CHAPTER 6: THE EYE Flashcards
What is sensation?
Involves cells in the nervous system that are specialized to detect stimuli from the environment.
What is perception?
Conscious experience and interpretation of information from the senses.
What allows the eye to detect light stimuli?
photoreceptors in the eye
What wavelength of electromagnetic radiation is visible to us?
between 380 nm and 760 nm.
What wavelength of electromagnetic radiation is visible to us?
between 380 nm and 760 nm.
What is hue?
dominant wavelength
What is brightness?
intensity
What is saturation?
purity
At what speed does light travel?
300 000km per second
Slower oscillations= ….. wavelengths?
longer
What happens if the radiation contains all visible wavelength ?
no sensation of hue, appears white.
What is a sensory receptor?
- specialized neuron
- detects a particular category of physical events
What is sensory transduction?
process by which sensory stimuli are transduced into slow, graded receptor potentials-
What is a receptor potential?
-Slow- graded electrical potential produced by a receptor cell in response to a physical stimuli
What part of the eye must the image be focused on?
- the retina
- focus is aided by bones and muscles surrounding the eye.
What are the eyes suspended in ?
the orbits
How is the eye help in place and moved?
-by extraocular muscles attached to the sclera
What are the conjunctiva?
mucous membranes that line the eyelid and fold back to attach to the eye.
What is responsible for regulating the amount of light entering the eye?
pupils
What is responsible for accomodation?
- the lens
- control by ciliary muscles
What are the three cellular layers of the retina?
From BACK to FRONT:
- photoreceptive (rods and cones)
- bipolar cells
- ganglion cells
Are there more rods or cones in the retina?
more rods than cones
What are rods responsible for?
-low intensity light vision
What are cones responsible for?
acuity, colour vision, daytime vision
