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In this video, I want to introduce the different types of neural cells.
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The word neural, or the prefix neuro, just refers to the nervous system, so that neural cells are cells of the nervous system.
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Neural cells work with all the other cell types of the
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body to produce the amazing range of functions of the nervous system, including consciousness, social interactions, cognition,
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emotion, movement, sensory perception, and regulation of other functions such as circulation, respiration, and digestion.
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Neural cells are divided into two big categories.
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The first are neurons, which were traditionally called nerve cells.
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And the second are glia.
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Now these can also be called neuroglia or glial cells.
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That all means the same thing.
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Neurons are named from a Greek word for nerve, while glia are named from a Greek word for glue because they are once thought to do little except glue neurons together.
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The structure of the nervous system is divided into two main parts.
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The first part is mainly made up of the brain in the head and the spinal cord in the spine.
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And this part of the nervous system is called the central nervous system.
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The other part of the nervous system is called the peripheral nervous system.
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And that's made up mostly of nerves, these long stringy structures that come out of the brain and the spinal cord.
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And they go all over the body, like down into the arms and down into the legs and into every part of the body.
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And we'll cover a lot more detail about neuroanatomy in other videos, but I just need to bring up the central
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and peripheral nervous system because the neural cells are divided up differently amongst the different systems.
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Calling neurons nerve cells is a little problematic
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because these structures in the peripheral nervous system called nerves are made up of neurons, but they also contain glial cells,
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and they contain a number of other cells that aren't neural cells at all.
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However, you'll often hear people refer to neurons as nerve cells because that was the traditional name for them.
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Neurons are found both in the central nervous system, the brain and the spinal cord, and the peripheral nervous system, in the nerves.
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But the different types of glial cells are found only in one or the other.
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Most neural cells are derived from populations of cells called neural stem cells or neural crest cells.
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And both of those cell types arise early in development in the part of the embryo called the ectoderm.
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Most neurons in glia found in the central nervous system are derived from neural stem cells,
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while most neurons in glia found in the peripheral nervous system are derived from neural crest cells.
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Now we'll go into a lot more detail about what neural stem cells are
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and neural crest cells in other videos when we cover development of the nervous system.
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Most types of both neurons and glia share some structural features of the way their cell is shaped.
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Most of them have a main part to their cell called the soma, or the cell body, that contains the nucleus and most of the organelles.
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Coming out of the soma, most of these cell types have processes, long, thin extensions that come out of the soma.
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And the processes of the different neural cells vary in number and in length and thickness and degree of branching, because some of them will be unbranched,
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and some of them will have processes that branch, sometimes a little and sometimes a lot.
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They will also vary a lot in the terminal structures at the end of their processes
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and the function of these structures and the processes.
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The function of neurons is to process and transmit information, and the function of glia is to support them in a variety of ways.
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There are many structural and functional types of both the neurons and the glia, And there are large numbers of these cells making up the nervous system.
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There are billions of neurons that form trillions of connections in the adult human nervous system.
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And there are even more glia than there are neurons.
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In subsequent videos, we'll go over the most common glia, which are astrocytes, microglia, ependymal cells, oligodendrocytes, and Schwann cells.
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There are also less common glia, such as satellite cells and olfactory and sheathing cells.
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But we'll just go over the most common types here.

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Questo video contiene 45 frasi e 742 parole da ripetere con lo shadowing. Il parlato dura 4:10. Chi parla ha un ritmo naturale di circa 178 parole al minuto, vicino a una conversazione quotidiana. Solo il 77% delle parole rientra nelle 3.000 più comuni dell’inglese, quindi il lessico è impegnativo.

Vocaboli chiave di questo video

15 parole del video che vale la pena imparare, con pronuncia e significato:

ParolaPronunciaSignificato
neural aggettivo/ˈnʊɹəl/neurale
nerve sostantivo/nɝv/nervo
peripheral aggettivo/pəˈɹɪf(ə)ɹ(ə)l/periferico
stem sostantivo/stɛm/ceppo, ramo
divide verbo/dɪˈvaɪd/dividere, dividersi
cord sostantivo/ˈkoɹd/cordone
spinal aggettivo/spaɪ.nəl/spinale
crest sostantivo/kɹɛst/cresta
derive verbo/dɪˈɹaɪv/derivare
refer verbo/ɹɪˈfɜː/riferire
vary verbo/ˈvɛəɹi/variare
structural aggettivo/ˈstɹʌk(t͡)ʃəɹəl/strutturale
glue sostantivo/ɡlu/colla
thin aggettivo/ˈθɪn/sottile, fine
extension sostantivo/ɪkˈstɛnʃən/proroga, estemsione

I phrasal verb che sentirai

ParolaPronunciaSignificato
make up verbo/ˌmeɪk ˈʌp/comporsi
bring up verbomenzionare, nominare

Pronuncia a cui fare attenzione

Chi parla usa 6 contrazioni e forme ridotte, come we'll, aren't, you'll. Pronunciale nella forma breve, così come le senti.

  • I suoni “th”: thin /ˈθɪn/, thickness /ˈθɪknəs/, sheath /ʃiθ/
  • I suoni “sh” e “zh”: structural /ˈstɹʌk(t͡)ʃəɹəl/, extension /ɪkˈstɛnʃən/, regulation /ˌɹɛɡjʊˈleɪʃən/, interaction /ˌɪn.təˈɹæk.ʃən/, emotion /ɪˈməʊ.ʃən/
  • Parole lunghe — attenzione all’accento: peripheral /pəˈɹɪf(ə)ɹ(ə)l/, regulation /ˌɹɛɡjʊˈleɪʃən/, interaction /ˌɪn.təˈɹæk.ʃən/, differently /ˈdɪf.ə.ɹənt.li/, traditionally /tɹəˈdɪʃ.ə.nə.li/

Come esercitarsi con questo video

  1. Ascolta tutto il video una volta senza parlare e annota le parole che non conosci.
  2. Inizia a velocità 0,75×, fai shadowing frase per frase e torna alla velocità normale quando diventa facile.
  3. Registrati e confronta con l’originale, facendo attenzione a parole come neural, nerve, peripheral.

La grammatica di questo video

Le strutture che chi parla usa di più, con le parole esatte del video:

StrutturaNel video
Forma passiva be + participio passato — conta ciò che accade, non chi lo faare divided · be called · are named
Frasi relative who / which + frase — un’informazione in più su una persona o una cosaneurons, which were · glia, which are

Cos'è la tecnica dello Shadowing?

Shadowing è una tecnica di apprendimento delle lingue supportata da studi scientifici, originariamente sviluppata per la formazione dei traduttori professionisti e resa popolare dal poliglotta Dr. Alexander Arguelles. Il metodo è semplice ma potente: ascolti un audio in inglese di madrelingua e lo ripeti immediatamente ad alta voce — come un'ombra che segue il parlante con un ritardo di solo 1–2 secondi. A differenza dell'ascolto passivo o degli esercizi di grammatica, lo shadowing costringe il tuo cervello e i muscoli della bocca a elaborare e riprodurre simultaneamente i modelli di discorso reale. La ricerca dimostra che migliora significativamente la precisione della pronuncia, l'intonazione, il ritmo, il discorso connesso, la comprensione dell'ascolto e la fluidità del parlato — rendendolo uno dei metodi più efficaci per la preparazione alla prova di speaking dell'IELTS e per la comunicazione reale in inglese.

Tecnica dello shadowing: leggi la guida completa passo dopo passo →