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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 of the alar fascia was revisited using dissection in conjunction with E12 plastination. The authors revealed that the alar fascia originated as a well defined midline structure at the level of C1 and does not reach the base of the skull. It is suggested that the area between C1 and the base of the skull is a potential entry into the danger space. Anatomical relations The alar fascia represents the posterior boundary of the retropharyngeal space The retropharyngeal space (abbreviated as "RPS") is a potential space and deep compartment of the head and neck situated posterior to the pharynx. The RPS is bounded anteriorly by the buccopharyngeal fascia, posteriorly by the alar fascia, and la .... See also * Retrovisceral space Referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 muscles laterally and posteriorly to it. However, in this article, it is assumed to be as marked in the corresponding picture. Location The prevertebral fascia extends medially behind the carotid vessels, where it assists in forming their sheath, and passes in front of the prevertebral muscles. The prevertebral fascia is fixed above to the base of the skull, and below it extends behind the esophagus into the posterior mediastinal cavity of the thorax. It descends in front of the longus colli muscles. The prevertebral fascia is prolonged downward and laterally behind the carotid vessels and in front of the scalene muscles. It forms a sheath for the brachial nerves, subclavian artery, and subclavian vein in the posterior triangle of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thoracic Vertebra
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae, with the lower ones being much larger than the upper. They are distinguished by the presence of facets on the sides of the bodies for articulation with the heads of the ribs, as well as facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercles of the ribs. By convention, the human thoracic vertebrae are numbered T1–T12, with the first one (T1) located closest to the skull and the others going down the spine toward the lumbar region. General characteristics These are the general characteristics of the second through eighth thoracic vertebrae. The first and ninth through twelfth vertebrae contain certain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastination
Plastination is a technique or process used in anatomy to preserve bodies or body parts, first developed by Gunther von Hagens in 1977. The water and fat are replaced by certain plastics, yielding specimens that can be touched, do not smell or decay, and even retain most properties of the original sample. Process Four steps are used in the standard process of plastination: fixation, dehydration, forced impregnation in a vacuum, and hardening. Water and lipid tissues are replaced by curable polymers, which include silicone, epoxy, and polyester-copolymer. The first step of plastination, fixation, frequently uses a formaldehyde-based solution, and serves two functions. Dissecting the specimen to show specific anatomical elements can be time-consuming. Formaldehyde or other preserving solutions help prevent decomposition of the tissues. They may also confer a degree of rigidity. This can be beneficial in maintaining the shape or arrangement of a specimen. A stomach might be inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 infection to spread easily to either side. Structure It is bounded at the top by the skull base, at the front by the alar fascia and behind by the prevertebral fascia. It comes to an end at the level of the diaphragm. The retropharyngeal space is found anterior to the danger space, between the alar fascia and buccopharyngeal fascia. There exists a midline raphe in this space so some infections of this space appear unilateral. Clinical significance On CT or MRI it is only visible when distended by fluid or pus, below the level of T1-T6, as the retropharyngeal space ends at this level, allowing distinction between the two entities. Superior spread of infection can affect the contents of the carotid sheath, including the internal jugular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retropharyngeal Space
The retropharyngeal space (abbreviated as "RPS") is a potential space and deep compartment of the head and neck situated posterior to the pharynx. The RPS is bounded anteriorly by the buccopharyngeal fascia, posteriorly by the alar fascia, and laterally by the carotid sheath. It spans from the base of the skull superiorly to the mediastinum inferiorly. It contains the retropharyngeal lymph nodes. 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 (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. Anatomy Superiorly, the retropharingeal sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrovisceral Space
The retrovisceral space is divided into the retropharyngeal space and the danger space 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 .... It is of particular clinical importance because it is a main route by which oropharyngeal infections can spread into the mediastinum. Some sources say the retrovisceral space is the same as the retropharyngeal space. Other sources say that the retrovisceral space is "continuous superiorly" with the retropharyngeal space. References External links Thoracoscopic drainage with wound edge protector for descending necrotizing mediastinitis* http://iris3.med.tufts.edu/headneck/spaces.htm Human head and neck {{anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
