The Neck anatomy Is divided into several parts: spinal cord, cervical spine, neck muscles, neck arteries, neck veins, lymph nodes, pharynx, larynx, trachea and thyroid gland.
One of the main functions of the neck is to support the weight of the head, in turn separates it from the torso. It has a flexible structure that allows to move the head in different directions.
From a frontal view of the neck, the laryngeal prominence of the thyroid cartilage, known as an apple or Adam's apple, may be noted. Below this is the cricoid cartilage.
Between the Adam's apple and the chin, the hyoid bone is located. On the other hand, between the cricoid cartilage and the sternal hairpin, are the trachea and the thyroid gland.
The neck has an area called quadrangular, which is limited superiorly by the lower border of the mandible and the mastoid process. On the inside, it is limited by the clavicle and the trapezius muscle.
The cervical spine is also located in the neck. This is composed of 7 cervical vertebrae that give a forward curvature called cervical lordosis.
Between the main arteries and veins of the neck, the common carotids and the external and internal jugular, respectively, can be mentioned.
Definition
The neck is an area of the human body located between the skull, which is above it, and the trunk, located below.
It is the body space where the larynx , the windpipe and the esophagus . At the same time, that's where the thyroid and parathyroid glands are located. The neck has thirty percent of all lymph nodes in the human body.
Anatomy: Neck quadrangular area
The quadrangular area of the neck can be viewed from the side. This space is subdivided by the sternocleidomastoid muscle, from which an anterior cervical triangle and a posterior cervical triangle can be distinguished.
Anterior cervical triangle
This triangle is located at the front of the neck. It is delimited by the anterior midline, the mandible (the maxilla) and the anterolateral sternocleidomastoid muscle.
In the anterior cervical triangle can be lymph nodes. Numerous cranial nerves pass through this part of the neck. The common carotid artery may also be located, which bifurcates into the external and internal carotid arteries. Here you can also find the internal jugular vein, which is responsible for draining the blood from head to neck.
The anterior cervical triangle is subdivided into four smaller triangles, by the digastric muscle and the inferior omohyoid.
Submandibular triangle
It is delimited by the mandible and the digastric muscle. In this triangle is the submandibular salivary gland, the hypoglossal nerve, the mylohyoid muscle and the facial artery.
The carotid triangle
Delimited by the sternocleidomastoid muscle, the back of the digastric muscle and the upper fraction of the omohyoid muscle. In the carotid triangle are the carotid arteries, the internal jugular vein and the vagus nerve.
The muscle triangle or omotraqueal triangle
The region of this triangle is delimited by the midline, the hyoid bone, the upper part of the omohyoid muscle and the sternocleidomastoid muscle. In it you can find the thyroid glands and the parathyroids. In this region of the neck is also located the pharynx.
The submental depression
It is located under the chin or pear. Delimited by the mandible, hyoid and the anterior part of the digastric muscle.
Posterior cervical triangle
This triangle of the neck is delimited by the clavicle, the anterosuperior sternocleidomastoid muscle and the posterior trapezius muscle. The posterior cervical triangle is divided by the omohyoid muscle into an upper occipital triangle and a lower subclavian triangle.
Occipital triangle
This triangle is delimited in the anterior part by the sternocleidomastoid muscle; In the back by the trapezoid; And at the bottom by the omohyoid muscle.
In the occipital triangle are the accessory, supraclavicular nerves and the superior brachial plexus.
Subclavian Triangle
This triangle is smaller than the occipital. It is delimited at the top by the lower fraction of the omohyoid muscle; In its posterior part by the clavicle; And in the anterior part by the sternocleidomastoid muscle.
In the subclavian triangle are the supraclavicular nerves, the subclavian vessels, the brachial plexus and the transverse suprascapular cervical vessels. Also found in it are the external jugular vein and the nerves of the subclavian muscle.
Composition of the cervical spine
The cervical spine is composed of seven cervical vertebrae, which are classified as C1 to C7. This portion of the spine has a slight forward curvature, called cervical lordosis. The C1 vertebra is also called Atlas because it leads to the head, considered the world.
The Atlas has two upper portions that articulate with the occipital bone of the skull. Providing fifty percent of the flexion and extension of the neck.
The C2 vertebra is also called Axis or Axis. It has a joint that connects it with the vertebra C1, being responsible for fifty percent of the rotation of the neck.
All the vertebrae have a hole in their middle part, through which the vertebral artery and the spinal cord , Which travels through the spinal canal 17 mm in diameter, formed by the vertebral arches.
Muscles
The neck is a part of the human body where the presence of different muscles predominates, which fulfill different and specific functions that depend and are related to the place where they are located.
The muscles are located immediately ahead and behind the spine, which are: vertebral vertebrae pre-vertebral and post-vertebral.
Among the anterior vertebral muscles may be Colli muscle and Capitis muscles. These are the ones in charge of the movement of reincorporating the head to its original position, after being leaned back. They can also be flexed or turned sideways.
On the sides of the spine are the lateral cervical muscles. In this zone, the platysma muscle is also located.
The lateral cervical muscles include anterior scalene, medial scalenus, and posterior scalenus. These muscles are located between the second and seventh cervical vertebrae, being responsible for the elevation of the first and second rib at the moment of inspiration. They also allow flexibility of the spine to the sides.
The muscles of the anterior neck, ie the anterior cervical muscles are composed of the suprahyoid muscles, the infrahyoid muscles and the anterior vertebral muscles.
These muscles are accompanied by the digastric, stylohyoid, molohyoid, geniohyoid, sternohyoid and omohyoid.
The sternocleidomastoid muscle is prominent on the side of the neck. It has its origin in the sternum and the clavicle. It is inserted in the lateral surface of the mastoid process by a strong tendon and by an aponeurosis in the superior nuchal line.
This muscle is supplied by the accessory nerve and the cervical nerves. Together with the sternoclavicular muscles, it is responsible for the flexion of the cervical part of the spine.
The trapezius has its origin in the spinous processes of the vertebrae. It is innervated by the accessory spinal nerve and the branches of the third and fourth cervical vertebrae.
Main arteries and veins
The main arteries present in the neck are common carotid arteries. Which are located one on each side (right and left) of the trachea. Organ present in the neck.
They ascend in the neck dividing into two branches at the level of the upper border of the thyroid cartilage. These bifurcations cause them to be called the external and internal carotid artery.
The first one supplies the outside of the head, face and neck. For its part, the internal carotid artery supplies the cranial contents.
The external carotid artery, at the level of the mandible, is divided into small branches called upper thyroid, lingual, facial, occipital, posterior auricular, pharyngeal ascending, temporal superficial and maxillary.
The internal carotid artery begins at the bifurcation of the common carotid, at the level of the upper border of the thyroid cartilage. It is located behind the sternocleidomastoid muscle and lateral to the external carotid artery. This internal artery, unlike the external carotid artery, does not branch.
The main veins of the neck are the external jugular vein and the internal jugular vein. Being the ones in charge of returning the blood of the head and the face.
The external jugular vein receives blood from the outside of the skull and the deep parts of the face. It is formed by the posterior division of the retromandibular vein when it is united with the posterior auricular vein.
The internal jugular vein accumulates blood from the brain , From the superficial parts of the face and from the neck. It is located on the side of the neck, in a vertical direction and in a lateral direction to the internal carotid artery. It is attached to the subclavian vein at the root of the neck, and there forms the brachiocephalic vein.
References
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