parts of the neuron branch out from the cell body to receive electrical signals from other neurons
Depolarization
Process which shows the inside of the neuron becoming more positive; causes the charge to change in the direction that triggers an action potential; an excitatory response
T/F
detachment of retina to pigment epithelium can occur as a result of traumatic injuries of the eye or head, as when a baseball player is hit in the eye by a line drive.
Excitatory response
This occurs when the inside of the neuron becomes more positive; one of the two types of responses by the receptor sites.
Far point
_____ point is he distance at which light becomes focused on the retina.
Fovea
It only contains cones. When we look directly at an object, the object’s image falls on this one.
Ganglion cells
Where do signals generated in the receptors travel to after the bipolar cells?
Horizontal cells
Other than bipolar and ganglion cells, and receptors, what are the two types of neurons that connect neurons across the retina? (2)
Signals travel between receptors through here.
Hyperopia
This condition happens when the focus point for parallel rays of light is located behind the retina, usually because the eyeball is too short.
Ions
They are molecules that carry an electrical charge; present in the liquid solution of neurons.
Retinal changes shape from being bent to straight and detaches from the opsin.
What happens in isomeization?
Lateral geniculate nucleus
These signals (from receptors transported to neurons w/in retina) are transmitted out of the back of the eye in the optic nerve to a group of neurons
Lens
20% of the focusing power goes here.