Vision

1. __________ photoreceptors are used for bright light conditionsand for seeing _______. ________ photoreceptors are used form dimlight conditions. There are ______types of cones. Blue conesrespond best to light of _____; Red cones respond best to light of________; and green cones respond best to light of _________. Rodsrespond best to light of _______.
2. The part of the photoreceptor that responds to light is the__________ which is made of ________ and ________.
3. In the dark, cGMP opens _________ on the photoreceptors whichallows ______ to enter. This is called the __________ whichdepolarizes the ________ which releases ________ to inhibit bipolarcells. As a result, bipolar cells can’t activate __________. As aresult, no _________ is generated in the optic nerve.
4. In the light, photons of light strike to photopigments toconvert ________ to _______. This change activates _________ whichactivates __________ which converts cGMP to ________. A decrease incGMP decreases the _________ current. As a result, bipolar cellsare no longer inhibited by _______. Bipolar cells then stimulate_________ which generate action potentials in the ________.
5. The scotopic system uses many _________ to activate fewer________ which activate fewer _________. This is an example of__________. This system uses _________ to respond to low intensitylight
6. The photopic system uses __________ to activate __________ toactivate __________. Due to the lack of __________, this system isnot suitable for __________ but it is ideal for _________.
7. Visual pathway
   1. Bipolar cells synapse with _______ in the retina which, inturn, synapse in the ________; third order neurons then terminatein the _________ where vision is perceived.
8. Vision abnormalities
   1. _________ is also called nearsightedness; in this conditionimage comes into focus _________
   2. _________ is also called farsightedness; in this condition,image comes into focus ________
   3. _________ is condition that prevents the image from coming intofocus
   4. _________ is normal vision

Hearing

1. The pitch of a sound is based on its ________. The loudness ofsound is based on its ________. Loudness is measure using a_________ scale. 20 db is ________ times louder than the hearingthreshold.