Hearing
•What is the stimulus for hearing?
•Sound
•What is sound?
•Vibrations of different wavelengths
•Different wavelengths produce different pitches
•What media can sound waves travel through?
•Gas, liquid, and solid
How do we hear?
1.Sound waves are gathered by the outer ear
2.Sound waves strike the eardrum, causing it to vibrate
3.Vibrations pass from the eardrum to the hammer, anvil,and stirrup in the middle ear
4.Vibrations are send to the cochlea, which contains fluidand hair cells
5.The hair cells bend in response to vibrations, which sendsan electrical message to the auditory nerve
6.The auditory nerve carries this message to the temporallobe
7.Messages can be carried further to other areas of the brainin order to compare sounds and make sense out of whatwas heard
Why do we sound different to ourselves?
When you talk, the sound waves travelthrough your jawbone and through yourmouth as well as through the air in yourear
When you listen to yourself on tap, thesound waves only travel through the air inyour ear
What are some affects of listening to loudnoise?
•Long exposure to sound above 80 decibels permanently damages haircells in the ear, causing hearing loss
•Excessive noise causes high blood pressure, quicker heartbeats,learning difficulties, and disturbed sleep patterns
Why is sound important?
•Give three examples in which being able to hear sound is veryimportant. Identify the stimulus and response in each example.
Smelling
•What is the stimulus for smell?
•Chemicals in the air
•What are the seven basic odor types?
•Floral
•Mint
•Camphor
•Ethereal
•Must
•Pungent
•Putrid
How do we smell?
1.Chemicals in the air go through the nasal cavity and up to the top of the nose
2.The top of the nose is covered with mucus, which dissolves the chemicals
3.The top of the nose has multiple types of smell receptors
4.Each receptor has a special shape that can only fit certain chemical molecules
5.When a chemical molecule fits the receptor, the receptor sends a message to a neuron
6.The neuron sends the message to the olfactory bulb (under the frontal lobe) and thento the temporal lobe
7.Messages can be carried further to other areas of the brain in order to compare smellsand make sense out of what was smelt
How does a cold affect your sense ofsmell?
•Each sinus has lining that produces mucus that drains to the nose andthroat; when the lining gets infected or inflamed, mucus builds up becauseit is unable to drain, causing pain and pressure
•When the lining is inflamed and infected, the chemicals do not fit thereceptors, so you cannot smell as easily
Why is smell important?
•Give three examples in which being able to smell is very important.Identify the stimulus and response in each example.
How are smell and taste related?
•About 70% of what we taste comes from our sense of smell
•Taste buds on our tongue allow us to detect bitter, salty, sweet, andsour flavors
•Odor molecules from food give us most of our taste sensation
How do we taste?
1.Chemicals dissolve in saliva on our tongue, whichhas taste buds covering it
2.Taste buds contain receptors that respond toeither salty, sweet, sour, or bitter
3.When chemical touches receptor, receptor sendselectric message to neuron
4.Neuron sends message to the temporal lobe
5.Messages can be carried further to other areas ofthe brain in order to compare tastes and makesense out of what was tasted
