In this lab, you will investigate the behavior of the human nervous system and make observations of the special senses.
Activity 1: Touch Receptors (worth 10 points total)
- List four sensations detected by the tactile receptors in the skin(1)
(2)
(3)
(4) - Get a volunteer to touch each of these locations on your body using the same pressure. Close your eyes and rank how sensitive each area is from 1 (low sensitivity) to 5 (high sensitivity). Put your rankings in the chart.Touch Receptors
Location
Rank the concentration of receptors (Low:1-High:5)FingertipHeel of handForearmElbowBack of neckAnswer this question:- What can you conclude about the density of touch receptors in your skin?
Activity 2: Vision (worth 15 points total)
- Label the parts of the eye in the picture. The choices are optic nerve, cornea, iris, pupil, lens, and retina.(1)
(2)
(3)
(4)
(5)
(6) - Test the age of your eyes.
- Hold a pencil or ballpoint pen vertically at arm’s length.
- Close your left eye and focus on the tip.
- Quickly bring the pencil closer to your eye until it is out of focus.
- Have your partner measure the distance between your eye and the pencil.
- Repeat for both eyes.
- Try it with and without glasses (if you wear glasses).
Cm91013185083Age102030405060Answer these questions:- What was the “age” of your eyes?
Right without glasses ______________ with glasses __________________
Left without glasses ________________ with glasses __________________ - How does this compare to your actual age?
- Use your notes from this lesson to describe how the eye processes what is sees.
- Using what you know about eyesight and image processing, why can age affect the function of the eyes?
Activity 3: Hearing and Balance (worth 15 points total)
- Label the parts of the ear in the picture. The choices are ear canal, oval window, cochlea, pinna, tympanic membrane, ear ossicles, cochlear nerve, semicircular canals, and Eustachian tube.(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9) - Test your sense of balance.
- Stand upright with your partner nearby in case you fall.
- Have your partner record the length and quality of your attempts
- Bend your right leg and hold your foot in your right hand.
- Balance like this as long as you can (minimum 30 seconds).
- Try the same pose, but close both of your eyes.
- Again, have your partner nearby recording your attempts.
- Balance for as long as possible.
- Try the same pose, but close your eyes and tilt your head back slowly.
- Again, have your partner nearby recording your attempts.
- Balance for as long as possible.
Balance
Stance | Time (min.) | Stability |
Standing on one foot | high—moderate—low | |
One foot, eyes closed | high—moderate—low | |
One foot, eyes closed, head back | high—moderate—low |
Answer these questions:
- Which stance made it the hardest to balance? Why do you think that is?
- How much of an impact does your inner ear have on your sense of balance?
Activity 4: Taste and Smell (worth 15 points total)
- Your tongue has a variety of receptors capable of tasting different types of flavors. Pick four liquids to test for taste and a volunteer. Use the picture provided to “map out” your taste buds.
- Obtain a few sterile swabs.
- Pipet a small amount of each solution into separate test tubes or cups but don’t let your volunteer know what liquids you are using ahead of time.
- Using one solution at a time, dip a swab and run it along your volunteer’s tongue.
- Record where your volunteer is able to taste each solution and what it tastes like.
- Now repeat the process again, this time have your volunteer plug his or her nose during the tasting.
- Label where on your tongue you tasted each of the following: SALTY BITTER SWEET SOURTaste
Types of LiquidTaste TypeLocation on the tongueTaste Type with nose pluggedLocation on the tongue with nose plugged - Use your lesson notes to explain the results for the taste sensations in each of the regions of your tongue?
- Can you explain why it may be more difficult to map taste with your nose plugged?