0:09
This lab discussion is about the senses and we're going to touch on the general and special senses. When we think about information that our body gathers from our senses we generally think of our special senses of taste and vision and smell and when we think of those things we generally are t...
0:09
This lab discussion is about the senses and we're going to touch on the general and special
senses. When we think about information that our body gathers from our senses we generally
think of our special senses of taste and vision and smell and when we think of those things we
generally are thinking of eating a good meal, seeing a pretty day outside or hearing music that
we enjoy, but the sensory information that we bring into our body goes far beyond any kind of
pleasurable sensation that we do receive. The information that we gather from our senses is
essential for our intellectual functioning, for personality development. It can also be essential
for our life sustaining properties for example
1:02
one of our senses, one of our abilities, is to send pain. If we are missing the ability to sense
pressure or pain then we can't react to that stimulus and remove ourselves from a harmful
stimulus. Another example is there have been studies from prisoners that haven been in
isolation and the effects of that solitary confinement to their intellectual functioning. It has been
shown that people who have been in that solitary confinement with sensory deprivation have
been known to hallucinate visually and have tactile hallucination. And also demonstrate an
intellectual decline. So the information that we gather from our senses is vital to our life. How
do we detect changes in our environment through our body? The first line of a reception are
things called a sensory receptor
2:02
Sensory receptors are structures specialized to detect the senses and also to convert one
form of energy into another. So for example the sensory receptors will gather in information
from the environment
2:18
so if it is in light or a sound it will convert that energy into a nerve signal and then that nerve
signal will be sent to the brain for processing The sense organs that we have in our body are
specialized structures composed of
2:32
nervous tissue, and other types of tissue that work to enhance the response that we gather
from the environment and from the sensory receptors. What types of receptors do we have in
our body? We have
2:45
different types of receptors that will respond to different types of stimuli. We have
thermoreceptors that will respond to heat or cold. Photoreceptors, these are found and our
eyes, they respond to light. Chemoreceptors will be something that respond to a chemical, so
an oder or a taste would be something that would be classified as the receptor that will gather
that information. Nocioeceptors are receptors in the body that respond to tissue injury, so
these are our pain receptors.
Those are examples of the different types receptors that we have in our body that respond to
different types of stimuli. In the body there are 2 general or broad classes of senses. We have
our general senses and the receptor for these senses are widely distributed through the body,
in our muscles, in our joints, in organs, inside of our body. These senses respond to stimuleye
like general touch,
4:01
pain, Temperature, and things like that that are more of a widely distributed type of sensation.
The second type of sense that we have is our special senses. The special senses are limited to
,the head and they are innervated by our cranial nerves. The sense organs that go along with
the special senses are much more complex- the sense organs are very complex tissue
structures that gather in this information from the environment.
4:30
Examples of our special senses are the ones that were probably the most familiar with: Vision,
hearing, taste, equilibrium, and smell. The 2 special senses that we're going to discuss today
are vision and hearing.
First we're going to discuss the auditory sensation and our equilibrium. The auditory system is
responsible for our sense of hearing and also for our sense of equilibrium. It will help us to
detect sound and it will help us to maintain our bodies sense of balance.
5:02
Our cranial nerve number 8, the vestibular cochlear nerve, is the nerve that is responsible for
the system. The vestibule branch will innervate the division of this system that controls
equilibrium and the cochlear branch will control the division that is involved in hearing. The ears
are divided into 3 sections. We have an outer or external earl, a middle ear, and an inner ear. All
3 of these sections are responsible for hearing.
5:31
Only the inner ear is responsible for our sense of equilibrium. More specifically about the
hearing component the first 2 parts, the outer and the middle ear are more concerned with
conducting this down waves in to the inner ear where they are processed as sound. If we look
at our poster and look at the external ear, again the external ear is a funnel for collecting sound.
It is going to direct the sound waves
6:01
through the canal and end at the eardrum. we’re going to look at the parts that make up this
external ear.
It begins with something called the pinna or the auricle. This is basically our ear lobe, when
we're looking at the outside we're looking at this this funnel like structure, is going to help
collect and direct down waves. It is shaped and supported by very a thick skin and elastic
cartilage. There is no cartilage however in the ear lobe at the bottom. So there is no bone
present in this outer ear in this auricle. The opening in the auricle is called the external
acoustic meatus. That is the opening that the sound waves enter before entering further into
that ear into the
7:01
Outer ear which is called the auditory canal. The sound waves enter into the external acoustic
meatus and they travel in through the auditory canal. The outer ear ends at something called
the tympanic membrane. So the sound waves gather in/through the auricle, directed through
the auditory canal, and they end at the tympanic membrane, also known as the eardrum. If we
look more specifically at this auditory canal, we're looking at a canal that is formed out of bone.
It’s the temporal bone of this skull. and it is lined with a very thick skin and it also has some
cartilage present. In this canal there are guard hairs. Guard hairs are present to help protect
the ear from any debris. So it will
8:01
help to keep out debris out of the ear and from entering into the further components that could
cause damage to the ear structures. There are glands in this little auditory canal called
sebaceous glands. Sebaceous glands secrete oil. Once this oil is secreted it will sometimes
, mix with our dead skin in the canal and it will form something called cerumen or commonly
known as ear wax. That ear wax or cerumen will coat those guard hairs and help them to do
their job even more effectively because any foreign debris trying to enter into the canal will kind
of stick on to those guard hairs because the cerumen or the ear wax has the stickiness to it
that will help to protect the ear from those foreign objects. So if we finish up our discussion on
that outer ear
9:02
We start at the auricle, we go into the auditory canal and we end at the tympanic
membrane. So the tympanic membrane or the eardrum marks the end of the outer ear and
the beginning of the middle ear.
If we look a little more specifically at the tympanic membrane the surface that faces the
auditory canal is a concave surface, so the outer most surface of that ear drum is concave or
shapes or turns in. The inner surface or the internal surface would be more convex, so it's
going to turn or curve out, on the inside surface. Again this separates the outer ear from the
middle ear, It is found at the end of the auditory canal and when those sound waves enter into
the auditory canal it will cause a vibration or a transmission of the sound waves from the
tympanic membrane.
10:25
The next division of the ear is the middle ear. The middle ear is about 2-3 mm wide. It’s a very
small portion of the ear And of course it is found between the outer and the inner ears So we're
looking right around this area And if you look at the poster
it’s where the the boney section is a little bit darkened for us to know that we're looking at the
middle ear section. So the middle ear begins tympanic membrane and it's going to include the
following structures first for looking at the Eustachian tube or the auditory tube (dark pink
tube under white area and whee middle ear is written in picture above). So we want to be
careful not to confuse the auditory tube with the auditory canal in the outer ear. So refer to it as
the Eustachian tube. The Eustachian tube connects the middle ear to the nasopharynx,
which we learned about in the digestive system that nasopharynx is part of the throat region,
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Welch1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.48. You're not tied to anything after your purchase.
