The diaphragm is the thin, dome-shaped muscular partition which separates the cavity of the abdomen from that of the chest. It is of great importance in respiration, playing the chief part in ?lling the lungs. During deep respiration its movements are responsible for 60 per cent of the total amount of air breathed, and in the horizontal posture, or in sleep, an even greater percentage.
The description ‘diaphragm’ is also used for the hemispherical rubber (‘dutch’) cap used in conjunction with a chemical spermicide as a contraceptive. It ?ts over the neck of the uterus (cervix) inside the vagina. (See CONTRACEPTION.)
n. 1. (in anatomy) a thin musculomembranous dome-shaped muscle that separates the thoracic and abdominal cavities. The diaphragm is attached to the lower ribs at each side and to the breastbone and the backbone at the front and back. It bulges upwards against the heart and the lungs, arching over the stomach, liver, and spleen. There are openings in the diaphragm through which the oesophagus, blood vessels, and nerves pass. The diaphragm plays an important role in *breathing. It contracts with each inspiration, becoming flattened downwards and increasing the volume of the thoracic cavity. With each expiration it relaxes and is restored to its dome shape. 2. a hemispherical rubber cap fitted inside the vagina over the neck (cervix) of the uterus as a contraceptive. When combined with the use of a chemical spermicide the diaphragm provides reliable contraception with a failure rate as low as 2–10 pregnancies per 100 woman-years.
(CDH) herniation of the fetal abdominal organs into the fetal chest, which occurs in one in 2000–5000 live births. This leads to pulmonary *hypoplasia, which is the main cause of the associated high neonatal mortality. The risk of pulmonary hypoplasia is substantially greater where there is herniation of the liver into the thoracic cavity. CDH is commonly associated with additional structural abnormalities (cardiac, neural tube defects, and exomphalos), and the risk of chromosomal abnormality (*aneuploidy) is 10–20%. Demonstration of a fluid-filled bowel at the level of the heart on ultrasound is diagnostic.... congenital diaphragmatic hernia
the radiological sign of a raised diaphragm, which is observed in many conditions including *subphrenic abscess, previous abdominal surgery, *peritonitis, damage to the nerve innervating the diaphragm (the phrenic nerve), and various lung-related disease processes.... tented diaphragm
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