1. The Sensory System

2. I. Function
Receptors sense changes environments.

5. II. Types of Receptors
Chemoreceptors- changes in chemical concentrations
Pain receptors- Tissue damage
Thermoreceptors- changes in temperature
Mechanoreceptors- pressure and movement
Photoreceptors- light energy

6. III. Sensation
Sensory receptor receives a stimulus and sends it to the brain along a sensory neurons.
The brain (interneurons) interprets the signal as a sensation

7. IV. There are 5 Senses
Touching
Seeing
Hearing
Tasting
Smelling

8. Lets do a lab- Pain
With your eyes closed, your partner should place the two ends of the paper clip far apart on your INDEX FINGER and slowly move them closer together. Record the distance, in millimeters, at which they feel like ONE point.
Repeat for back of Hand
Repeat for Forearm
Repeat for Calf

9. How about another lab - Temperature
Place your left index finger in the ice water and your right index finger in the hot water. Record which finger adapts more quickly to the temperature.
Now remove both fingers from the hot and cold water and place them in the room temperature water. Record what you felt in each finger.

10. 1. Touch and Pressure
Uses mechanoreceptors, thermoreceptors, and pain receptors.

11. a. Temperature b. Pain Warm and Cold Receptors Adapt quickly
above 113 and below pain
b. Pain
Receptors in skin and internal tissue
Responds to damaged tissue
Adapts poorly

12. Pain Control In the presence of severe pain neuropeptides are released
Neuropeptides block pain signal

13. 2. Vision
Involves
photoreceptors

14. Light passes through pupil and is focused on retina.
Image is upside down and reversed, brain interprets image

15. Draw Figure 35-13 Label the following Structures
Optic Nerve
Sclera
Retina
Iris
Pupil
Lens
Cornea
Rods
Cones

16. Iris- colored portion of eye, controls amount of light in the eye
Aqueous humor- fills space between cornea and iris, provides nutrients to cornea and shape
Pupil- circular opening into eye
Sclera- white of the eye

17. Cornea- transparent connective tissue allows light in
Lens – focuses light on Retina
Retina- sheet of tissue that contains the visual receptor cells
Optic Nerve- attached to back of eye

18. A. Visual Receptors
1. Rods- colorless and dim light vision,
2. Cones- Color Receptors
Rhodopsin- light sensitive chemical in rods
Cones have one of three light sensitive pigments that detect different wavelengths of light.
-Green, Red, and Violet

19. involves chemoreceptors
3 and 4. Smell and Taste
involves chemoreceptors
Smell- Olfactory Receptor cells
Taste- Taste Bud
Both adapt quickly

20. 5. Hearing and Balance
The ear

21. Hearing Sound waves enter the ear Ear drum vibrates
Vibration travels down three bones of inner ear
Stimulate hairs in the cochlea

22. 7. Equilibirum Canals lined with hairs and filled with fluid
Maintains balance based on position of head when the body is still
Detect motion and maintains balance

23. The sense of sound

24. 3. Auditory ossicles amplify and transmit vibrations to the end of the stapes

25. 4. Movement of stapes at oval window transmits vibrations to perilymph in scala vestibuli

26. . Vibrations pass through vestibular membrane and enter endolymph of cochlear duct

28. 6. Different frequencies of vibration in endolymph stimulate different set of receptor cells
7. As a receptor cell depolarizes, its membrane become more permeable to calcium ions.

29. 8. Inward diffusion of calcium ions causes vessicles at the base of the receptor cells to release neurotransmitter

30. 9. Neurotransmitter stimulate end of nearby sensory nerves