The neck is the region of the body that connects the head to the thorax.
Focus on the anatomy of the neck, it’s functioning, and the different related pathologies and how to treat them.
Anatomy of the neck
The neck is bounded forward by the throat, back by the nape of the neck, down by the collarbones, and up by the mandible.
At the throat, the neck is crossed by the upper parts of the digestive system, the pharynx, and the esophagus, and by the upper parts of the respiratory system, the larynx, and the trachea.
There are also the following glands:
- The thyroid, located on the anterior surface of the trachea, secretes two thyroid hormones that act on metabolism;
- parathyroids are small glands located on the posterior surface of the thyroid, they secrete a hormone acting on the level of calcium in the blood;
- the salivary glands which are represented by the parotid (located in front of the ears) and the submandibular (located under the jaw);
- the platysma muscle covers the front of the neck and allows movements of the mouth and tension of the skin of the neck;
- The sternocleidomastoid muscle is stretched on the sides of the neck between the sternum, clavicle, and temporal bone and allows flexion, tilt, and head rotation.
Back, the nape consists of the seven cervical vertebrae of the spine, numbered from C1 to C7. These cervicals provide strength and mobility to the neck:
- The first two vertebrae, called atlas (C1) and axis (C2), have a different morphology from the other vertebrae which gives them an important role in the mobility of the neck;
- The atlas articulates with the occipital bone of the head, which allows us to tilt the head as a sign of assent;
- the axis (C2) has a pivot function that allows the rotation of the atlas, and therefore of the head;
- the articulation between C1 and C2 allows the rotation of the lateral head as a sign of denial.
Many muscles cover the neck, they are attached to the skull, cervical vertebrae, and clavicles. They allow the mobility of the head and are mostly strap-shaped. We find:
- the sternocleidomastoid muscle: located between the collarbone and the base of the ear;
- the trapezius muscle: is diamond-shaped that covers the posterior part of the neck, shoulder, and upper back;
- the mastoid: located under the skull at the base of the ear which serves as a hook for the top of the sternocleidomastoid muscle;
- the mandible: constitutes the bone of the chin;
- the hyoid bone: located in the anterior part of the neck;
- Clavicles: located on the top of the shoulders, at the base of the neck.
Vascularization and nervous elements
The neck is crossed on each side by a common carotid artery that divides into external and internal carotids, a vertebral artery, and by two jugular veins (internal and external).
Many nerves run through the neck, including the vagus (or pneumogastric nerve, which role in digestion and heart rate), phrenic (innervation of the diaphragm), and spinal (mobility and sensitivity of the limbs).
Physiology of the neck
The main role of the neck is the support and mobility of the head thanks to its bone and muscle structure.
Because of all the structures, it contains, the neck also has an important role in digestion, breathing, phonation, and metabolism.
Pathologies of the neck
Muscle tension and stiffness
Neck tension and stiffness are prolonged muscle contractions in the shoulders and neck that can become painful. They usually follow the maintenance of a position for several hours or have poor posture.
Whiplash is also called whiplash (movement of the head forward, then backward). It can occur at the time of a car accident or a strong impact during the practice of a sport.
Torticollis is an involuntary muscle contraction of one of the neck muscles. This contraction results in severe pain in the neck and blocked movements. The person is as if “stuck”.
Cervical osteoarthritis is a wear of cartilage that is located at the joints of the cervical vertebrae. This pathology mainly concerns people over 50 years of age and causes pain, headaches, and stiffness of the neck. It is a chronic disease that evolves gradually over several years.
A herniated disc is the protrusion of a portion of an intervertebral disc. These discs give flexibility to the column and serve as shock absorbers in case of impact.
A herniated disc occurs when a disc weakens, cracks, or ruptures and part of the gelatinous nucleus erupts. It can affect any area of the spine. In the case of the neck, it is called a cervical disc herniation.
There are different types of neck inflammations, here are the most common.
Angina is an infection in the throat, specifically the tonsils. It can extend to the entire pharynx. Angina is due either to a virus, the most common case, or bacteria and is characterized by a significant sore throat.
Laryngitis is an inflammation of the larynx, especially in the vocal cords. Talking then becomes painful.
There are two types of laryngitis: acute laryngitis and chronic laryngitis and there are differences between childhood and adult laryngitis.
Pharyngitis is an inflammation of the pharynx, most often due to a mild infection, caused by a virus or bacteria. When the inflammation also affects the nasal mucous membranes, it is called nasopharyngitis.
A cyst is a cavity that contains a fluid or semi-solid substance that forms in an organ or tissue. The vast majority of cysts are not cancerous.
In the neck, the most common is the cyst of the thyroglossal tract (nearly 70% of congenital anomalies in this area). Embryonic in origin, this type of cyst is the consequence of abnormal thyroid development during the first weeks of pregnancy.
In 50% of cases, the cyst of the thyroglossal tract manifests itself before the age of 20. Infection is usually its main complication.
Lymphadenopathy (lymph nodes)
Most often, it is a lymph node that swells in response to an infection, such as a simple cold for example. However, there are many other possible causes of “swelling” in the neck or throat. Consult your doctor in the slightest doubt to determine the origin.
Pathologies of the thyroid gland
Goiter refers to an increase in the volume of the thyroid gland. It is common, especially in women.
Goiter is not a disease, but it can be present in a wide variety of diseases.
It is not uncommon for a small mass to form in the thyroid gland, for reasons that are still often unknown. It is called a thyroid nodule.
Thyroid cancer is a relatively rare cancer.
Thyroid cancer affects women at 75%. This cancer is usually detected at an early stage. The treatment is then very effective with a cure in 90% of cases.
Hypothyroidism is the consequence of insufficient hormone production by the thyroid gland. The people most affected by this condition are women after the age of 50.
In people with hyperthyroidism, their metabolism works in an accelerated manner. They may feel nervous, have frequent bowel movements, tremble and lose weight, for example.
Neck treatments and prevention
Neck pain affects 10 to 20% of the adult population. To relieve and prevent these problems, it is possible to indulge in some daily exercises that can quickly become habits.
For some conditions, such as laryngitis, certain recommendations can prevent you from getting sick. For others, a diet rich in iodine will avoid deficiency, which is a risk factor for thyroid nodules for example.
On the other hand, for other pathologies such as thyroid cancer or goiter, there is no means of prevention.
Cervical ultrasound is a medical imaging technique based on the use of ultrasound, and inaudible sound waves, which make it possible to “visualize” the inside of the body.
It is an examination that confirms the presence, for example, of a cyst or thyroid cancer (measurement of the gland, presence of nodules).
CT is a diagnostic imaging technique that involves “scanning” a given area of the body to create cross-sectional images using an X-ray beam.
The term “scanner” is actually the name of the medical device, but it is commonly used to name the exam. This is also called a CT scan or CT scan.
The CT scan can also be used to determine the size of a cyst or the presence of a tumor for example.
Magnetic resonance imaging is a diagnostic medical examination performed using a large cylindrical device in which a magnetic field and radio waves are produced to generate very precise images, in 2D or 3D, of the parts of the body (here the neck and its internal parts).
MRI provides detailed images of the cervical spine, nerves, and nearby tissues. It can be used to diagnose trauma to the spine, cervical hernia, or tumor of the spine for example.
A laryngoscopy is a doctor’s examination of the back of the throat, larynx, and vocal cords using an endoscope (a thin, tube-like instrument with a light source and lens).
This procedure is performed to investigate, for example, the causes of throat pain, bleeding, or diagnosing cancer.
An exploratory cervicotomy is a surgical procedure that involves opening the neck to remove a cyst or lymph node whose nature is not known or to seek a diagnosis.
Thyroid-stimulating hormone (TSH) testing
TSH testing is the best indicator for assessing thyroid disease. It allows diagnosing hypo or hyperthyroidism, to monitor thyroid pathology that is performed in people with goiter.
Parathyroid hormone (PTH) testing
The parathyroid hormone (secreted by the parathyroid glands) plays a major role in regulating calcium in the body. A dosage is recommended in case of hypercalcemia (too high a level of calcium in the blood or kidney stones for example).
The “giraffe boy” is nicknamed a 15-year-old Chinese boy who has the longest shot in the world with 10 cervical vertebrae instead of 7. This is the consequence of a malformation that causes the boy pain and difficulty walking (compression of the nerves of the neck).
The giraffe, with its long neck, is the tallest land mammal. Growing up to 5.30 m for males and 4.30 m for females, a giraffe has the same number of cervical vertebrae as mammals, i.e. 7, which measure about 40 cm each.
Image Credit: Photo by Karolina Grabowska from pexels.com