iPedia Free Information Center

Information about Mediastinum

Mediastinum. The division between superior and inferior is at the sternal angle.
Mediastinum anatomy
subject #239 1090
Dorlands/Elsevier m_06/12518945
The mediastinum is a non-delineated group of structures in the thorax (chest), surrounded by loose connective tissue. It is the central compartment of the thoracic cavity. It contains the heart, the great vessels of the heart, esophagus, trachea, thymus, and lymph nodes of the central chest.

Anatomy

The mediastinum lies between the right and left pleuræ in and near the median sagittal plane of the chest. It extends from the sternum in front to the vertebral column behind, and contains all the thoracic viscera except the lungs. It may be divided for purposes of description into two parts:
  • an upper portion, above the upper level of the pericardium, which is named the superior mediastinum;
  • and a lower portion, below the upper level of the pericardium. This lower portion is again subdivided into three parts, viz.:
  • that in front of the pericardium, the anterior mediastinum;
  • that containing the pericardium and its contents, the middle mediastinum;
  • and that behind the pericardium, the posterior mediastinum.
It is surrounded by the chest wall anteriorly, the lungs laterally and the spine posteriorly. It is continuous with the loose connective tissue of the neck, and extends inferiorly onto the diaphragm.

Note that clinical radiologists and anatomists categorize the mediastinum in slightly different ways.

Role in disease

Main article: mediastinal tumor


The mediastinum frequently is the site of involvement of various tumors.

Mediastinitis is inflammation of the tissues in the mediastinum, usually bacterial and due to rupture of organs in the mediastinum. As the infection can progress very quickly, this is a serious condition.

Pneumomediastinum is the presence of air in the mediastinum, which can lead to pneumothorax, pneumoperitoneum, and pneumopericardium if left untreated in some cases. However, that does not always happen and sometimes those conditions actually are the cause, not the result, of pneumomediastinum.

These two conditions frequently accompany Boerhaave's syndrome, or spontaneous esophageal rupture.

See also

External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
 •  • [ e]
General anatomy of torso
ThoraxMediastinum (Superior, Anterior, Middle, Posterior) • Superior thoracic aperture • Inferior thoracic aperture • Triangle of auscultation • Intercostal space • Thoracic plane • Thoracic cavity • Thoracic cage
Thoracic diaphragmopenings (Caval opening, Esophageal hiatus, Aortic hiatus, Foramina of Morgagni) • Central tendon • Crus of diaphragm • arcuate ligaments (Lateral, Medial, Median)
AbdomenMcBurney's point • Lumbar triangle • Arcuate line • Linea alba
PerineumUrogenital triangle • Anal triangle • Superficial perineal pouch • Perineal membrane • Deep perineal pouch • Urogenital diaphragm • Superior fascia of the urogenital diaphragm • Ischiorectal fossa - Pudendal canal
FasciaPectoral fascia - Clavipectoral fascia - Transversalis fascia - Deep inguinal ring - Superficial inguinal ring - Fascia of Camper - Fascia of Scarpa - Fascia of Colles
The sternal angle is the angle formed by the junction of the manubrium and the body of the sternum in the form of a secondary cartilaginous joint (symphysis). This is also called the manubriosternal joint or Angle of Louis. The sternal angle is a palpable clinical landmark.
..... Click the link for more information.
Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
..... Click the link for more information.
thorax is a division of an animal's body that lies between the head and the abdomen.

In mammals, the thorax is the region of the body formed by the sternum, the thoracic vertebrae and the ribs. It extends from the neck to the diaphragm, not including the upper limbs.
..... Click the link for more information.
Areolar connective tissue (or loose connective tissue) is the most widely distributed connective tissue type in vertebrates.

Location

It can be found in the skin as well as in places that connect epithelium to other tissues.
..... Click the link for more information.
The thoracic cavity (or chest cavity) is the chamber of the human body (and other animal bodies) that is protected by the thoracic wall (thoracic cage and associated skin, muscle, and fascia).
..... Click the link for more information.
heart is a muscular organ responsible for pumping blood through the blood vessels by repeated, rhythmic contractions, or a similar structure in the annelids, mollusks, and arthropods.
..... Click the link for more information.
The esophagus (also spelled oesophagus/œsophagus, Greek οἰσοφάγος), or gullet
..... Click the link for more information.
Trachea is a common biological term for an airway through which respiratory air transport takes place in organisms.
  • Vertebrate trachea, in terrestrial vertebrates, such as birds and mammals, the trachea allows oxygen and carbon dioxide to move from the throat to the lungs

..... Click the link for more information.
thymus is an organ located in the upper anterior portion of the chest cavity just behind the sternum. Hormones produced by this organ stimulate the production of certain infection-fighting cells. It is of central importance in the maturation of T cells.
..... Click the link for more information.
Lymph nodes are components of the lymphatic system. They are sometimes informally called lymph glands but, as they do not secrete substances, such terminology is not entirely accurate. They are found mostly in the neck area.
..... Click the link for more information.
pleurae. The outer pleura is attached to the chest wall and is known as the parietal pleura; the inner one is attached to the lung and other visceral tissues and is known as the visceral pleura.
..... Click the link for more information.
In sciences dealing with the anatomy of animals, precise anatomical terms of location are necessary for a variety of reasons. Non-scientists often wonder why zoological and human anatomists use complex terminology to describe locations on a body, when common terms like "up",
..... Click the link for more information.
lungs flank the heart and great vessels in the chest cavity.[1]]]

The lung is the essential respiration organ in air-breathing vertebrates, the most primitive being the lungfish.
..... Click the link for more information.
The superior mediastinum is that portion of the interpleural space which lies between the manubrium sterni in front, and the upper thoracic vertebrae behind.

Boundaries

It is bounded:
  • below

..... Click the link for more information.
The anterior mediastinum exists only on the left side where the left pleura diverges from the mid-sternal line.

It is narrow, above, but widens out a little below.

Boundaries

It is bounded:
  • in front by the sternum
  • laterally

..... Click the link for more information.
The middle mediastinum is the broadest part of the interpleural space.

Contents

It contains:
  • the heart enclosed in the pericardium
  • the ascending aorta
  • the lower half of the superior vena cava with the azygos vein opening into it

..... Click the link for more information.
The posterior mediastinum is an irregular triangular space running parallel with the vertebral column.

Boundaries

It is bounded:
  • anteriorally by the pericardium (in front of)
  • inferiorally by the thoracic surface of the diaphragm (below).

..... Click the link for more information.
The neck is the part of the body on many limbed vertebrates that distinguishes the head from the torso or trunk.

Anatomy of the human neck

Bony anatomy: The cervical spine

The cervical portion of the human spine
..... Click the link for more information.
diaphragm is a sheet of muscle extending across the bottom of the ribcage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in respiration.
..... Click the link for more information.
The introduction to this article provides insufficient context for those unfamiliar with the subject matter.
Please help [ improve the introduction] to meet Wikipedia's layout standards.

..... Click the link for more information.
The introduction to this article provides insufficient context for those unfamiliar with the subject matter.
Please help [ improve the introduction] to meet Wikipedia's layout standards.

..... Click the link for more information.
Mediastinitis
Classification & external resources

ICD-10 J 98.5
ICD-9 519.2

DiseasesDB 7909
MedlinePlus 000081
eMedicine med/2798  
MeSH D008480 Mediastinitis is inflammation of the tissues in the mid-chest, or mediastinum.
..... Click the link for more information.
Inflammation (Latin, inflammatio, to set on fire) is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants.
..... Click the link for more information.
Bacteria

Phyla

Actinobacteria
Aquificae
Chlamydiae
Bacteroidetes/Chlorobi
Chloroflexi
Chrysiogenetes
Cyanobacteria
Deferribacteres
Deinococcus-Thermus
Dictyoglomi
Fibrobacteres/Acidobacteria
Firmicutes
Fusobacteria
..... Click the link for more information.
MeSH D008478

Pneumomediastinum (or mediastinal emphysema, from Greek pneuma - "air") is a condition in which air is present in the mediastinum. It was first described in 1819 by René Laennec.
..... Click the link for more information.
Pneumothorax
Classification & external resources

Chest X-ray of Left-sided Tension Pneumothorax
ICD-10 J 93. , S 27.0
ICD-9 512 , 860

DiseasesDB 10195
MedlinePlus 000087
eMedicine emerg/469  
MeSH D011030
..... Click the link for more information.
pneumoperitoneum.
ICD-10 K 66.8
ICD-9 568.89 , 770.2

DiseasesDB 31511

eMedicine radio/562  
MeSH D011027

Description

Pneumoperitoneum is air or gas in the abdominal (peritoneal) cavity[1]
..... Click the link for more information.
MeSH D004939 Boerhaave syndrome (also called Boerhaave's syndrome) is rupture of the esophagus. It is generally caused by excessive vomiting in eating disorders such as bulimia although it may rarely occur in extremely forceful coughing or other situations.
..... Click the link for more information.
Esophageal can refer to:
  • The esophagus
  • Esophageal arteries

..... Click the link for more information.
Widened mediastinum' is a mediastinum with a measured width greater than 8 cm on PA chest X-ray.

Associated conditions

A widened mediastinum can be indicative of several important pathologies, such as aortic aneurysm and hilar lymphadenopathy.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter