Week 7: Sensory
many kinds of eye-glasses used for special purposes. People who fish like to
wear polarizing sunglasses. People who shoot guns competitively, typically wear
amber colored glasses. Conduct some research to determine why each prefers a
particular kind of eye-wear.
This laboratory exercise
gives you an opportunity to study how we sense changes in our surroundings.
Your ability to sense changes in your surroundings involves (1) the specific
ability of sense organs to respond to stimuli (detection), (2) the
transportation of information from the sense organ to the brain by way of the
nervous system (transmission), and (3) the decoding and interpretation of the
information by the brain (perception). In order for us to sense something, all three
of these links must be functioning properly. For example, a deaf person might
be unable to detect sound because (1) there is something wrong with the ear
itself, (2) the nerves that carry information from the ear to the brain are
damaged, or (3) the portion of the brain that interprets information about
sound is not functioning properly. While this laboratory activity focuses on
the function of sense organs, it is important to keep in mind that the
peripheral and central nervous systems are also important in determining your
sensory ability. All sense organs contain specialized cells that are altered in
some way by changes in their environment (stimuli). The sensory cells
depolarize and since they are connected to nerve cells, they cause the nerve cells
to which they are attached to depolarize as well, and information is sent to
the brain for interpretation by way of nerve pathways.
In this lab exercise you
1. Make a map of
the location of different kinds of taste buds on your tongue.
2. Determine several
characteristics of the sense of “touch.”
different kinds of temperature sensors in the skin.
4. Study several
aspects of visual acuity.
5. Study several
aspects of the sense of hearing.
Taste involves several different kinds of sensory
cells located on the tongue and pharynx. Each kind of sensory cell responds to
specific kinds of chemicals. So there is not just one sense of taste; there are
several. We recognize at least five different kinds of taste senses: sweet,
sour, salty, bitter, and umami (meaty).
the Sense of Taste on the Tongue
1. Work with a lab
a cotton swab and dip it into one of the solutions. The solutions are labeled
sweet, sour, salt, bitter, and umami (meaty).
your lab partner touch the swab to the tongue at the following five locations: a.
the tip, b. right side, c. left side, d. center, and e.
Place an X on
the following drawings of the tongue to indicate where you detected each