The retropharyngeal space (abbreviated as "RPS") is a

potential space In anatomy, a potential space is a space between two adjacent structures that are normally pressed together (directly apposed). Many anatomic spaces are potential spaces, which means that they are potential rather than realized (with their realiz ...

and deep compartment of the head and neck situated posterior to the

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struc ...

. The RPS is bounded anteriorly by the

buccopharyngeal fascia The buccopharyngeal fascia is a fascia in the head and neck. Structure The buccopharyngeal runs parallel to the medial aspect of the carotid sheath. It is a thin lamina given off from the pretracheal fascia. It is attached to the prevertebral f ...

, posteriorly by the

alar fascia The alar fascia is a layer of fascia, sometimes described as part of the prevertebral fascia, and sometimes as in front of it. Anatomy Cranially, it reaches the skull, and caudally, it reaches the second thoracic vertebra. In 2015, the anatomy ...

, and laterally by the

carotid sheath The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adip ...

. It spans from the base of the skull superiorly to the mediastinum inferiorly. It contains the

retropharyngeal lymph nodes The retropharyngeal lymph nodes, from one to three in number, lie in the buccopharyngeal fascia, behind the upper part of the pharynx and in front of the arch of the atlas, being separated, however, from the latter by the Longus capitis. Their ' ...

. Sources consider the retropharyngeal space to be in principle subdivided into the so-called "true retropharyngeal space" or "retropharyngeal space proper" (part of the RSP situated anterior to the alar fascia), and the

danger space The danger space or alar space, is a region of the neck. The common name originates from the risk that an infection in this space can spread directly to the thorax, and, due to being a space continuous on the left and right, can furthermore allow i ...

(part of the RSP situated posterior to the alar fascia). The danger space is sometimes also lumped together with the true RPS and the whole referred to as the RPS because the alar fascia is an ineffective barrier. Infections from the head and neck can spread down through the danger space into the

posterior mediastinum The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...

Anatomy

Superiorly, the retropharingeal space terminates at the base of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

(more specifically, at the clivus). Inferiorly, the true RPS terminates at a variable level along the upper thoracic spine with the fusion of alar fascia and visceral fascia; sources either give the inferior termination of the true RPS as occurring at approximately the vertebral level of T4 or at a variable level anywhere between the T1-T6. The

component of the RPS meanwhile extends further inferior-ward, entering the posterior mediastinum to reach the level of the diaphragm.

The retropharnygeal space contains the

. The suprahyoid portion of the RPS contains the lymph nodes as well as adipose tissue, while the infrahyoid portion contains adipose tissue only. A midline raphe is sometimes present in the RPS, subdividing it into a left half and a right half.

Anatomical relations

Positions of adjacent anatomical structures in relation to the retropharyngeal space are as follows: * Superior:

Base of the skull The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria. Structure Structures found at the base of the skull are for ...

* Inferior:

Posterior mediastinum The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...

* Lateral:

Carotid sheath The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adip ...

* Anterior:

Buccopharyngeal fascia The buccopharyngeal fascia is a fascia in the head and neck. Structure The buccopharyngeal runs parallel to the medial aspect of the carotid sheath. It is a thin lamina given off from the pretracheal fascia. It is attached to the prevertebral f ...

* Posterior:

Prevertebral fascia The prevertebral fascia (or prevertebral layer of cervical fascia) is a fascia in the neck. Variations In some literature, the prevertebral fascia also includes the other fascial layers extending around the vertebral column and enclosing all musc ...

(

true RPS)

Clinical significance

A midline raphe may be present in this the RPS, making some infections appear unilateral. However without treatment infections can easily spread from one space to the adjacent space. If more than half of the size of the C2 vertebra, it may indicate

retropharyngeal abscess Retropharyngeal abscess (RPA) is an abscess located in the tissues in the back of the throat behind the posterior pharyngeal wall (the retropharyngeal space). Because RPAs typically occur in deep tissue, they are difficult to diagnose by physical ...

Additional images

File:Retroabscess10.JPG,

Retropharyngeal abscess Retropharyngeal abscess (RPA) is an abscess located in the tissues in the back of the throat behind the posterior pharyngeal wall (the retropharyngeal space). Because RPAs typically occur in deep tissue, they are difficult to diagnose by physical ...

References

External links

* * Fascial spaces of the head and neck {{anatomy-stub