To begin to understand what smell is we must talk about the organ responsible for this sense: the nose.
The nose is a protuberance located between the eyes and the mouth. It is part of our respiratory system, allowing us to breathe in and out. In addition to breathing, the nose allows different odors to enter from our surroundings.
THE PROCESS OF SMELL
1. Molecules in the air reach the nostrils by breathing.
2. Specialized receptor cells called olfactory receptor neurons detect the odor.
3. The olfactory receptors transmit the information to the olfactory nerve, which is located at the back of the nose.
4. The olfactory nerve sends the information to the brain and the brain interprets the information as smell.
INTERESTING FACTS
People can detect at least one trillion distinct smells.
Olfactory cells are renewed every 30 to 60 days.
Women have a better sense of smell than men.
Dogs have nearly 44 times more olfactory cells than humans .
Each human being has their own distinct odor.
Our sense of smell peaks during our late teens, when we are around 18 or 19 years old.
Do you want to learn more about the sense of smell? Visit this website!
NEURONSare the cells of the nervous system. They have different parts with different functions:
-Cell body: it controls the neuron and creates nerve impulses.
-Dendrites: specialized projections that bring information to the cell the body.
-Axon: specialized projection that takes away information from the cell body.
NEURONS create electrical signals called nerve impulses to transmit messages from one cell to the next. The information goes from dendrites to axon in a neuron. There is a space between neurons called synapse and the nerve impulse needs chemicals called neurotransmitters to pass this gap between one neuron's axon and reach the next neuron's dendrites, where it becomes an electrical signal again.
(Pay attention: this is not explained correctly in your textbook!)
3D Models of Neurons
NEURON SONG
(from http://ihaveago.com)
Verse 1 -
A neuron is a cell of scientific fascination,
They receive, process and transmit information,
They allow us to think, solve problems and grow,
To learn the things we thought we could never know.
Chorus -
My abilities can be developed
With dedication and effort
When I find the right strategy
The one that works best for me.
Verse 2 -
Our brains have billions of neurons in a busy constellation,
Connected by branches in a network formation,
They fire in patterns, electrically,
Creating every feeling, thought and memory.
(Chorus)
Verse 3 -
Whenever I struggle, make mistakes and corrections,
I’m creating and strengthening my neuron connections.
Stimulating my brain and making it grow,
Making room for all the new amazing things I know.