Name: Stephanie Frost Section: Bio 201

Lab Report: Reflex and Special Senses

Please fill out this report and submit it to the dropbox. Do not hand in your own form. It will not be graded and you will receive a zero for the lab.

You must get all parts correct to get credit for the question * Please note that although you do not hand in items in observations, it is very important to do these as you may see some of these items on future/associated lab quizzes or be asked about some of these concepts on unit assignments.*

Activity 1: Stretch Reflexes

QUESTIONS:

A. Which muscles
And transduction of light into nervous impulses is the chief function of the retina, without doubt.1The retina is a multi-layered sensory tissue that lines the back of the eye. It contains millions of photoreceptors that capture light rays and convert them into electrical impulses. These impulses travel along the optic nerve to the brain where they are turned into images.2 1. http://www.vetmed.vt.edu/education/curriculum/vm8054/eye/retina.htm 2. http://www.stlukeseye.com/anatomy/retina.html
What is the function of the choroid layer? Vascular layer that provides nutrients to the retina, pigment scattered and reflected light to minimize glare within the eye. http://wwwmgs.bionet.nsc.ru/mgs/gnw/trrd/thesaurus/Se/eye.html
B. What is the difference between rods and cones? Am I likely to use my cones more or my rods more when trying to see in the dark? The rods and cones are the actual sites of transduction of light energy into neuronal signals. They are, in essence, exceptionally specialized bipolar neurons, which have developed some structural features to carry out this task. The rod is the "model" transducer. The mechanism by which light energy is converted to neuronal signals is exactly the same in both rods and cones; the difference between the two types of receptor are in the visual pigments involved. Rods respond to very low levels of light at all wavelengths of the visible spectrum by