Hello, everyone! This is Joao from Kenhub, and welcome to another anatomy tutorial where we’re going to be talking about the neck neurovasculature and also the lymph nodes that we find in this area of your body.
So what we essentially are going to do is looking at the neck region and then describing the different arteries, veins, nerves, and lymph nodes that we can see here, the main ones that we can clearly find in this region.
And before we do so, I would like to start off with listing the different arteries that we’re going to be talking about on this tutorial.
We’re going to see the common carotid here, the external carotid, the internal carotid, the lingual, the facial artery, the superior thyroid, and also the thyrocervical trunk, the inferior thyroid, the transverse cervical, the ascending cervical, the suprascapular, and the vertebral artery.
Now, before we move on, I would like to make a clarification here on this image. We’re looking at the neck from an anterior or ventral view, and throughout this tutorial, we’re going to see that all of these images are from this perspective. So we’re looking at the anterior view of the neck.
And now that we know that, we’re ready to move on to the very first one on the list, very first arteries on the list, which are known as the common carotid arteries, and you do have two.
These are the biggest and most important arteries of the neck, and one of them, the left one—is from the subject’s perspective, as you can see here—is coming out of the aortic arch, while the right one is branching out of the brachiocephalic trunk.
Now, these two will be, then, used to supply the major part of the head and neck with arterial blood.
The common carotid arteries run below the sternocleidomastoid muscle and then will split up into these two arteries, the internal carotid and the external carotid.
So let’s take a look at, now, these highlights here, the external carotid arteries, which lie laterally from the internal carotid artery and then supply most of the parts that we find on the neck, face, skull, and also dura mater.
And on their way towards the head, they will give off several arteries. The most important will be, then, introduced on the next slides. We’re going to, now, see these highlighted, which are branches of the external carotid artery, and this is the lingual arteries.
These run towards the hyoid bone and then vertically upwards towards the tongue, gives off several small branches for, then, the blood supply of the tongue.
The next ones that you see now, highlighted, are known as the facial arteries, which are branches also of the external carotid artery, cranial from the lingual arteries, which you can also see here on this image particularly.
Now, the facial arteries run behind the submandibular gland, towards the cheek until the eye, and during their course, they’re going to be giving off different branches to the face, hence the name: facial arteries.
Now, one fun fact is that the pulse of the facial artery is easily felt on the edge of the mandible, medially from one important muscle of the… for mastication specifically, known as the masseter muscle.
The next set of arteries that we’re going to see, now, highlighted in green, are known as the superior thyroid arteries, and these are also branches of the external carotid artery. They run towards the thyroid and supplies it with arterial blood.
At that point, the superior thyroid arteries are going to form an anastomosis with, then, the inferior thyroid arteries.
We’re also, now, going to be seeing these that we just briefly mentioned before. These are the internal carotid arteries. They lie medially from the external carotid and supply the anterior part of the brain and also the eyes. They also send off smaller branches towards your nose and forehead.
Now, there is a list of branches that come out of the internal carotid artery that we should list, but I’m going to save it for another tutorial where I’m going to be covering the internal carotid artery with more detail.
We want to focus on the relevant structures for the neck on this video.
Next set that we’re going to be highlighting here that you see, now highlighted in green, are known as the thyrocervical trunks, and another arterial system for the neck besides the carotid arteries is definitely what you see now highlighted, which is the thyrocervical trunks.
They are a large branch of the subclavian artery, and then quickly splits up into three branches, three important branches I must say.
One is the inferior thyroid artery. The other one is the suprascapular artery and the transverse cervical artery.
Let’s have a quick look here at the first branch that I just mentioned, the inferior thyroid artery, and when there is a superior, there should be, then, an inferior thyroid artery.
This one branches out of the thyrocervical trunk.
And remember this. Do not forget that the superior thyroid artery comes out of the external carotid artery.
Do not forget this because, usually, these are exam questions, and do not mix these two structures.
Now, the inferior thyroid artery will be supplying the thyroid with blood, and it lies ventrally to the recurrent laryngeal nerve and is, then, connected to the superior thyroid artery, as I mentioned on previous slides.
Next arteries that we’re going to be seeing here are known as the transverse cervical arteries.
And keep in mind now that this is an image where I’m showing you the dorsal view of the neck.
And I wanted to add here that the transverse cervical artery usually branches off of the thyrocervical trunk. However, it can be a separate branch of the subclavian artery as well.
Now, the transverse cervical artery splits into a superficial branch, running… as you can see here. This is the superficial branch… which runs cranially, and then there is this deep branch which, then, goes caudally.
Now, these transverse cervical arteries will be, then, supplying a few structures, including the trapezius, the rhomboid muscles, the latissimus dorsi, as well as part of the cervical lymph nodes.
And if we turn again back to the anterior view of the neck, you can clearly see here the transverse cervical artery branching out of the thyrocervical trunk.
The next that we’re going to be talking about are these arteries which are known as the ascending cervical arteries. And these are branches of the inferior thyroid artery, but this is variable. It can come directly from the thyrocervical trunk too.
The ascending cervical arteries run vertically upwards, giving smaller branches towards the neck musculature and the cervical spinal cord.
They will also be forming an anastomosis with the ascending pharyngeal artery (another branch of the external carotid artery) and also the occipital artery.
Moving on to, now, talk about the suprascapular artery, which if you remember this is also a branch of the thyrocervical trunk, and as the name suggests, this is found above the shoulder, and these arteries run laterally and supply, then, a few structures, including the sternocleidomastoid, the subclavius muscle, the supraspinatus, and the infraspinatus muscles.
As well as the shoulder and the acromioclavicular joint will be supplied with arterial blood, thanks to this structure, the suprascapular artery.
The last one on that first list of arteries that we had in the beginning, that you now see highlighted in green, these are known as the vertebral arteries.
The vertebral artery is the third big arterial system of the neck besides the carotid arteries and the thyrocervical trunk. These begin as a branch of the subclavian artery.
Now, they run vertically up the neck, squeezing through these holes here, which are known as the transverse foramina of the cervical vertebrae. And then they go into the head and essentially are responsible for the blood supply of the brain as the basilar artery.
We’re now ready to move on to, now, the next list of structures, the veins, that we’re going to be finding on the neck (the main veins), and these include the facial, the external and internal jugular, the inferior, middle, and superior thyroids, and also the vertebral veins.
Let’s start off with the very first one here on the list that we’re going to be seeing, highlighted in green. These are known as the facial veins.
And the facial vein is a relatively large vein in the human face. It lies behind, then, the facial artery.
This vein will be receiving blood from the external palatine vein and either forms the common facial vein or drains directly into the internal jugular vein.
Now, we’re going to move on and talk about a set of two pairs that are known as the jugular veins.
Now, on the left side, we’re looking at the… what are known to be as the external jugular veins, highlighted in green, while on the right side, we’re looking at, then, the internal jugular veins.
Now, the jugular veins are veins that bring deoxygenated blood from the head back to the heart via the superior vena cava. And there are two sets, as I mentioned, of jugular veins: the external and internal jugular veins.
Now, before we move on, I would like to show you a diagram here of these two structures and how they connect to one another and with other structures and show you how they bring deoxygenated blood all the way from the head and neck to, then, your heart.
So, the external jugular veins will be draining into the subclavian veins, and the internal jugular veins will also join with the subclavian veins, more medially to, then, form the other set of veins which are known as the brachiocephalic veins.
Now, finally, the brachiocephalic veins will, then, join the superior vena cava, which then delivers deoxygenated blood to the right atrium of your heart.
We’re now going to move on to the next set of veins that you see here. These are known as the inferior thyroid veins, which are usually appear to be two frequently three or four in number and then communicate with the middle and superior thyroid veins. They will form what is known to be as the plexus in front of the trachea.
Now, these veins will receive blood from the esophageal, tracheal, and inferior laryngeal veins and then drain the deoxygenated blood into the brachiocephalic veins.
There is also what you see here, which are known as the middle thyroid veins, and these will be collecting blood from the lower part of the thyroid gland. And after being joined by some veins from the larynx and trachea, it will, then, drain into the lower part of the internal jugular veins.
Since we have an inferior, middle, we should also have a superior set of thyroid veins. And the superior thyroid veins begin in the thyroid gland, and receive blood from the superior laryngeal and cricothyroid veins, and drains it into the upper part of the internal jugular vein. So this is an important part as well.
Last veins on our list that we’re going to be covering here, these are known as the vertebral veins.
Now, the vertebral vein derives from tributaries that run through the foramina in the transverse processes of the first six cervical vertebrae, and then they will form what is known to be as the plexus around the vertebral artery.
Now, the two vertebral veins receive blood from the deep cervical vein and then drain as a single trunk into the brachiocephalic vein.
And note here, the vertebral vein is highlighted in green and how they form this plexus around the vertebral arteries.
We’re ready to move on to, now, the nerves that we find on the neck region. We’re going to be seeing a cervical plexus, a great auricular nerve, transverse cervical nerve, ansa cervicalis, phrenic nerve, a vagus nerve, and a recurrent laryngeal.
Let’s start off with the very first one that you see here, highlighted in green. This is, then, the cervical plexus. And the cervical plexus is a plexus—a branching network of nerves. This is what we describe as a plexus—of the ventral rami of the first four cervical spinal nerves.
Now, the cervical plexus has two types of branches: cutaneous and muscular. And in this video, we will talk about only the branches that are relevant to the neck area, which include, as the cutaneous branches, the great auricular nerve and the transverse cervical nerve.
As for the muscular branches, we’re going to talk about the ansa cervicalis and also the phrenic nerve.
Nerves formed from the cervical plexus will be innervating the back of the head as well as some neck muscles.
Let’s start off with the very first one here that you see on the list, which is known as the great auricular nerve that you see, now highlighted in green. And the great auricular nerve originates from the cervical plexus, and it provides sensory innervation for the skin over the parotid gland and the mastoid process… and also will be providing sensory innervation for both sides of the outer ear.
The next nerve that we’re going to be talking about that you see now, highlighted in green, these are known as the transverse cervical nerves.
The transverse cervical nerve provides cutaneous innervation to the antero-lateral parts of the neck.
Now, we’re going to be seeing this complex network of nerves which are known as the ansa cervicalis. And the ansa cervicalis is a loop of nerves that are part of the cervical plexus, and it lies superficially to the internal jugular vein in the carotid triangle.
So this is an important point that you need to write on your notes, that this ansa cervicalis will be lying superficially to the internal jugular vein in the carotid triangle.
Now, branches from the ansa cervicalis will be, then, innervating most of the infrahyoid muscles, including the sternothryroid muscle, the sternohyoid muscle, and the omohyoid muscle.
And now, showing you the image of the ansa cervicalis with a bit more structures going on, and you can see how it lies superficially to the internal jugular vein.
And this is, as you can see here, these are the internal jugular veins.
The next structure that we’re going to be talking about, the next nerves are known as the phrenic nerves. And the phrenic nerve is a nerve that originates in the neck at C3 to C5… so, spinal nerves C3 to C5 and passes down between the lung and heart to reach, then, the diaphragm.
And here’s a way to remember its origin and function. If you remember this pneumonic: three, four, five keeps the diaphragm alive. And of course, “three, four, five” referring to the nerves, the spinal nerves that where the phrenic nerve is originating from.
The next one that we’re going to be seeing now, this is also a pair which is known as the vagus nerve, is also known as the tenth cranial nerve.
Now, the fibers of the vagus nerve consist of efferent, motoric, and parasympathetic fibers, and afferent sensory fibers.
Now, the vagus nerve forms part of the involuntary nervous system and helps keep functions happening in your body, including keep the heart rate constant, your heart rate constant, and also controlling food digestion.
Last set of nerves that we’re going to be talking about, that you see now, highlighted in green, these are known as the recurrent laryngeal nerves.
And the recurrent laryngeal nerves is… are branches of the vagus nerve that supply all of the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles, which are supplied by the vagus nerve.
We are now ready to move on and talk about the different lymph nodes that we find on the neck, and there are quite a few. You can see them represented here by these orange dots—you see these structures here—and also these connections. So these are lymph nodes and lymph vessels.
In terms of the list that we’re going to be covering, we’re going to see submental, submandibular, superficial cervical, anterior and lateral internal jugular, juguloomohyoid. We’re going to also see supraclavicular, prelaryngeal, and also pretracheal.
But first of all, let’s answer two questions. What is a lymph node exactly and what is the role of lymph nodes in the human body?
Now, a lymph node is an oval-shaped organ of the lymphatic system. It’s distributed widely throughout the body, including the neck, armpit, and stomach, and linked by these lymphatic vessels that you see here.
Now, lymph nodes are found all through the body, and lymph nodes are important for the immune system to function properly. They do so by acting as filters for foreign particles and also cancer cells.
So now that we have that definition down, we’re going to move on and talk about, now, the list of lymph nodes of the neck that can be classified into three specific chains. One is known as the upper horizontal chain of nodes. There is also a lateral cervical and an anterior cervical node.
Note that we will discuss only those that are significant and relevant for the neck region.
Let’s start off, then, with the first one, the upper horizontal chain of nodes, which include the submental and submandibular.
Now, if we highlight here the… as you can see, these are the submental lymph nodes. They lie over the mylohyoid muscle and in the submental triangle.
Now, the afferents come from the chin, lower lip, and mouth structures while the efferents go to, then, the submandibular nodes and internal jugular chain.
And the question is, what is afferent, what is efferent here, when we talk about lymph nodes?
The lymph vessels that carry to the lymph node are called, then, afferent lymph vessel, and those that carry it from the lymph node is, then, called the efferent lymph vessel.
And you can see this image here with a lot more structures, including the mylohyoid muscle.
Now, the next ones that we’re going to be talking about are these, this collection which is known as the submandibular lymph nodes.
Now, they lie in the submandibular triangle in relation to the submandibular gland and facial artery.
Now, in terms of afferent vessels, they come from, then, the lips, cheeks, nose, mouth structures, and salivary glands.
Now, the efferents go to, then, the internal jugular chain.
Now, the second one that we saw on that list, this is the lateral cervical nodes that we’re going to be talking about, and these can be divided into a superficial group and also a deep group, which includes the internal jugular chain and also the supraclavicular chain.
Now, let’s start off with these that you see highlighted in green, which are known as the superficial cervical lymph nodes.
Now, this group lies along the external jugular vein, as you can see here. So this is the external jugular vein, and it will be draining into the internal jugular and transverse cervical nodes.
And here’s an image of a little bit more context, a little bit more structures that we just added onto this image to see how they’re placed over them.
We’re going to move on, now, to, again, this list here: the deep group, which consists, then, of the internal jugular lymph nodes, and right now, we’re seeing highlighted what is known to be as the interior and lateral internal jugular lymph nodes.
Now, lymph nodes of the internal jugular chain, they lie anteriorly, as you can clearly see here, laterally, and also posteriorly to the internal jugular vein.
And you can clearly see here the internal jugular veins on this image and how these structures are revolving around this structure or these veins.
Now, they are arbitrarily divided into upper, middle, and lower groups.
Now, the upper group will be draining the oral cavity, the oropharynx, the nasopharynx, the hypopharynx, larynx, and parotid, while the middle group will be draining the hypopharynx, larynx, thyroid, oral cavity, and the oropharynx.
And finally, the lower group will be, then, draining the larynx, thyroid, and cervical esophagus.
Next structures that we’re going to be seeing here, now highlighted in green, these are known as the juguloomohyoid lymph nodes, and they are a part of the deep cervical lymph nodes (or the upper group), and these nodes drain the tongue.
The next ones that we’re going to be highlighting here are part of the deep group, and these are the supraclavicular chain or the supraclavicular lymph nodes, as you can see here.
Now, this chain of lymph nodes lies horizontally along the transverse cervical vessels.
And afferents to those nodes come from the breast, lung, stomach, colon, ovary, and testis.
And as a reminder, afferents are lymph vessels that carry lymph to a lymph node.
We’re going to, now, look at another set of lymph nodes which are known as the anterior cervical nodes or juxta-visceral chain, which include the prelaryngeal and also the pretracheal.
Starting off with the first one that you see here, highlighted in green, these are known as the prelaryngeal lymph nodes.
Now, these are also called Delfian nodes and lie on the cricothyroid membrane. They will be draining the subglottic region of the larynx and the piriform sinuses.
Let me add a few more structures here so you can see how the prelaryngeal lymph nodes or where they’re located more or less in comparison to other structures in this area of the neck.
Now, we’re moving on to the next ones that you see here, highlighted in green. These are known as the pretracheal lymph nodes, and these lie in front of the trachea. They drain the thyroid gland and the trachea.
Now, efferents from these will go, then, to the paratracheal, lower internal jugular, and anterior mediastinal nodes.