🥇 PLEXO BRAQUIAL. (Constitución, Troncos, Ramas). Fácil y Sencilla

Summary

En este video educativo, Juan José Sánchez aborda la anatomía del plexo braquial, un tema solicitado frecuentemente y desafiante para estudiantes de salud. El plexo braquial es una red de nervios que provienen principalmente de la columna cervical y se dirigen hacia el brazo, proporcionando innervationes y movimiento al miembro superior. Sánchez explica de manera clara y detallada la formación del plexo braquial a partir de las ramas anteriores de los nervios C5 a D1, y cómo se dividen en troncos primarios, divisiones primarias y secundarias, y finalmente en ramas terminales. Destaca la relación estrecha del plexo con las arterias subclavia y axilar, y menciona las ramas finales que incluyen el nervio musculocutáneo, mediano, ulnar y radial, cada uno con su propia función específica en la innervation de los músculos del brazo y antebrazo. Además, menciona la innervation simpática del plexo braquial y cómo se relaciona con los ganglios cervicales. El video es una herramienta valiosa para aquellos que buscan entender mejor la compleja red del plexo braquial.

Takeaways

• 🧠 El plexo braquial es una red de nervios que proviene principalmente de la médula espinal cervical y se dirige al miembro superior.
• 🔍 Se forma por la unión de las ramas anteriores de los nervios C5 a D1, y a veces recibe contribuciones de C4 o D2.
• 🌐 El plexo braquial está en relación estrecha con la arteria subclavia y axilar, y se encuentra en la región del triángulo posterior del cuello.
• 💡 Se divide en tres troncos primarios: superior, medio y inferior, que se forman por la unión de las ramas anteriores de los nervios cervicales.
• 🔑 Los troncos primarios se dividen en seis divisiones primarias: tres anteriores y tres posteriores, que luego se unen para formar los troncos secundarios.
• 🚀 Los troncos secundarios son el tronco lateral, el tronco posterior y el tronco medial, cada uno de los cuales da lugar a una serie de ramas y, finalmente, a las ramas terminales.
• 🏃 Los músculos del pecho, como el pectoral mayor y el pectoral menor, reciben innervationes de las ramas del plexo braquial.
• 💪 El nervio musculocutáneo, una de las ramas terminales, innerva los músculos anteriores del brazo, incluyendo el coracobrachial, el bíceps y el braquial.
• 👐 El nervio mediano, formado en parte por el tronco secundario lateral, innerva los músculos de la eminencia thenar y la mayoría de los músculos anteriores del antebrazo.
• 🛤 El nervio radial, el más grueso del plexo braquial, innerva todos los músculos posteriores del brazo y el antebrazo.
• 🤲 El nervio ulnar, una de las ramas terminales, innerva dos músculos del antebrazo, así como los músculos de la eminencia hypothenar y la mayoría de los músculos cortos de la mano.

Q & A

¿Qué es el plexo braquial y qué partes del cuerpo afecta?

El plexo braquial es una red de nervios que se origina principalmente en la columna cervical y se dirige hacia el miembro superior, proporcionando la innvación y el movimiento al brazo.

¿Cuáles son las partes a través de las cuales emerge el plexo braquial?

El plexo braquial emerge entre el músculo escaleno anterior y el músculo escaleno medio, y está cubierto en dirección anterolateral por el músculo esternocleidomastoideo.

¿Cómo se relaciona el plexo braquial con la arteria subclavia y la arteria axilar?

El plexo braquial tiene una relación muy íntima con la arteria subclavia, específicamente con su segunda y tercera porción, y con la arteria axilar a lo largo de todo su recorrido.

¿Cuáles son las raíces nerviosas que componen el plexo braquial?

El plexo braquial está compuesto por las raíces nerviosas del nervio C5 hasta el nervio D1, que son las ramas anteriores de estos nervios.

¿Cómo se forman las tres divisiones primarias del plexo braquial?

Las tres divisiones primarias del plexo braquial son las troncos primarios superior, medio e inferior. El tronco superior se forma por la unión de las ramas anteriores de los nervios C5 y C6, el tronco medio por la rama anterior del nervio C7 solo, y el tronco inferior por la unión de las ramas anteriores de los nervios C8 y D1.

¿Cuáles son las divisiones secundarias del plexo braquial?

Las divisiones secundarias del plexo braquial son los troncos secundarios, que incluyen el tronco anteroexterno o lateral, el tronco posterior y el tronco anterointerno o medial.

¿De qué manera se relacionan las divisiones del plexo braquial con la arteria axilar?

Las divisiones del plexo braquial se refieren en relación con las porciones de la arteria axilar; los troncos secundarios se envuelven alrededor de las porciones de la arteria axilar.

¿Qué nervios son los que surgen de la rama anteroexterna del plexo braquial?

La rama anteroexterna del plexo braquial da lugar al nervio pectoral mayor, que innvava el músculo pectoral mayor, y también da una rama comunicativa con el nervio pectoral menor. Además, forma el nervio musculocutáneo y la raíz del nervio mediano.

¿Cuáles son las ramas del nervio posterior del plexo braquial?

El nervio posterior del plexo braquial da lugar a tres nervios: el nervio subscapular superior, el nervio subscapular medio (también conocido como nervio del músculo latissimus dorsi o nervio torácico dorsal) y el nervio subscapular inferior.

¿Qué músculos innvava el nervio radial?

El nervio radial es el nervio más grueso del plexo braquial y innvava todos los músculos posteriores del brazo y del antebrazo.

¿Cuáles son las ramas cutáneas del plexo braquial?

Las ramas cutáneas del plexo braquial incluyen el nervio cutáneo brachial medial, el nervio cutáneo antebrachial medial y el nervio cutáneo posterior del antebrazo.

¿De qué manera recibe el plexo braquial su innvación simpática?

El plexo braquial recibe su innvación simpática de los ganglios del tronco simpático, incluyendo el ganglio cervical medio, el ganglio cervical vertebral y el ganglio torácico cervical.

Outlines

00:00

😀 Introducción al Plexo Brachial

Juan José Sánchez inicia el video presentándose y anunciando el tema, el plexo brachial, una estructura complicada y demandante para los estudiantes de salud. Él promete abordar el tema de una manera fácil y agradable, y alienta a los espectadores a suscribirse para obtener más contenido relacionado.

05:00

🔍 Composición y Origen del Plexo Brachial

Se describe el plexo brachial como una red de nervios que provienen principalmente de la columna cervical, específicamente de los nervios C5 a D1. Se menciona la contribución adicional de los nervios C4 y D2 en algunas variaciones anatómicas. Se detalla la formación de las tres divisiones primarias del plexo: las troncos superior, medio e inferior, y cómo se originan de las uniones de los nervios cervicales correspondientes.

10:08

🤚 División y Desarrollo de las Ramas del Plexo Brachial

Se explica cómo las divisiones primarias del plexo brachial se ramifican en seis divisiones secundarias, formando las ramas anteriores y posteriores de cada tronco primario. Luego, estas divisiones se unen para formar las tres troncos secundarios: lateral, posterior y medial. Se destaca la relación estrecha del plexo brachial con la arteria subclavia y axilar a lo largo de su trayectoria.

15:12

🏃 Ramas Terminales y Innvación del Plexo Brachial

Se nombran las ramas terminales del plexo brachial, que son los nervios que surgen al final de sus divisiones. Se discuten las funciones de cada una de estas ramas, incluyendo la innvación de músculos específicos del hombro, brazo, y bíceps, así como la formación de las ramas cutáneas que sirven la piel en diferentes áreas. Se mencionan nerves como el nervio musculocutáneo, la médula radial, y el nervio ulnar, y su importancia en la innvación de los músculos y la piel.

20:16

🤝 Innvación Simpática y Conclusión

Se concluye el video describiendo la innvación simpática del plexo brachial, que recibe contribuciones de los ganglios cervicales. Juan José Sánchez invita a los espectadores a suscribirse, dar like al video y seguirlo en Instagram para mantenerse actualizado con más contenido anatómico.

Keywords

💡plexo braquial

El plexo braquial es una red de nervios que proviene principalmente de la columna vertebral cervical y se dirige hacia el miembro superior. Es fundamental para el movimiento e innvación del extremo superior. En el video, se describe cómo este plexo se forma a partir de las ramas anteriores de los nervios cervicales desde C5 hasta D1, y su importancia para la anatomía y la función del brazo.

💡raíz del nervio

Las raíces de los nervios son las divisiones que surgen de la médula espinal y se unen para formar plexos nerviosos. En el contexto del plexo braquial, las raíces son las ramas anteriores de los nervios cervicales C5 a C8 y el nervio dorsal T1, que contribuyen a la formación del plexo.

💡troncos primarios

Los troncos primarios son las divisiones principales del plexo braquial, formados por la unión de las raíces nerviosas. El video menciona tres troncos primarios: superior, medio e inferior, cada uno de los cuales se relaciona con los nervios cervicales y el nervio dorsal T1 y da lugar a divisiones y ramificaciones adicionales.

💡divisiones del tronco primario

Cada tronco primario se divide en dos divisiones: una anterior y una posterior. Estas divisiones son fundamentales para la formación de las ramas del plexo braquial. El video describe cómo cada una de estas divisiones da lugar a ramas que eventualmente se unen para formar los troncos secundarios.

💡troncos secundarios

Los troncos secundarios son las divisiones que surgen de las divisiones anteriores del tronco primario. Se forman por la unión de las divisiones anteriores y se organizan en troncos anterolateral, posterior y anteromedial. Estos troncos son cruciales para la distribución de las funciones innervativas en el miembro superior.

💡ramas terminales

Las ramas terminales son las últimas divisiones del plexo braquial que se ramifican para innvvar diferentes grupos musculares y áreas de la piel. El video menciona que estas ramas incluyen al nervio musculocutáneo, el nervio mediano y el nervio ulnar, entre otros, que son esenciales para el movimiento y la sensación en el brazo y el antebrazo.

💡nervios contribuyentes

Los nervios contribuyentes son nervios que se unen al plexo braquial y amplían su capacidad innervadora. En el video se discute cómo el plexo braquial puede recibir contribuciones adicionales de nervios cervicales C4 y D2, lo que puede influir en su forma y función.

💡forma del plexo braquial

La forma del plexo braquial es un aspecto clave de su anatomía, ya que afecta cómo se relaciona con otras estructuras y cómo se ramifica. El video describe cómo el plexo se organiza en troncos y ramas, y cómo su estructura se relaciona con la artería subclavia y la artería axilar.

💡innvación muscular

La innvación muscular se refiere a la provisión de nervios a los músculos para permitir su收缩 (contracción) y movimiento. El plexo braquial es esencial para la innvación de múltiples músculos del brazo y antebrazo, como se describe en detalle en el video.

💡ganglio simpático

Los ganglios simpáticos son grupos de células nerviosas que forman parte del sistema nervioso autónomo. En el contexto del plexo braquial, el video menciona que el plexo recibe contribuciones de los ganglios simpáticos cervicales medios y vertebral cervical, lo que afecta la actividad de los órganos internos y la respuesta del cuerpo a las emociones.

💡articulaciones del hombro

Las articulaciones del hombro, aunque no explícitamente mencionadas en el video, son importantes en la función del plexo braquial, ya que muchos de los nervios que salen del plexo son responsables de la movilidad y la sensación en las articulaciones del hombro y del codo.

Highlights

Juan José Sánchez presenta un video sobre la anatomía del plexo braquial, un tema solicitado frecuentemente y desafiante para los estudiantes de salud.

El plexo braquial es una red de nervios que proviene principalmente de la columna cervical y se dirige hacia el miembro superior.

Se forma por la unión de las ramas anteriores de los nervios C5 a D1, incluyendo a veces la contribución de C4 o D2.

El plexo braquial tiene una relación estrecha con la arteria subclavia y la arteria axilar a lo largo de su trayectoria.

Se divide en tres troncos primarios: superior, medio y inferior, en relación con la porción de la arteria subclavia.

Los troncos primarios se subdividen en ramas anteriores y posteriores, formando seis divisiones en total.

Las divisiones anteriores de los troncos primarios se unen para formar los troncos secundarios, conocidos como lateral, posterior y medial.

Los troncos secundarios darán lugar a las ramas terminales del plexo braquial, que innervan diferentes músculos del miembro superior.

El nervio dorsal de la escápula, también conocido como nervio romboide, proviene de la rama de C5.

El nervio torácico largo, también llamado nervio del serrado anterior, se forma por ramas de C5, C6 y C7 y innerva el músculo serrado mayor.

El nervio supraescapular innerva los músculos supraespinoso e infraespinoso y proviene del tronco primario superior.

El nervio pejorotoideo mayor y el nervio pejorotoideo menor se derivan del tronco secundario lateral y se unen mediante una rama comunicativa.

El nervio musculocutáneo, el más lateral del plexo braquial, innerva los músculos anteriores del brazo.

La médula nerviosa se forma por dos raíces, incluyendo una proveniente del tronco secundario lateral.

El nervio circumflejo, también conocido como nervio axilar, y el nervio radial son las ramas terminales más destacadas del tronco secundario posterior.

El nervio ulnar proviene del tronco secundario medial y innerva dos músculos del antebrazo y la mayoría de los músculos cortos de la mano.

El plexo braquial recibe innervation simpática de los ganglios del cuello, incluyendo el ganglio cervical medio y el ganglio cervical vertebral.

Sánchez resalta la importancia del conocimiento del plexo braquial para la comprensión de la innervation del miembro superior.

Transcripts

Welcome to a new anatomical video, easy, my name is Juan José Sánchez,

today we will talk about the anatomy of the brachial plexus, this is a video that has been requested of me

a lot, it is a torment for every health student to learn the brachial plexus, so

today I will try to bring it to you in a very easy way, in a pleasant way and in a

very quick way to learn, before starting to explain I invite you to subscribe to my channel, here in

the lower corner Right, click on it, click subscribe and this way you will be able to access more content,

more videos from this channel and they will help me a lot to grow, so first starting with the

anatomy of the brachial plexus, it is important to know that when we talk about the plexus in general ,

we talk about a network, that is, a union, this network can be venous, that is, a confluence of

several veins, it can be arterial, several arteries that join together, or it can simply be nerves,

specifically when we talk about the brachial plexus, we are then talking about a nervous network, that is,

nerves that go to the brachium, a brachium that refers to the arm, that is, it is what carries the

movement, the innervation to the upper limb, the brachial plexus is a network that originates at the level

of the cervical spine mainly, then anatomically in this lateral view of the neck

we are going to see here that it is shaded in green, which emerge from the vertebral column through the

intervertebral foramina, passes through the neck and from there they go towards the upper limb,

basically When it emerges it will pass between two muscles, between this one that we see

here which is the anterior scalene muscle and this one that we see here which is the middle scalene muscle,

in addition to that it will be covered in an anterolateral direction by this muscle which would be

the sternocleidomastoid, once it emerges between the anterior and middle steps it is

crossed by the lower belly of this muscle that we see here, which is the omohyoid muscle,

this emergence is the most superficial part of the brachial plexus and is basically located

in the posterior triangle of the neck, more specifically in its upper division

which would be the posterior occipital triangle of the neck, now here we see the brachial plexus well

schematized, we see this muscle that is here which is the anterior scalenus and this one that

is seen here behind the middle scalenus, We see how the anterior roots of those cervical nerves

that make up my brachial plexus then emerge between the anterior scalene and the middle scalene.

This muscle that we see cut here is precisely the lower belly of the omohyoid, as I told you

it would be the same one that is here, that crosses and covers in an anterolateral direction what is

the beginning of the brachial plexus, we see that this brachial plexus is in a deep relationship

first with the subclavian artery and then with the axillary artery, remember that the subclavian

becomes an axillary artery when it passes by the external edge of the first rib,

then it is a very intimate relationship with the subclavian, specifically with its second and third

portion and with the axillary artery throughout its entire journey, now we see here in this image,

this lateral view as this artery that It is part of the thyrocervicoscapular trunk of the subclavian,

this is the transverse cervical artery, it crosses laterally what is the brachial plexus in

its course, now how is this brachial plexus going to be formed? Do not be scared by this

image, which is a diagram, but it shows very well what the formation of the brachial plexus is like.

First, the brachial plexus is made up, as you see here, of five nerve roots. The first root, which is

the most superior, is the anterior branch. of the c5 nerve, remember that every nerve that emerges from the

spinal cord gives an anterior branch and a posterior branch which is this one here, always the plexuses that you

are going to hear in anatomy are all products of anterior branch units, that is, the posterior branches

will never form the plexus, so it is formed by the union of the anterior branch of c5,

anterior branch of the c6 nerve, anterior branch of the c7 nerve, anterior branch of the c8 nerve and this is where

the cervical nerves reach, remember that they are seven cervical vertebrae, this would be c5,

this would be c6, this would be c7, but there are eight cervical nerves, for an anatomical reason, so

after c8, its anterior branch would come the dorsal thoracic nerves, then only the

first dorsal nerve which we are going to call d1, but you already know that it can also be called t1,

d for dorsal and t for thoracic, it helps to form part of What is the brachial plexus, so that it is

formed by the anterior branches from c5 to d1, this entire union of those five cervical nerves

are what make up the brachial plexus, now this is normal, this is common,

this what is repeated the most but many times we see brachial plexus that receives a contribution from c4,

as you see this branch schematized and many times there are brachial plexuses that receive contribution from d2,

with this branch that you see here schematized, it is not common but it can occur, it is said that

when the brachial plexus has a contribution from c4 it is a pre-formal brachial plexus, that is, it was formed

earlier, higher up, while when it has a lot of d2 contribution, it is said to be a

post-formal brachial plexus, that is which was formed very low down, now this brachial plexus as you see it

there has a very practical way to study it and it is according to some divisions that it has,

so I remind you again of the formation from the anterior branches of c5 to the

anterior branches of d1, there are 5 divisions that we are going to do, first, the first

branches that the brachial plexus gives are when it is not yet a plexus, that is, these are still the

anterior branch c5, there is the anterior branch of c6 and there is that of c7 , of c8 and that of d1, there it is not plexus, what

plexus is it when they join, then there is a twig that are branches of those previous branches,

but that are not part of the brachial plexus itself, however we study them as branches of the brachial plexus

but you already know that theoretically they are not branches of the brachial plexus, then when

these anterior branches join together they make up the brachial plexus and these first three branches that

you see here are what we call primary trunks ok, they are the primary trunks

of the brachial plexus, then these would be the anterior branches from c5 to d1, this is what

I shade them in black, then come the primary trunks that will be three, this would be the

upper primary trunk, this would be the middle primary trunk And this would be the lower primary trunk,

that is, they will be superior, middle and inferior, with respect to who I call it that? Well, with

respect to the second portion, some books say third portion, of the subclavian artery,

it is very important to know that the lower primary trunk rests on the first rib,

so much so that it is even a groove, so the correct name is primary trunk

upper, middle primary trunk and lower primary trunk, now it is very important that you

know how these primary trunks are formed, it is a very easy way, the anterior branch of c5 with

the anterior branch of c 6 form the upper primary trunk, as well as You see here in the image,

then everything that emerges or most of the things that emerge from the upper primary trunk

will have a contribution from both c5 and c6, the middle primary trunk is formed alone by the

anterior branch of c7, alone It forms the middle primary trunk, while the

lower primary trunk is formed by the union of the anterior branch of c8 and the anterior branch of d1, so you know,

upper primary trunk union of c5 and c6, middle primary trunk of c7 alone and

lower primary trunk the union of c8 with the union of d1, that would be the second division of the brachial plexus which

are the famous upper middle and lower primary trunks, now the third division is going to be the

divisions of those primary trunks, I explain to you so that they are not confused, each primary trunk, that is,

upper, middle and lower, is divided into two branches, these would be the two branches of the upper one,

these would be the two middle branches and these would be the two branches of the lower one, that division in

the primary trunks, as there are two branches for each trunk, they will be one anterior and one posterior,

so that we will have three anterior branches and three posterior branches, the anterior branches are

the ones that I highlight here in green, this would be the anterior branch of the upper primary trunk,

the anterior branch of the middle primary trunk and there is the anterior branch of the lower primary trunk,

while the posterior branches, which will also be three, are these that I underlined

in blue, that is, this series of the branch or the posterior division of the upper primary trunk,

the posterior division of the middle primary trunk and the posterior division of the trunk

lower primary, this would be the third division in general of the brachial plexus,

you know anterior branches primary trunks and we go through the divisions of the primary trunks,

now those branches or those sorry those divisions of those primary trunks join to form the

secondary primary trunks , which will be three, these secondary primary trunks are called

the anteroexternal primary trunk, also called anteroexternal secondary trunk, also

called anterolateral or simply lateral, this would be the posterior secondary trunk and this would then be the secondary trunk

also called anteromedial or simply trunk medial secondary

, now in relation to what I call this external antero, posterior and internal antero? in

relation to the axillary artery, more specifically to the first and second portion of the

axillary artery, that is, they wrap these trunks, branches of the secondary trunk to the portions of

the axillary artery, now, how are these secondary trunks going to be formed? ? I explain to you,

the two unions or the two anterior divisions, that is, that of the upper primary trunk and the

anterior division of the middle primary trunk, join together and form the anteroexternal secondary trunk,

the three posterior divisions, that is, that of the upper one, the lower middle and lower,

the three form the posterior secondary trunk and alone the anterior division of the

lower primary trunk alone forms the anterointernal secondary trunk, those are going to be the secondary divisions, that

is, the secondary trunks, now after those trunks secondary branches

we are going to have the terminal branches that are the last branches that emerge from the brachial plexus, we

will address those branches in another video, I will only explain here what each

of them is and where they come from, but in itself this video is about of the plexus, which are these

first four portions that we see here, however here I will name the final terminal branches

of the brachial plexus, so it is important to know which nerves give each part of the brachial plexus,

it is a very easy analogy, let's say, first the previous branches As I explained to you, they originate three

groups, four groups of nerves, so the branch of the branches of that anterior branch of the

cervical nerves and this middle dorsal are going to be the anterior branches of the spinal nerves,

so we are going to find four groups of branches, as I told you here, first we are going to see

the dorsal scapular nerve, this dorsal scapular nerve is also called the rhomboid nerve,

because it is the nerve that goes precisely to the rhomboid muscles, then we have this

contribution here from c5, c6 and c7, See that the three give a branch that forms a nerve that goes

downwards, that is the long thoracic nerve, this long thoracic nerve is also called

the serratus anterior nerve, or serratus major and it is the one that will innervate the serratus major muscle ,

then you will see that the dorsal scapular only has a contribution from c5, but the long thoracic

from c5, c6 and c7, in addition to that see all these twigs that are cut here that

all the nerves that make up the brachial plexus have, which are the branches that go to

the scalene muscles and the long neck muscles, these would be the small groups of branches

of the anterior spinal branches, now, the primary trunks remember that they were the upper,

middle and lower, they do not give branches, the only one that gives branches of the primary trunk is the

upper primary trunk that gives two branches, the first branch that you see that it is going to give is the

subclavian nerve, this subclavian nerve goes precisely through a muscle that is below the clavicle,

that is above the first rib, which is the subclavian muscle, in addition to this,

a branch can also go through the subclavian nerve to the phrenic nerve and reach what is

the diaphragm, many times the phrenic nerve receives input from this subclavian nerve,

then the next nerve of the upper primary trunk is the suprascapular nerve, this nerve

suprascapular innervates two muscles, which is the supraspinatus muscle and the infraspinatus muscle,

so that these two branches are the only branches of all the first trunks and remember

that it comes out specifically from the upper primary trunk, then we are going to have the divisions of

the trunks primary, remember that they were divided into anterior branches and posterior branches, none of

these divisions of the previous trunks form or rather give, any branch, that

is why I put it here without branches, now we go with the secondary trunks, each secondary trunk gives

a group of branches and through them the terminal branches are going to come out, so I

am going to talk to you below about the branches of those secondary trunks themselves and the terminal branches

that also derive from those secondary trunks, we are going to begin From the lateral to the medial,

first we are going to talk about the anteroexternal secondary trunk or lateral secondary trunk,

the first nerve that you see that it gives is the major pectoralis nerve, it is going to innervate precisely

the pectoralis major muscle but see that from that nerve to The pectoralis major gives off a

communicating branch for this branch that once preceded them, it is the nerve of the pectoralis minor,

so that both pectoral nerves, the lateral one which is also called major and the

medial one which is also called minor pectoralis nerve, They are joined by a branch, now

from whom does that branch receive contributions from the pectoralis major? You see that as c5 and c6 joined together

they will give branches for the pectoralis major but also as it is receiving contribution from the

middle primary trunk and the middle primary trunk in turn is a branch of c7 also c7 helps to form what

that nerve is. of the pectoralis major, within the terminal branches that come out of this

secondary anteroexternal trunk we are going to have two, first the musculocutaneous nerve which is the one

you see here, this musculocutaneous nerve is the one that innervates me, listen well, the anterior muscles

of the arm, which are three, the coracobrachialis, the biceps brachii and the brachialis anterior, the

anterior muscles of the arm are innervated by the musculocutaneous nerve which is the most external,

the most lateral of the brachial plexus, now in addition to that see that the trunk secondary anteroexternal

gives a branch that will later form this nerve, which is the median nerve, which I will talk to you about later

, what I want you to know is that the median nerve is formed by two roots and one of those two

roots is formed by the trunk external antero secondary trunk so that here we finish

external antero secondary trunk, we now go with the posterior secondary trunk, which is the thickest trunk

of the three, because it is the one that receives the most contribution, see that it is formed by the

posterior divisions of the trunks primary, then that secondary posterior trunk first gives rise to

three nerves that are the sub scapular nerves, they are in order, that is, this is the

superior sub scapular nerve, this is the middle sub scapular nerve and this is the

inferior sub scapular nerve, the Superior sub scapular nerve is going to innervate the sub scapular muscle, very easy,

the middle sub scapular nerve, listen well, the middle scapular nerve is also called

the dorsal thoracic nerve or latissimus dorsi muscle nerve, because it is going to innervate precisely

The latissimus dorsi muscle, remember, can be called the dorsal thoracic nerve, the latissimus dorsi nerve

or simply the middle sub scapular nerve, while the inferior sub scapular nerve

also innervates the sub scapular muscle as does the superior one, but in addition to innervating me

The sub scapularis also helps me innervate the teres major muscle, don't forget, both the sub

scapularis and the teres major muscle, sorry the teres minor, it is the one that innervates me, the teres

major is precisely from the suprascapular nerve, which already We name it, teres minor specifically,

now, then this posterior secondary trunk gives me two terminal branches, those two most

terminal branches are going to be, this would be the circumflex nerve that is also called the

axillary nerve, this circumflex nerve that is also It is called the axillary nerve, it helps innervate the

deltoid muscle and finally, the thickest nerve of the entire brachial plexus, which is the radial nerve.

That radial nerve in the end innervates all the posterior muscles, both of the arm

and the forearm, without exception, it has many nerves, many muscles for its function of innervating,

now we are going to move on to the secondary antero-internal trunk, this secondary antero-internal trunk

we are going to To start first with the terminal branches, which are the easiest, they originate the most medial

of all the branches, which is the ulnar nerve. This ulnar nerve helps me innervate

only 2 muscles of the forearm, as well as muscles of the hypothenar eminence. like some

joints of the hand, and innervates most of the short muscles of the hand as well and in addition

to giving the original ulnar nerve the medial branch for the median nerve, so that the

median nerve has a medial branch that comes from the secondary trunk external antero and has a lateral branch

that comes from the external antero secondary trunk and a medial branch that comes from the

internal antero secondary trunk, this median nerve innervates the muscles of the thenar eminence, that is,

that of the thumb, most of the anterior forearm muscles, because remember that the

posterior ones are from the radial nerve, now this median nerve has a contribution from the entire

brachial plexus from c5, c6, c7, c8 and d1, because everyone can see that they give a branch to form the

median nerve , as well as the radial nerve that has a contribution from all the branches of the

brachial plexus, then these are the two terminal branches coming from the

anteroexternal secondary trunk, now three are missing only that it gives when it is still anteroexternal secondary trunk,

first the nerve pectoralis minor, which I told you just now, which was joined by a cord to the nerve

of the pectoralis major, this nerve of the pectoralis minor innervates both the pectoralis minor and the pectoralis

major, unlike the pectoralis major nerve which only innervates the pectoralis

major muscle and then we have the two cutaneous nerves that innervate the skin, the first is the

medial brachial nerve, this medial brachial nerve innervates the skin of the anterior, lateral

and posterior part of the arm, while the next one, which is the medial antebrachial cutaneous nerve, innervates the skin.

the skin of the anterior face and the medial face of the forearm, that is why it is called antebrachial,

so friends here to see basically what the arrangement of the brachial prexus on

the axillary artery is, this would be the most medial one, which is the circumflex, As I told you right now, the

cutaneous muscle, sorry, which is also medial, these would be the two roots that form the median and

this one, the most medial of all, would basically be what the ulnar nerve is, the one you see here

close together are the cutaneous ones, This would be the brachial cutaneous and this would be the antebrachial cutaneous and

this one that you see goes posteriorly which is not seen well there, it would be the radial nerve that became

posterior a long time ago, here in this cross section you see the secondary trunks,

this It would be the most anteroexternal with respect to the axillary, the posterior and the antero internal,

this would be the pectoral branch, this is the pectoralis major and this is the pectoralis minor branch,

now to finish the sympathetic innervation of the brachial plexus, see that it receives contribution from the

ganglion middle cervical, of the cervical ganglion, of the middle cervical ganglion, this one would be the

vertebral cervical ganglion and this one would be the thoracic cervix, the three of sympathetic twigs that

travel through those roots that will later form the brachial plexus, so friends The entire video has already

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