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Encyclopedia > Diaphragm (anatomy)
Diaphragm
Posterior surface of sternum and costal cartilages, showing Transversus thoracis.
Under surface of the human diaphragm
Latin diaphragma
Gray's subject #117 404
System {{{System}}}
Precursor septum transversum
MeSH A02.633.567.900.300
Dorlands/Elsevier d_15/12293509

In the anatomy of mammals, the diaphragm is a shelf of muscle extending across the bottom of the ribcage. The diaphragm separates the thoracic cavity (with lung and heart) from the abdominal cavity (with liver, stomach, intestines, etc.). In its relaxed state, the diaphragm is shaped like a dome. Image File history File links Download high resolution version (391x626, 89 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Diaphragm (anatomy) Wikipedia:Grays Anatomy images with missing articles 8 Transversus thoracis muscle List of images in... The costal cartilages are bars of hyaline cartilage which serve to prolong the ribs forward and contribute very materially to the elasticity of the walls of the thorax. ... The tranversus thoracis lies internal to the thoracic cage, anteriorly. ... Image File history File links Diaphragm. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... Embryology is the branch of developmental biology that studies embryos and their development. ... The liver arises in the form of a diverticulum or hollow outgrowth from the ventral surface of that portion of the gut which afterward becomes the descending part of the duodenum. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo Elsevier, the worlds largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. ... Anatomical drawing of the human muscles from the Encyclopédie. ... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (includes extinct ancestors)/Placentalia (excludes extinct ancestors) Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla... A top-down view of skeletal muscle Muscle is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... This article is about the bones called ribs. ... The thoracic cavity is the chamber of the human body (and other animal bodies) that is enclosed by the ribcage and the diaphragm. ... The lungs flank the heart and great vessels in the chest cavity. ... The heart and lungs, from an older edition of Grays Anatomy. ... The abdominal cavity is the cavity of the human body (and other animal bodies) that holds the bulk of the viscera and which is located below (or posterior to) the thoracic cavity. ... The liver is the largest internal organ of the human body. ... In anatomy, the stomach (in ancient Greek στόμαχος) is an organ in the gastrointestinal tract used to digest food. ... The intestine is the portion of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine. ...

Contents


Function

It is critically important in respiration: in order to draw air into the lungs, the diaphragm contracts, thus enlarging the thoracic cavity and reducing intra-thoracic pressure (the external intercostals muscles also participate in this enlargement). When the diaphragm relaxes, air is exhaled by elastic recoil of the lung and the tissues lining the thoracic cavity. The diaphragm is also found in other vertebrates such as reptiles. It has been suggested that Gas exchange be merged into this article or section. ... Intercostal muscles are several groups of muscles that run between the ribs, and help form and move the chest wall. ... Typical classes Petromyzontidae (lampreys) Placodermi - extinct Chondrichthyes (cartilaginous fish) Acanthodii - extinct Actinopterygii (ray-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Amphibia (amphibians) Reptilia (reptiles) Aves (birds) Mammalia (mammals) Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Orders  Crocodilia - Crocodilians scary crocodiles. ...


The diaphragm also helps to expel vomit, feces, and urine from the body by increasing intra-abdominal pressure. Vomiting (or emesis) is the forceful expulsion of the contents of ones stomach through the mouth. ... Rabbit feces are usually 8-10 mm in diameter, dry to the touch, and look similar to a raisin. ... Urine is liquid waste excreted by the kidneys and is produced by the process of filtration. ...


Pathology

A hiatal hernia can result from a tear or weakness in the diaphragm near the gastroesophageal junction. Hiatus hernia or hiatal hernia is the protrusion (or hernia) of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm. ... The esophagus (also spelled oesophagus/Å“sophagus), or gullet is the muscular tube in vertebrates through which ingested food passes from the mouth area to the stomach. ...


If the diaphragm is struck, or otherwise spasms, breathing will become difficult. This is called having the wind knocked out of you. A spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice. ... Getting the wind knocked out of you occurs when sudden force is applied to the abdomen. ...


The diaphragm is sometimes deemed to consist of left and right hemidiaphragms. The two are visible as separate dome-like structures on chest X-ray. In addition, they are controlled separately by the left and right phrenic nerves; damage to one of these nerves leads to dysfunction or paralysis of the corresponding hemidiaphgram (and damage to both nerves can cause bilateral paralysis, severely impairing respiration). Chest X-ray A chest X-ray is a radiological film obtained by X-ray taken of the thorax which is used to diagnose problems with that area. ... The phrenic nerve arises from the third, fourth, and fifth cervical spinal nerves (C3-C5). ... Paralysis is the complete loss of muscle function for one or more muscle groups. ... Bilateralism is a term referring to trade or political relations between two states. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...


A hiccup occurs when the diaphragm contracts periodically without voluntary control. A hiccup or hiccough (generally pronounced HICK-up (IPA: /ˈhɪ.kəp/) independent of the spelling) is an involuntary spasm of the diaphragm; typically this repeats several times a minute. ...


Anatomy

The Diaphragm is a dome-shaped musculofibrous septum which separates the thoracic from the abdominal cavity, its convex upper surface forming the floor of the former, and its concave under surface the roof of the latter. Its peripheral part consists of muscular fibers which take origin from the circumference of the thoracic outlet and converge to be inserted into a central tendon. The superior thoracic aperture refers to the superior opening of the thoracic cavity. ...


The muscular fibers may be grouped according to their origins into three parts—sternal, costal, and lumbar.

  • The sternal part arises by two fleshy slips from the back of the xiphoid process.
  • the costal part from the inner surfaces of the cartilages and adjacent portions of the lower six ribs on either side, interdigitating with the Transversus abdominis.
  • The lumbar part from aponeurotic arches, named the lumbocostal arches, and from the lumbar vertebræ by two pillars or crura.

There are two lumbocostal arches, a medial and a lateral, on either side. The xyphoid process or xiphoid process is a small cartilaginous extension to the lower part of the sternum which may become ossified in the adult. ... The transversus abdominis muscle, also known as the transverse abdominal muscle, is a muscle layer of the anterior and lateral abdominal wall which is near to the internal oblique muscle. ...

  • The Medial Lumbocostal Arch (arcus lumbocostalis medialis; internal arcuate ligament) is a tendinous arch in the fascia covering the upper part of the Psoas major; medially, it is continuous with the lateral tendinous margin of the corresponding crus, and is attached to the side of the body of the first or second lumbar vertebra; laterally, it is fixed to the front of the transverse process of the first and, sometimes also, to that of the second lumbar vertebra.
  • The Lateral Lumbocostal Arch (arcus lumbocostalis lateralis [Halleri]; external arcuate ligament) arches across the upper part of the Quadratus lumborum, and is attached, medially, to the front of the transverse process of the first lumbar vertebra, and, laterally, to the tip and lower margin of the twelfth rib.

The psoas major is a muscle of the human abdomen. ...

The Crura

At their origins the crura are tendinous in structure, and blend with the anterior longitudinal ligament of the vertebral column. The anterior longitudinal ligament runs down the anterior surface of the spine. ... The vertebral column seen from the side Different regions (curvatures) of the vertebral column The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ...


The right crus, larger and longer than the left, arises from the anterior surfaces of the bodies and intervertebral fibrocartilages of the upper three lumbar vertebræ, while the left crus arises from the corresponding parts of the upper two only. A typical lumbar vertebra The lumbar vertebrae are the largest segments of the movable part of the vertebral column, and can be distinguished by the absence of a foramen (hole) in the transverse process, and by the absence of facets on the sides of the body. ...


The medial tendinous margins of the crura pass forward and medialward, and meet in the middle line to form an arch across the front of the aorta; this arch is often poorly defined.


From this series of origins the fibers of the diaphragm converge to be inserted into the central tendon.


The fibers arising from the xiphoid process are very short, and occasionally aponeurotic; those from the medial and lateral lumbocostal arches, and more especially those from the ribs and their cartilages, are longer, and describe marked curves as they ascend and converge to their insertion. The fibers of the crura diverge as they ascend, the most lateral being directed upward and lateralward to the central tendon.


The medial fibers of the right crus ascend on the left side of the esophageal hiatus, and occasionally a fasciculus of the left crus crosses the aorta and runs obliquely through the fibers of the right crus toward the vena caval foramen.


The Central Tendon

The central tendon of the diaphragm is a thin but strong aponeurosis situated near the center of the vault formed by the muscle, but somewhat closer to the front than to the back of the thorax, so that the posterior muscular fibers are the longer. Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body that lies between the head and the abdomen. ...


It is situated immediately below the pericardium, with which it is partially blended. The pericardium is a double-walled sac that contains the heart and the roots of the great vessels. ...


It is shaped somewhat like a trefoil leaf, consisting of three divisions or leaflets separated from one another by slight indentations.


The right leaflet is the largest, the middle, directed toward the xiphoid process, the next in size, and the left the smallest. The xyphoid process or xiphoid process is a small cartilaginous extension to the lower part of the sternum which may become ossified in the adult. ...


In structure the tendon is composed of several planes of fibers, which intersect one another at various angles and unite into straight or curved bundles—an arrangement which gives it additional strength.


Openings in the Diaphragm

The diaphragm is pierced by a series of apertures to permit of the passage of structures between the thorax and abdomen. Three large openings—the aortic, the esophageal, and the vena caval—and a series of smaller ones are described. The largest artery in the human body, the aorta originates from the left ventricle of the heart and brings oxygenated blood to all parts of the body in the systemic circulation. ... The esophagus, oe/œsophagus*, or gullet is the muscular tube in vertebrates through which ingested food passes from the mouth area to the stomach. ... This article may be too technical for most readers to understand. ...

  • The aortic hiatus (hiatus aorticus) is the lowest and most posterior of the large apertures; it lies at the level of the twelfth thoracic vertebra. Strictly speaking, it is not an aperture in the diaphragm but an osseoaponeurotic opening between it and the vertebral column, and therefore behind the diaphragm; occasionally some tendinous fibers prolonged across the bodies of the vertebræ from the medial parts of the lower ends of the crura pass behind the aorta, and thus convert the hiatus into a fibrous ring. The hiatus is situated slightly to the left of the middle line, and is bounded in front by the crura, and behind by the body of the first lumbar vertebra. Through it pass the aorta, the azygos vein, and the thoracic duct; occasionally the azygos vein is transmitted through the right crus.
  • The esophageal hiatus is situated in the muscular part of the diaphragm at the level of the tenth thoracic vertebra, and is elliptical in shape. It is placed above, in front, and a little to the left of the aortic hiatus, and transmits the esophagus, the vagus nerves, and some small esophageal arteries. The right crus of the diaphragm loops around forming a sling around the diaphragm. Upon inspiration, this sling would constrict the diaphragm, forming an anatomical sphincter that prevents stomach contents from refluxing up the oesophagus when intra-abdominal pressure rises during inspiration.
  • The vena caval foramen is the highest of the three, and is situated about the level of the fibrocartilage between the eighth and ninth thoracic vertebræ. It is quadrilateral in form, and is placed at the junction of the right and middle leaflets of the central tendon, so that its margins are tendinous. By being situated in the tendinous part of the diaphragm, it is stretched open every time inspiration occurs. Since thoracic pressure decreases upon inspiration and draws the caval blood upwards toward the right atrium, increasing the size of the opening allows more blood to return to the heart, maximizing the efficacy of lowered thoracic pressure returning blood to the heart. It transmits the inferior vena cava, the wall of which is adherent to the margins of the opening, and some branches of the right phrenic nerve.

On either side two small intervals exist at which the muscular fibers of the diaphragm are deficient and are replaced by areolar tissue. One between the sternal and costal parts transmits the superior epigastric branch of the internal mammary artery and some lymphatics from the abdominal wall and convex surface of the liver. The other, between the fibers springing from the medial and lateral lumbocostal arches, is less constant; when this interval exists, the upper and back part of the kidney is separated from the pleura by areolar tissue only. The largest artery in the human body, the aorta originates from the left ventricle of the heart and brings oxygenated blood to all parts of the body in the systemic circulation. ... The azygos vein is so named because it is unpaired, having no matching vein on the left side of the body. ... In human anatomy, the thoracic duct is an important part of the lymphatic system — it is the largest lymphatic vessel in the body. ... The azygos vein is so named because it is unpaired, having no matching vein on the left side of the body. ... The esophagus (also spelled oesophagus/Å“sophagus), or gullet is the muscular tube in vertebrates through which ingested food passes from the mouth area to the stomach. ... The vagus nerve (or pneumogastric nerve) is the tenth of twelve paired cranial nerves, and is the only nerve that starts in the brainstem (within the medulla oblongata) and extends, through the jugular foramen, down below the head, to the abdomen. ... The thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. ... This page is about the muscular organ, the Heart. ... This article may be too technical for most readers to understand. ... The phrenic nerve arises from the third, fourth, and fifth cervical spinal nerves (C3-C5). ... The splanchnic nerves are part of the autonomic nervous system. ... The splanchnic nerves are part of the autonomic nervous system. ... The Hemiazygos Vein (vena azygos minor inferior) begins in the left ascending lumbar or renal vein. ... The word sympathetic means different things in different contexts. ... In human anatomy, superior epigastric artery refers to a blood vessel that carries oxygenated blood and arises from the internal thoracic artery. ... In human anatomy, the internal thoracic artery (ITA) (previously known as the internal mammary artery) is a vessel that supplies the chest wall and mamma, a term used for breast in anatomy. ... In mammals including humans, the lymphatic vessels (or lymphatics) are a network of thin tubes that branch, like blood vessels, into tissues throughout the body. ... Human kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... In anatomy, the pleural cavity is the potential space between the lungs and the chest wall. ...


Variations

The sternal portion of the muscle is sometimes wanting and more rarely defects occur in the lateral part of the central tendon or adjoining muscle fibers.


See also

In the human body, the midriff is the section of the body between the chest and the waist. ...

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. GPnotebook is a British medical database for general practitioners (GPs. ... Loyola University Chicago is a private co-educational religious-affiliated university established in Chicago, Illinois in 1870 as Saint Ignatius College. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...

Muscles of the Head -- Neck -- Trunk -- Upper limb -- Lower limb -- LIST OF ALL MUSCLES

BACK: splenius capitis | splenius cervicis | sacrospinalis | semispinalis | multifidus | rotatores | interspinales | intertransversarii | (Gray's s115) A top-down view of skeletal muscle Muscle is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... This is a list of muscles of the human anatomy. ... The human back is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders. ... The Splenius capitis muscle is a muscle of the human body. ... The xxxxx is a muscle of the human body. ... The Sacrospinalis muscle is a muscle of the human body. ... The Semispinalis muscle is a muscle of the human body. ... The Multifidus muscle is a muscle of the human body. ... The Rotatores muscle is a muscle of the human body. ... these muscles sometimes hurt me. ... Intertransversarii muscles The Intertransversarii are small muscles placed between the transverse processes of the vertebræ. In the cervical region they are best developed, consisting of rounded muscular and tendinous fasciculi, and are placed in pairs, passing between the anterior and the posterior tubercles respectively of the transverse processes of two... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


SUBOCCIPITAL : rectus capitis posterior (major, minor) | obliquus capitis (inferior, superior) | (Gray's s116) The first spinal nerve, the suboccipital nerve exits the spinal cord between the skull and the first cervical vertebra, the atlas. ... The Rectus capitis posterior major muscle is a muscle of the human body. ... The Rectus capitis posterior minor muscle is a muscle of the human body. ... In anatomy, the obliquus capitis inferior muscle, the larger of the two oblique muscles, is one of the muscles of the neck. ... It arises from the lateral mass of the atlas bone. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


THORAX: intercostales (externi, interni) | subcostales | transversus thoracis | levatores costarum | serratus posterior (inferior, superior) | diaphragm | (Gray's s117) Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body that lies between the head and the abdomen. ... The Intercostales externi muscle is a muscle of the human body. ... The Intercostales interni (Internal intercostals) are eleven in number on either side. ... The Subcostales muscle is a muscle of the human body. ... The tranversus thoracis lies internal to the thoracic cage, anteriorly. ... The Levatores costarum, twelve in number on either side, are small tendinous and fleshy bundles, which arise from the ends of the transverse processes of the seventh cervical and upper eleven thoracic vertebrae; they pass obliquely downward and lateralward, like the fibers of the Intercostales externi, and each is inserted... The Serratus posterior inferior muscle is a muscle of the human body. ... The Serratus posterior superior muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


ABDOMEN: obliques (external, internal) | transversus abdominis | rectus abdominis | pyramidalis | cremaster | quadratus lumborum | (Gray's s118) The human abdomen The human abdomen (from the Latin word meaning belly) is the part of the body between the pelvis and the thorax. ... The Obliquus externus abdominis muscle (or external oblique) is a muscle of the human body. ... The internal oblique is the intermediate muscle of the abdomen, lying just underneath the external oblique and just above (superficial to) the transverse abdominal muscle. ... The transversus abdominis muscle, also known as the transverse abdominal muscle, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle. ... The rectus abdominis muscle is a paired muscle running vertically on each side of the anterior wall of the human abdomen (and in some animals). ... The pyramidalis is a muscle that is considered insignificant in humans. ... The cremaster muscle is a muscle that covers the testis. ... The Quadratus lumborum muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


PELVIS: levator ani (iliococcygeus, pubococcygeus) | coccygeus | (Gray's s119) Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... The Levator ani is a broad, thin muscle, situated on the side of the pelvis. ... The Iliococcygeus arises from the ischial spine and from the posterior part of the tendinous arch of the pelvic fascia, and is attached to the coccyx and anococcygeal raphé; it is usually thin, and may fail entirely, or be largely replaced by fibrous tissue. ... Muscles of the lower abdomen. ... The Coccygeus is situated behind the levator ani. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


PERINEUM: corrugator cutis ani | sphincter ani (externus, internus) | transversus perinei superficialis | bulbospongiosus | ischiocavernosus | Transversus perinei profundus sphincter urethrae membranaceae | (Gray's s120) The muscles of the male perineum In anatomy, the perineum is the region between the genital area and the anus in both sexes. ... The Corrugator cutis ani muscle is a muscle of the human body. ... The Sphincter ani externus muscle is a muscle of the human body. ... The Sphincter ani internus muscle is a muscle of the human body. ... The Transversus perinei superficialis muscle is a muscle of the human body. ... Bulbospongiosus is one of the superficial muscles of the perineum. ... The ischiocavernosus muscle is a muscle just below the surface of the perineum, present in both men and women. ... The Transversus perinei profundus muscle is a muscle of the human body. ... The Sphincter urethrae membranaceae muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


  Results from FactBites:
 
Diaphragm (anatomy) - MSN Encarta (169 words)
Diaphragm (anatomy), wide muscular partition separating the thoracic, or chest cavity, from the abdominal cavity.
In humans the diaphragm is attached to the lumbar vertebrae, the lower ribs, and the sternum or breastbone.
A hiccup is caused by a spasmodic, involuntary contraction of the diaphragm.
Diaphragm (anatomy) Summary (2251 words)
The Diaphragm is a dome-shaped musculofibrous septum which separates the thoracic from the abdominal cavity, its convex upper surface forming the floor of the former, and its concave under surface the roof of the latter.
The central tendon of the diaphragm is a thin but strong aponeurosis situated near the center of the vault formed by the muscle, but somewhat closer to the front than to the back of the thorax, so that the posterior muscular fibers are the longer.
The diaphragm is pierced by a series of apertures to permit of the passage of structures between the thorax and abdomen.
  More results at FactBites »

 
 

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