シャドーイング練習: The Integumentary System - 動画で英語スピーキングを学ぶ
練習モードを選ぶ
各モードは全画面の練習ルームで開きます。
100 文
文が短すぎたり長すぎる場合は、Editをタップして調整してください。
1
It’s Professor Dave, let’s look at the integumentary system.
デイヴ教授です。今回は外皮系を見ていきましょう。
2
With some basics covered regarding two of the types of tissue in the human body, we are ready to start looking at some of the different systems found in the body, and we are going to start with the outermost system, which is called the integumentary system.
3
This is made up of the skin that covers and protects all your other body parts, as well as its derivatives, like certain glands, as well as hair and nails.
4
Let’s look at the structure and function of these components now.
5
The skin is a remarkable organ, acting as the first line of defense from the elements that surround us.
6
It keeps bacteria out, and water and heat in, so let’s check out the structure of skin.
7
Our skin is made of two regions, a thin outer layer, which is the epidermis, and a thicker inner layer, called the dermis.
8
The dermis, which is a tough layer of fibrous connective tissue, is vascularized, getting its nutrients from the bloodstream.
9
The epidermis, which is made of epithelial tissue, is avascular, so it gets nutrients by diffusion through the tissue fluid from the dermis.
10
In addition, below the dermis is the subcutaneous layer, also called the hypodermis.
11
This is made predominately of adipose tissue, and it anchors the skin to other structures below.
12
Now let’s zoom in on the epidermis, the thin outer layer of the skin.
13
This is made of keratinized stratified squamous epithelium, made of four different cell types in five layers.
14
The deepest layer, the one attached to the dermis, is called the stratum basale, meaning basal layer.
15
This is made of a single row of cells, most of which are called keratinocytes.
16
These are rapidly dividing all the time, pushing new cells up into the layers above, to help regenerate dead skin, and producing lots of keratin as they do so.
17
This is necessary because millions of dead keratinocytes rub off your skin every day, due to friction, and even more from your hands and feet, so these constantly dividing cells in the stratum basale ensure that a new epidermis forms every few weeks, so that we always have our skin intact.
18
This layer also contains melanocytes, which produce melanin, and tactile cells, which act as the sensory receptor for touch.
19
Above this is the stratum spinosum, meaning prickly layer.
20
This section is several layers of cells thick, and is full of cells with a weblike system of intermediate filaments attached to desmosomes.
21
They look kind of spiky, so they are sometimes called prickly cells.
22
Here we can also find dendritic cells, which ingest foreign substances and activate the immune system, which we will talk about later.
23
Next is the stratum granulosum, or granular layer.
24
This is four to six cell layers thick, and in this section, keratinization begins as cells continue to move their way upwards from the basal layer.
25
This is when the cells get far enough from the dermal capillaries below to receive sufficient nutrients, so the cells fill up with keratin as they die, and they flatten while the organelles disintegrate.
26
This makes the cell tougher and scalier, which allows for the outer layers to better protect the body.
27
Above this is the stratum lucidum, or the clear layer.
28
This is two or three cell layers thick, made of dead keratinocytes that have become flat and clear.
29
This is where they begin to aggregate into arrays called tonofilaments.
30
And lastly, there is the stratum corneum, or horny layer.
31
This outermost section is twenty to thirty cell layers thick, and all of these cells are anucleated, meaning the nucleus has disintegrated.
32
So it’s incredible to think that all the cells covering the outside of your body are actually dead, but they are dead in a specialized way, with thick plasma membranes surrounding lots of keratin.
33
These dead cells protect all the living ones inside from all the outside dangers.
34
With the epidermis covered, let’s go a little deeper and talk about the dermis.
35
This is made of strong and flexible connective tissue, and is full of nerves and blood vessels.
36
This is also where hair follicles begin.
37
The dermis has two sections, the papillary layer, and the reticular layer.
38
Descending from the epidermis we enter the papillary layer, which is very thin, made of areolar connective tissue and a loose network of collagen and elastic fibers.
39
This leaves room for defensive cells to patrol the area for bacteria that may have made it through the skin.
40
The word papillary refers to the projections from the surface of this layer, which are called dermal papillae, that stick out into the epidermis above.
41
These contain lots of tactile cells as described previously.
42
In areas where there is lots of friction, like the hands, these papillae sit on mounds called dermal ridges, which cause ridges in the epidermis as well, which are meant to enhance the gripping ability of the fingers, and they are visible as the lines on our fingertips that make our unique fingerprints.
43
Below this papillary layer sits the reticular layer, which is most of the dermis, and it is made of dense fibrous connective tissue that is arranged irregularly.
44
A network of blood vessels sits below this, just before the hypodermis.
45
What else can we say about the skin?
46
We mentioned that the stratum basale also contains melanocytes, which produce melanin.
47
This is a pigment molecule, and this is one of the components of the skin that determines its color, and protects the skin from ultraviolet radiation.
48
The other pigments responsible for skin color are carotene, which is yellow-orange, and hemoglobin, which is red when oxygenated.
49
We will discuss this molecule in more depth later in the series.
50
That wraps things up for the skin, so let’s just briefly touch on the other components of the integumentary system, which are called skin appendages.
51
First, there is hair.
52
Of course most of us have lots of hair on our heads, but there is also hair all over the body, including eyelashes and nose hairs, and these all have specific protective functions.
53
So what is a hair made of exactly?
54
As it turns out, a hair is a flexible strand made largely of dead, keratinized cells.
55
This is hard keratin, which is a bit different from the soft keratin found in cells of the epidermis, which makes them more durable, and not as flaky.
56
Hairs are produced by hair follicles.
57
These possess a root, which is the part deep inside the follicle where keratinization is happening, and a shaft, the part closer to the surface of the skin and then extending outside the body, where keratinization is complete.
58
The hair itself consists of three layers of cells.
59
The innermost is the medulla, containing large cells and soft keratin.
60
Next is the cortex, which is several layers of flattened cells.
61
And lastly there is the cuticle, which is a single layer of overlapping cells, the most keratinized cells in the hair.
62
As for the follicle the hair sits in, this also has some structure to it.
63
In general, a hair follicle is a pocket that folds down from the surface of the epidermis down into the dermis, about four millimeters below the surface.
64
The deep end then expands slightly to form a hair bulb.
65
A bundle of nerve endings attach to the bulb and act as a receptor, responding to any bending of the hair and alerting the brain in case an insect is there, or something of the like.
66
A little bit of dermal tissue called a hair papilla protrudes into the bulb, which supplies signals and nutrients to the hair so it can grow.
67
The wall of each follicle has a few layers.
68
The outermost is the peripheral connective tissue sheath, derived from the dermis.
69
Next is the glassy membrane, derived from the basal lamina.
70
And then there is the innermost epithelial root sheath, derived from the epidermis.
71
This last section has an external part and an internal part, which thins as it approaches the bulb.
72
The cells that actively divide are found in the hair matrix, which push existing cells upwards as they divide, causing the hair to grow.
73
In addition, each follicle has an arrector pili.
74
This is a small bundle of muscle cells that can contract and pull the follicle in such a way that the surface of the skin dimples out, producing what we refer to as goose bumps, when cold or afraid.
75
Our body hair is pretty sparse so this no longer serves much purpose, but for much furrier mammals it is an important defense mechanism for trapping heat and intimidating enemies.
76
Hair can either be vellus hair, which is pale and fine, or terminal hair, which is darker and more coarse, like hair of the eyebrows and scalp.
77
The nails found on our fingers and toes are also part of the integumentary system.
78
These are products of a modification of the epidermis.
79
Just like with hair, in contrast to the soft keratin of the skin, nails contain hard keratin, making them great tools for scratching or picking up objects.
80
Each nail has a free edge, which is the very tip, then a body, which is most of what we see, and then a proximal root, which is embedded in the skin.
81
The part of the epidermis the nail sits on is called the nail bed, and the nail grows out of the nail matrix, which pushes the nail outwards across the nail bed as these cells divide.
82
There are also skin folds overlapping the borders of the nail which are called nail folds, sitting on the lateral and proximal borders, and the latter extends onto the nail as the eponychium.
83
At the edge of the finger is the hyponychium, where dirt tends to collect.
84
The last part of the integumentary system we must mention is the vast collection of glands that can be found.
85
First up are the sweat glands, also known as sudoriferous glands.
86
These are found almost everywhere on the surface of the skin, totalling up to around three million.
87
There are two types of sweat glands.
88
The first is called eccrine, or merocrine sweat glands.
89
Most of them are of this type, and it consists of a coiled tube.
90
Secretion occurs in the dermis, and the resulting fluid, or sweat, travels through the tube towards a funnel-shaped opening called a pore.
91
Sweat is ninety-nine percent water, but it contains some salts and metabolic wastes, among other things.
92
Sweat is also secreted by apocrine sweat glands, which are far fewer, found only in certain areas, and secrete fat and protein components along with the normal mixture, which is the cause of body odor.
93
Ceruminous glands and mammary glands are also types of apocrine glands, which produce earwax and breast milk.
94
Beyond sweat glands there are sebaceous glands, also known as oil glands.
95
These are branched alveolar glands that secrete sebum, which is made of oily lipids.
96
This will soften and lubricate hair and skin, slowing water loss and killing certain bacteria.
97
So that covers the basics of the integumentary system, which consists of skin, hair, nails, and glands.
98
This system acts a barrier, separating what’s outside of us from what’s inside of us.
99
It has the ability to repair quickly, regulate body temperature, and respond to stimuli outside of the body, among other things.
100
Now that we have this system covered, let’s head inside the body and check out the rest.
アプリをダウンロード
流暢に話すために必要なすべて
AI発音採点文ごとに採点
IPA練習すべての音をマスター
単語学習自分の単語帳を作る
単語ゲーム遊びながら覚える
同じチャンネル
C11
The Composition and Function of Blood
Daily ConversationUniversity Students
C14
Convergence and Divergence: The Return of Sequences and Series
American AccentCambridge Exam PrepUniversity StudentsWorking Adults
C221
CRISPR-Cas9 Genome Editing Technology
American AccentIELTS PrepTOEFL PrepUniversity Students
B2Introduction to Chemistry
American AccentDaily ConversationHigh School StudentsUniversity Students
C1What is a Crime? (The Six Types of Crimes)
American AccentIELTS PrepTOEFL PrepUniversity Students
B2Addition and Subtraction of Small Numbers
American AccentDaily ConversationHigh School StudentsUniversity Students
FOR YOU
おすすめ動画
C11
69 文
Tissues, Part 1: Crash Course Anatomy & Physiology #2
Cambridge Exam PrepUniversity StudentsWorking Adults
B23
67 文
Mastering the Art of Hair Removal
American AccentBusiness EnglishDaily ConversationUniversity Students
C14
34 文
The Evolution of Human Skin Colour | BBC Earth Science
IELTS PrepTOEFL PrepUniversity Students
C110
197 文
English Daily Life Conversation - Factory Safety - Advanced English Practice with Vocabulary Review
American AccentBusiness EnglishDaily ConversationUniversity Students
C23
32 文
Intestinal Villi
University StudentsWorking Adults
C11
43 文
What is an Organization? - the Nature of Organizations
Business EnglishUniversity StudentsWorking Adults
C23
132 文
Das Immunsystem erklärt
University StudentsWorking Adults
C22
160 文
Breast Pathology Cases 3 and 4
University StudentsWorking Adults
B22
166 文
what i eat for GUT HEALTH & CLEAR SKIN | anti-inflammatory, simple meals
American AccentBusiness EnglishDaily ConversationUniversity Students
C13
81 文
Everything You Need to Know About DNS: Crash Course System Design #4
Daily ConversationUniversity StudentsWorking Adults
C147
12 文
Why Do We Itch?
IELTS PrepTOEFL PrepUniversity Students
このレッスンについて
このレッスンでは、外部環境から身体を守る重要な役割を果たしている「皮膚系」について学びます。皮膚の構造や機能、そして皮膚に関連する様々な付属物を理解することで、英語での生物学の基本的な用語を習得しましょう。この知識は、特にYouTubeで英語学習やIELTS スピーキング対策を行う際に役立つでしょう。
重要な語彙とフレーズ
- Integumentary system（皮膚系）
- Skin（皮膚）
- Epidermis（表皮）
- Dermis（真皮）
- Keratinocytes（角化細胞）
- Melanin（メラニン）
- Dermal papillae（真皮乳頭）
- Tactile cells（触覚細胞）
練習のコツ
このレッスンの音声は少し速めですが、英語シャドーイングを行うことで、聴解力と発音を向上させることができます。まずは、動画を視聴しながら内容を理解してください。その後、映像の音声を聞き取りながら、同じタイミングで声に出してみましょう。特に、英語の発音を良くするために、正確な音声のリズムやイントネーションに注目してください。少しずつ慣れることで、shadow speechが自然にできるようになります。また、難しい部分は繰り返し聞くことで、理解を深めましょう。
この動画の文法
話し手がよく使っている文型を、動画の実際の表現とともに紹介します。
| 文型 | 動画での表現 |
|---|---|
| 受動態 be + 過去分詞 — 誰がするかより、何が起きるかに焦点を当てる | is called · is made · is vascularized |
| 関係詞節 who / which + 節 — 人や物について情報を加える | system, which is · layer, which is · dermis, which is |
| 現在完了形 have/has + 過去分詞 — 過去の出来事が今も関係している | have become · has disintegrated |
シャドーイングとは？英語上達に効果的な理由
シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。