Download Option A.3 Pt 1 - Peoria Public Schools

Perception of stimuli
Option A.3
Receptors detect changes in the
environment.
• List and describe the types of specialized
receptors in humans.
a. Mechanoreceptors- respond to
movement.
b. Chemoreceptors- respond to chemicals.
c. Thermoreceptors- heat.
d. Photoreceptors- light.
Labelling a diagram of the structure of
the human eye
Rods and cones are photoreceptors
located in the retina.
• Describe the retina.
a. A thin layer of light sensitive tissue at
the back of the eye.
• Describe what rods and cones do for the eye.
a. Rods and cones work together to detect
the image focused on the retina.
Rods and cones differ in their sensitivities to light intensities and
wavelength.
• Compare and contrast rods and cones.
a. They are both photoreceptors in the
retina. Rods work well in dim light and give us
black and white vision. Cones work well in
bright light and give us color vision.
• List the three types of cones.
a. Red, blue, green
Red-green color blindness as a variant
of normal trichromatic vision
• What is red-green color blindness caused by?
a. The absence or a defect in a gene for
photoreceptors for red or green cone cells.
• Why is it more common in males?
a. It is more common in males because it
is a recessive allele carried on the X
chromosome. Males have only one X so will
show the trait if recessive.
Annotation of a diagram of the retina
Bipolar cells send the impulses from
rods and cones to ganglion cells
• Describe the job of bipolar cells.
a. Bipolar cells synapse with rod and cone
cells to carry a message to the ganglion cells.
Ganglion cells send messages to the
brain via the optic nerve
• Describe the structure of ganglion cells.
a. Ganglion cells have cell bodies in the
retina and dendrites that synapse with bipolar
cells. They also have long axons that pass
impulses to the brain.
The information from the right field of vision from both eyes is
sent to the left part of the visual cortex and vice versa
• Name the spot where axons from the left and
right sides cross over.
a. Optic Chiasma