00:01
Now I just kind of alluded to all
these different types of receptors.
00:05
These are all called sensory
receptors and they’re all designed
to detect one sensory modality.
00:11
So in English, we’re
saying one type of sense.
00:13
And you know, you’ve all heard that
we have so many different senses,
five senses, ten senses.
00:18
The reality is, there’s
lots of senses.
00:21
There are some that kind of bubble
to the top that are quite common.
00:23
So we’ll highlight
some of those.
00:25
One is a mechanoreceptor.
00:27
So an example would be
the auditory hair cells.
00:29
We have little hair
cells at our inner ear.
00:33
The term mechano refers to
the fact that mechanical
stimulation or movement of these
cells will activate them.
00:40
So if you want to look at the chapter
about the ear and auditory function,
we’ll align this little
bit more detail.
00:46
But for now,
these little hair cells are in your
ear and this fluid-filled canal,
the sound gets carried in.
00:53
It causes a wave of movement which
moves the auditory hair cells
and that movement actually
initiates an electrical signal.
01:00
And that electrical signal
then goes on and gets
processed up by our brain which
is how we actually hear.
01:05
So chemoreception
is another one.
01:08
And two examples here are the
olfactory receptors which detect
chemicals in air, airborne
chemicals and allow us to smell.
01:17
We have the taste receptors
and this detect chemicals on your
tongue over the mucus membrane.
01:22
This nociception refers to pain.
01:25
There’s thermoreceptor which
respond to temperature
and that’s found in the
dermal layer of your skin.
01:30
Photoreceptors which are found
in the rod and cone of your eye.
01:33
We have a whole lecture
on the eyes as well.
01:35
So you can see, there’s a lot.
01:37
There are a lot of senses and there are
a lot of very specialized receptors.
01:41
Its only job is to detect
that sensory stimulation.
01:44
And another really kind of cool point
is mostly that I have showcased here,
it’s not just detecting the presence
or absence of that receptor.
01:54
So think about right now,
you close your eyes.
01:58
So go ahead and close your eyes
and you’re listening to the
soft, soothing voices of Tarry.
02:03
And if I ask you, can you tell me
whether or not the voice that you’re
listening to is male or female?
You better say male.
02:12
This is a male voice.
02:14
And am I in front of you
or am I behind you?
Am I speaking in English or am I speaking
in Hebrew? Am I speaking in Hindi?
And you’re able to figure all
of this out very quickly.
02:24
Can you tell whether I’m speaking
really fast or am I talking very slow?
How are you able to detect
all of this information
and do it without actively
thinking about it?
Okay.
02:35
So that’s you.
02:36
I’m asking you to kind
of appreciate that.
02:38
So open your eyes now and you get
to look at my pretty face again.
02:40
What you’re detecting here, all
the various features of sound.
02:44
So these receptors are
actually designed to not only
just detect the presence
or absence of a stimulus,
but various features of this sensory
information, which I find extremely cool.
02:56
So whether it’s eyes and all the different
aspects of vision, whether it’s sound,
if you think in our --
we have a whole lobe of our brain that is
allocated just dealing with vision, right?
The occipital lobe.
03:09
That’s all that it
does essentially.
03:11
And so that kind of helps you
appreciate the complexity
of some of the sensory
information that’s coming in.
03:17
So,
in summation, I want us
to appreciate all the
types of information that
we’re able to process,
how is it that we process it
converting all of those types of
sensory information into electrical
information and get sent up
to the central nervous system
where it’s processed and allows us
to interact with our environment.