1. How do organisms receive and respond to information from their environment?
Yesterday and today you worked with your partners on stations that tested your memory, emotion, attention, and language skills
What did they have to do with the brain?
Have students discuss their experiences very briefly. 
Inform students that this was the first lesson of a unit on the brain. Ask the class, “What does today’s lesson have to do with the brain?”
The goal is to guide them to recognize that each station represents a function controlled by the brain. Explain that by engaging in these activities, they were exploring ways that their brain works.
Direct student attention to the data table. Point out the variation in the results at each station. Ask students what do they think this means?
Some students may say that this means that some of them are “stupid” or “smarter.” Guide them away from value judgments. Instead, emphasize that there are individual differences in the ways brains respond to tasks. Students should realize that these differences make each of us who we are. 

2. Unit 5 B: Signals in Your Body
Add the new notes to your table of contents, and then turn to the next clean page and set up your title and date

3. Add sensory receptors to your index
Sensory receptors are specialized cells to detect specific stimuli
Interoceptors – detect stimuli inside the body
Include receptors for blood pressure, blood volume, and blood pH
Directly involved in homeostasis
Exteroceptors – detect stimuli outside the body
Include receptors for taste, smell, vision, hearing, and equilibrium
Add sensory receptors to your index

4. Types of Sensory Receptors
Chemical receptors – respond to chemicals
Taste, smell, blood pH
Photo receptors – respond to light energy
Vision (light)
Mechanical receptors – stimulated by mechanical forces
Hearing, gravity, motion, body position

5. Thermoreceptors – stimulated by changes in temperature
Located in the hypothalamus (region of brain) and skin
Nociceptors (Pain receptors) – free nerve endings that are stimulated by chemicals released by damaged tissue
Alert us to possible danger

6. Right Now
Copy down your homework
Take out your homework

7. How Sensation Occurs There are three steps to interpreting sensation:
Detection occurs when environmental changes stimulate sensory receptors
Sensation occurs when nerve impulses arrive at the cerebral cortex of the brain
Perception occurs when the brain interprets the meaning of stimuli
The cerebral cortex plays a key role in memory, attention, perception, awareness, thought, language, and consciousness

8. We are aware of a reflex action when sensory information reaches the brain
The brain integrates this information with other information received from other sensory receptors

10. Sense of Taste
Taste buds contain chemoreceptors and are located primarily in the tongue
Different receptors exist for salty, sour, bitter, sweet tastes and umami (savory)

11. How does the Brain Receive Taste Information?
Detection – food makes contact with your taste buds
Sensation – three different nerves in your tongue send signals to your brain
Perception – your brain interprets these signals and tells you what you are tasting

13. Sense of Smell
80-90% of what we perceive as taste is actually due to smell
Olfactory cells
Chemoreceptors are located high in the nasal cavity

14. How does the Brain Receive Odor Information?
Detection – during respiration scent molecules enter your nose
Sensation – nerve fibers in your nose send signals to your brain via the olfactory tract
Perception – your brain determines what you are smelling or an odor’s “signature”

16. Sense of Vision Vision requires the work of the eyes and the brain
It is believed that at least 1/3 of the cerebral cortex takes part in processing vision

17. How does the Brain Receive Sight Information?
Detection – light enters the eye, it is focused on photoreceptors in the retina
Sensation – signal is sent from optic nerve to the visual cortex
Perception – your visual cortex deciphers the image

19. Sense of Hearing
The ear has two sensory functions- hearing and balance (equilibrium)
Sensory receptors for both of these are located in the inner ear
Each consists of hair cells with stereocilia (long microvilli) that are sensitive to mechanical stimulation (mechanoreceptors)

20. How does the Brain Receives Sound Information?
Detection – sound waves enter the auditory canal and your ear drum vibrates
Sensation – the vibrations send signals to your auditory cortex
Perception – your brain interprets the sound

22. Sense of Touch
You probably think of the sense of touch as relating to your skin, after all, you have about 5 million sensory nerve receptors in your skin
When the touch, pain or heat sensors in your skin are stimulated, they send electrical pulses to your neurons, special cells that relay electrochemical impulses 

23. How does the Brain Receive Feeling Information?
Detection – contact is made with sensory receptors
Sensation – sensory receptors send signals to spinal cord
Perception – brain receives and translates signal from spinal cord to determine feeling (touch, pain, heat, etc.)