Diaphragm
Respiratory system
Latin	diaphragma
Gray's	subject #117 404
Artery	Pericardiacophrenic artery, Musculophrenic artery, Inferior phrenic arteries
Vein	Superior phrenic vein, Inferior phrenic vein
Nerve	phrenic and lower intercostal nerves
Precursor	septum transversum, pleuroperitoneal folds, body wall [1]
MeSH	Diaphragm
Dorlands/Elsevier	d_15/12293509

For other types of diaphragm, see Diaphragm. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Arteries are Blood vessels that carry blood away from the Heart. The pericardiacophrenic artery is a long slender branch of the Internal thoracic artery. The Musculophrenic Artery arises from the Internal thoracic artery, directed obliquely downward and lateralward behind the cartilages of the False ribs; it perforates The inferior phrenic arteries are two small vessels which supply the diaphragm but present much variety in their origin In the Circulatory system, a vein is a Blood vessel that carries Blood back toward the Heart (as opposed to Artery, a blood vessel The superior phrenic vein, ie the vein accompanying the Pericardiacophrenic artery, usually opens into the Internal mammary vein. The Inferior Phrenic Veins drain the diaphragm and follow the course of the Inferior phrenic arteries; the right ends in the Inferior vena cava; A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. The phrenic nerve arises from the third fourth and fifth cervical Spinal nerves (C3-C5 in Humans. The intercostal nerves are the anterior divisions (rami anteriores ventral divisions of the Thoracic spinal nerves from T1 to T11 Embryology (from Greek grc ἔμβρυον embryon, "unborn embryo" and grc -λογία -logia) is the study of the development The septum transversum is a thick mass of cranial Mesenchyme that gives rise to parts of the Thoracic diaphragm and the Ventral mesentery of the foregut Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Elsevier, the world's largest Publisher of Medical and Scientific literature, forms part of the Reed Elsevier group

In the anatomy of mammals, the thoracic diaphragm is a sheet of muscle extending across the bottom of the ribcage. Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the In Vertebrate Anatomy, ribs ( Latin costae) are the long curved Bones which form the ribcage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in respiration. 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 The abdominal cavity is the Body cavity of the human body (and animal bodies that holds the bulk of the viscera and which is located below (or inferior In Animal physiology, respiration is the transport of Oxygen from the outside air to the cells within tissues and the transport of Carbon dioxide A diaphragm in anatomy can refer to other flat structures such as the urogenital diaphragm or pelvic diaphragm, but "the diaphragm" generally refers to the thoracic diaphragm. The deep perineal pouch (also deep perineal space) is an anatomical term that refers to the space enclosed in part by the Perineum, and located superior to the The pelvic floor or pelvic/urogential diaphragm is composed of muscle fibers of the Levator ani, the Coccygeus, and associated Connective tissue Other vertebrates such as amphibians and reptiles have diaphragms or diaphragm-like structures, but important details of the anatomy vary, such as the position of lungs in the abdominal cavity. Prehistoric amphibian Amphibians (class Amphibia such as Frogs Toads Salamanders Newts Gymnophiona, Sirens and Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers

Function

The diaphragm is crucial for breathing and respiration. Breathing takes Oxygen in and Carbon dioxide out of the body Aerobic Organisms require oxygen to create energy via respiration, in In Animal physiology, respiration is the transport of Oxygen from the outside air to the cells within tissues and the transport of Carbon dioxide During inhalation, the diaphragm contracts, thus enlarging the thoracic cavity (the external intercostal muscles also participate in this enlargement). Intercostal muscles are several groups of Muscles that run between the Ribs, and help form and move the Chest wall. This reduces intra-thoracic pressure: in other words, enlarging the cavity creates suction that draws air into the lungs. lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive When the diaphragm relaxes, air is exhaled by elastic recoil of the lung and the tissues lining the thoracic cavity in conjunction with the abdominal muscles which act as an antagonist paired with the diaphragm's contraction. The human abdomen (from the Latin word meaning "belly" is the part of the body between the Pelvis and the thorax. An antagonist is a classification used to describe a Muscle that acts in opposition to the specific movement generated by the agonist and is responsible for

It is not responsible for all the breathing related to voice, a common misconception espoused by many teachers but few great singers. One has more control over the abdominals and intercostals than the actual diaphragm, which has relatively few proprioceptive nerve endings. The human abdomen (from the Latin word meaning "belly" is the part of the body between the Pelvis and the thorax. Intercostal muscles are several groups of Muscles that run between the Ribs, and help form and move the Chest wall. Proprioception (ˌproʊpriːəˈsɛpʃən PRO -pree-o-SEP-shun from Latin proprius, meaning "one's own" and perception is the Sense By training proper posture and balance in the rest of the body, the diaphragm naturally strengthens and works in concert with surrounding structures rather than in isolation.

The diaphragm is also involved in non-respiratory functions, helping to expel vomit, feces, and urine from the body by increasing intra-abdominal pressure, and preventing acid reflux by exerting pressure on the esophagus as it passes through the esophageal hiatus. Vomiting (also called throwing up, emesis) is the forceful expulsion of the contents of one's Stomach through the Mouth and sometimes the Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus Urine is a liquid waste product of the body secreted by the Kidneys by a process of filtration from Blood and Excreted through the Urethra. Gastroesophageal reflux disease ( American English and Canadian English) or Gastro-oesophageal reflux disease ( British English, Hiberno-English The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in In human anatomy the esophageal hiatus is a hole in the diaphragm through which the Esophagus passes

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. This article uses a few professional terms to explain certain anatomical details

The muscular fibers may be grouped according to their origins into three parts:

There are two lumbocostal arches, a medial and a lateral, on either side. The medial arcuate ligament (also medial lumbocostal arch) is tendinous fascia that arches over the Psoas major muscle as it passes through the diaphragm The lateral arcuate ligament (also lateral lumbocostal arch) is a Ligament under the diaphragm that arches across the upper part of the Quadratus lumborum

Innervation

The diaphragm is innervated by the phrenic nerve. The phrenic nerve arises from the third fourth and fifth cervical Spinal nerves (C3-C5 in Humans.

Crura and central tendon

At their origins the crura are tendinous in structure, and blend with the anterior longitudinal ligament of the vertebral column. The crura of the diaphragm (singular=crus are tendinous structures that extend downward from the diaphragm to attach to the Vertebral column. The anterior longitudinal ligament is a Ligament that runs down the anterior surface of the spine. In Human anatomy, the vertebral column ( backbone or spine) is a column of 34 Vertebrae the Sacrum, Intervertebral

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 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 The thorax is a division of an Animal 's body that lies between the head and the Abdomen.

Openings in the Diaphragm

Inferior view of the human diaphragm, showing openings

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 cava—and a series of smaller ones are described. The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The inferior vena cava (or IVC is the large Vein that carries de-oxygenated Blood from the lower half of the body into the Heart.

Diaphragm and pleural cavities in amphibian (left), bird (center), mammal (right). a, mandible; b, genio-hyoid; c, hyoid; d, sterno-hyoid; e, sternum; f, pericardium; g, septum transversum; h, rectus abdominis; i, abdominal cavity; j, pubis; k, esophagus; l, trachea; m, cervical limiting membrane of abdominal cavity; n, dorsal wall of body; o, lung; o', air-sac. The mandible (from Latin mandibula, "jawbone" or inferior maxillary bone forms the lower Jaw and holds the lower teeth in place The Geniohyoid muscle is a narrow Muscle situated superior to the medial border of the Mylohyoid muscle. The hyoid bone ( lingual bone) (Latin os hyoideum) is a Bone in the Neck, and is the only bone in the human skeleton not articulated to any The sternohyoid muscle is a thin narrow muscle attaching the Hyoid bone to the Sternum, one of the paired Strap muscles of the Infrahyoid muscles The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest The pericardium is a double-walled sac that contains the Heart and the roots of the Great vessels. The septum transversum is a thick mass of cranial Mesenchyme that gives rise to parts of the Thoracic diaphragm and the Ventral mesentery of the foregut The rectus abdominis muscle (commonly known as "abs" is a paired Muscle running vertically on each side of the anterior wall of the human abdomen (and in some other The abdominal cavity is the Body cavity of the human body (and animal bodies that holds the bulk of the viscera and which is located below (or inferior For the bone in many mammals often called the penis bone see Baculum The android pubic bone is the Ventral and Anterior The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The traceartes, or windpipe, is a tube that has an inner diameter of about 20-25 mm and a length of about 10-16 cm in humans lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive Bird anatomy, or the physiological structure of Birds ^[2]

Comparative anatomy and evolution

The existence of some membrane separating the pharynx from the stomach can be traced widely among the chordates. Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates Thus amphioxus possesses an atrium by which water exits the pharynx, which has been argued (and disputed) to be homologous to structures in ascidians and hagfishes. The lancelets (subphylum Cephalochordata, traditionally known as amphioxus) are a group of primitive Chordates. Ascidiacea (commonly known as the ascidians or Sea squirts is a class in the Tunicata Subphylum of sac-like marine Filter feeders Hagfish are marine Craniates of the class Myxini, also known as Hyperotreti. ^[3] The urochordate epicardium separates digestive organs from the pharynx and heart, but the anus returns to the upper compartment to discharge wastes through an outgoing siphon.

Thus the diaphragm emerges in the context of a body plan which separated an upper feeding compartment from a lower digestive tract, but the point at which it originates is a matter of definition. Structures in fish, amphibians, reptiles, and birds have been called diaphragms, but it has been argued that these structures are not homologous. For instance, the alligator diaphragmaticus muscle does not insert on the esophagus and does not affect pressure of the lower esophageal sphincter. The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in ^[4] The lungs are located in the abdominal compartment of amphibians and reptiles, so that contraction of the diaphragm expels air from the lungs rather than drawing it into them. In birds and mammals lungs are located above the diaphragm. The presence of an exceptionally well preserved fossil of Sinosauropteryx, with lungs located beneath the diaphragm as in crocodiles, has been used to argue that dinosaurs could not have sustained an active warm-blooded physiology, or that birds could not have evolved from dinosaurs. Sinosauropteryx (meaning "Chinese lizard-wing" is the first and most primitive Genus of Dinosaur found with the fossilized impressions of ^[5] An explanation for this state of affairs is that when lungs originated beneath the diaphragm, but as the demands for respiration increased in warm-blooded birds and mammals, natural selection came to favor the parallel evolution of the herniation of the lungs from the abdominal cavity in both lineages. Parallel evolution is the independent evolution of similar traits starting from a similar ancestral condition due to similar environments or other evolutionary pressures ^[2]

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.

X-ray of chest, showing top of diaphragm. X-radiation (composed of X-rays) is a form of Electromagnetic radiation.

Pathology

A hiatal hernia can result from a tear or weakness in the diaphragm near the gastroesophageal junction. A hiatus hernia or hiatal hernia is the protrusion (or Herniation) of the upper part of the Stomach into the Thorax through a tear or weakness The cardia (also known as Z-line or esophagogastric junction or gastroesophageal junction) is the anatomical term for the junction orifice of

If the diaphragm is struck, or otherwise spasms, breathing will become difficult. 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 This is called "having the wind knocked out of you. Getting the wind knocked out of you is a phrase that mainly refers to a kind of diaphragm spasm that occurs when sudden force is applied to the abdomen which puts pressure "

A hiccup occurs when the diaphragm contracts periodically without voluntary control. A hiccup or hiccough (normally pronounced "HICK-up" ˈhɪkʌp also known as a condition of singulitis is the Spasmodic contraction of the diaphragm

Diaphragmatic injuries result from either blunt or penetrating trauma.

Gas under the diaphragm may be pneumoperitoneum. Pneumoperitoneum is air or gas in the abdominal (peritoneal cavity

Additional images

The phrenic nerve and its relations with the vagus nerve.	Plan of right sympathetic cord and splanchnic nerves.	Thoracic portion of the sympathetic trunk.	The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.
Front view of the thoracic and abdominal viscera.	The duodenum and pancreas.	Topography of thoracic and abdominal viscera.	Organs of abdomen
Peritoneopericardial diaphragmatic hernia in a cat. Diaphragmatic hernia is a defect or hole in the diaphragm that allows the abdominal contents to move into the chest cavity	Hiatal hernia	Probably the first dictionary definition of "diaphragm"

See also

• midriff

References

1. ^ mslimb-012 — Embryology at UNC
2. ^ ^{a b} Arthur Keith, M. A hiatus hernia or hiatal hernia is the protrusion (or Herniation) of the upper part of the Stomach into the Thorax through a tear or weakness In the human body the midriff is the section of the body between the Chest and the Waist, i The University of North Carolina at Chapel Hill ( UNC, North Carolina, or simply Carolina) is a public, Coeducational Research D. (1905). The nature of the mammalian diaphragm and pleural cavities.
3. ^ Zbynek Kozmik et al. (1999). Characterization of an amphioxus paired box gene, AmphiPax2/5/8 1295-1304.
4. ^ T. J. Uriona et al. (2005). Structure and function of the esophagus of the American alligator (Alligator mississippiensis) 3047-3053.
5. ^ Lung fossils suggest that dinos breathed in cold blood.

External links

• 483393594 at GPnotebook
• LUC dph

This article was originally based on an entry from a public domain edition of Gray's Anatomy. GPnotebook is a British medical database for General practitioners (GPs Loyola University Chicago is a private co-educational Jesuit university established in Chicago in 1870 as Saint Ignatius College The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone Henry Gray's Anatomy of the Human Body (or Gray's Anatomy as it has commonly been shortened is an English-language Human anatomy Textbook 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.