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3ESO Touch - Contenido educativo

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Subido el 16 de febrero de 2021 por Marta G.

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How are you seeing this video? How are you hearing? Why are you touching the pencil that 00:00:00
you have in your hand? Because of a very special organs that you have in our body. 00:00:06
We are going to study the five most important organs. Point number two, sense organs. 00:00:14
the first sense organ that we are going to study is our skin the sense of touch 2.1 touch 00:00:21
what are the different parts of our touch how can we feel heat cold pressure harm how do we 00:00:48
feel all this. Let's cut our skin and see inside. As you can see it's not an easy 00:01:02
drawing to do but I know you will do the best. Let's see, the skin is made up of 00:01:09
three different layers. On the upper part we have the epithermis, this upper part 00:01:18
here. This upper part is special because it's compound of different layers but 00:01:24
but the only one who is dividing is this one here, I made an arrow in this line here, 00:01:30
is where all the divisions of the different cells are done. 00:01:38
The cells divide, but as you can see, the blood capillaries do not reach the epidermis. 00:01:43
So how do they get the nutrients? How do they get the oxygen? 00:01:49
They cannot. So after a few days of living, they die. 00:01:53
them but luckily to us even though they die they perform a very special function which is to 00:01:57
protect us these layers will be coming up and up and up higher up until they make the outer part 00:02:05
of our skin so basically our skin is made up of that cells that's why if we cut our cell but it's 00:02:14
a superficial cut we don't get hurt or we don't get blood out of it why because in the epithermis 00:02:23
there is no blood capillaries the middle part is the dermis and it's the place where all the 00:02:30
receptors that we have in our skin are we have different types of receptors but remember receptors 00:02:36
are neurons yes the same neurons that we have seen in unit number seven these neurons with their 00:02:45
axon their cell body the dendrites are here in specific places which are receptors and they are 00:02:54
going to transmit the information from the skin up to our brain to the cortex to the cerebral cortex 00:03:04
in order to perform a response to that touch as you can see there are different structures 00:03:13
which goes from the epidermis to the dermis like for example like for example the hairs 00:03:21
that we have all around our body we have certain areas where we have more hair than other like 00:03:28
our head but usually in all our body we are full of hair which have the function of protecting us 00:03:35
as you can see the hair comes from the epidermis and it's inserted in the dermis by the 00:03:45
hair follicle there are also some detectors of pain there some receptors for the pain that's why 00:03:52
if we try to push our hair and get it out we are hurt there are also some sebaceous gland 00:04:02
that i represent here here like this which secrete some fats that are going to lubricate and make 00:04:11
our skin more flexible it's very they are very very important for our skin 00:04:23
they can also cause troubles for example in puberty your hormones are really high or really 00:04:29
low so with these hormones disorder what happens is that the sebaceous glands start secreting a lot 00:04:36
of fat that's why you can have green on your face or have acne that's a problem with the skin at 00:04:46
your age. Also, there are some sebaceous glands which have special function for mammals. Remember 00:04:54
that we are mammals, so we feed our babies with milk, with the women's milk. Our mammary glands 00:05:01
are sebaceous glands that are modified to secrete milk instead of secreting fat. 00:05:09
But let's go with the receptors that we have in our skin. We do not have only one type of receptor, 00:05:17
depending on the sensation that we have we have one receptor or another let's 00:05:23
start with the thermoreceptors those who are related with temperature it's not 00:05:28
the same to feel cold or to feel hot we have different receptors the Krause 00:05:34
corpuscles these corpuscles are related to cold temperatures but instead 00:05:39
related to warm temperatures we have the Ruffini endings. In these endings we have 00:05:47
the sensation of heat or warm temperatures. If we talk about pressure, we 00:05:57
feel pressure on our skin, we can have a superficial touch, in this case the 00:06:04
The masonry corpuscles are activated, but if it's a deeper pressure, we have the patini's corpuscle working here, 00:06:12
depending on the superficial or internal. 00:06:21
And what happens with the sensation of pain? 00:06:25
Imagine that we cut or we burn, we have different sensations. 00:06:27
First, if we cut, we have the pressure and then we have the pain. 00:06:33
Then, the pain, they are responsible, the nerve endings. 00:06:36
We have nerve endings here all around our skin and when we get hurt they transmit the information to the brain and the rest of our body. 00:06:40
And the last layer of them is the hypothermia, is the lower one of them. 00:06:51
In this layer we have a connective tissue, we have an adipose tissue. 00:06:59
and if you remember from the unit number to the tissues you will remember that the adipose tissue 00:07:05
is the one related with fats so we have cells which inside have a lot of fats 00:07:13
and its duty is to protect the skin and to make contact with the organs that we have under our 00:07:20
skin do we have the same sensation of touching every part of our body well as you can see in 00:07:28
the picture that does not happen why because in our hand we need to get a really really concrete 00:07:35
and specific touch to grab things or to carry things to us on our lips we need to have special 00:07:44
receptors to get food inside our mouth so the areas where there is a special need of touch we 00:07:53
have more receptors of them so there is different for each area of our body what about the color of 00:08:00
our skin why there are different races and the different races have different colors well it's 00:08:07
not the same to live in the equator than living on the poles people who live near the equator 00:08:14
they have more insulation from the sun direct insulation so their skin needs to be protected 00:08:21
so they have more of these cells called melanocytes melanocytes are going to dark the skin 00:08:28
and protect the people who live in those locations whereas people that live on the northern areas 00:08:37
they have very few hours of sunlight during the day especially during winter even in summer the 00:08:45
the sun is really low. What they need is to get as much light as possible. That's why they need 00:08:52
to synthesize more vitamin D with the skin. There is a problem for people who move from 00:09:00
northern areas to the equator because they need to put a lot of sun tan so they don't get burned 00:09:08
and also from people who live near the equator and go to northern countries because they need 00:09:14
supplements of vitamin d because if not their body doesn't work correctly and you can see skin 00:09:22
has a lot of interesting facts a lot of different things to learn about a lot of different receptors 00:09:30
so i hope you enjoyed this class tomorrow we'll talk about the senses of smell and taste 00:09:37
Idioma/s:
en
Autor/es:
Marta García Pérez
Subido por:
Marta G.
Licencia:
Reconocimiento - No comercial - Sin obra derivada
Visualizaciones:
114
Fecha:
16 de febrero de 2021 - 19:02
Visibilidad:
Clave
Centro:
IES FORTUNY
Duración:
10′
Relación de aspecto:
1.78:1
Resolución:
1920x1080 píxeles
Tamaño:
893.47 MBytes

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