the musculomembranous partition separating the thoracic and abdominal cavities. On its sides it is attached to the six lower ribs, at its front to the sternum, and at its back to the spine. The esophagus, aorta, vena cava, and numerous nerves pass through the diaphragm. When relaxed it is convex, but it flattens as it contracts during inhalation, thereby enlarging the chest cavity and allowing for expansion of the lungs. See also respiration
2. any separating membrane or structure.
3. a disk with one or more openings or with an adjustable opening, mounted in relation to a lens or source of radiation, by which part of the light or radiation may be excluded from the area.
a shallow dome-shaped disk used as a contraceptive
, made of a soft plastic material such as latex. Its anterior lip fits behind the symphysis pubis and its posterior lip rests in the posterior fornix. It is used with a spermicide
to prevent entrance of spermatozoa
into the cervical os. See also contraception
pelvic diaphragm the portion of the floor of the pelvis formed by the coccygeus muscles and the levator ani muscles, and their fascia.
polyarcuate diaphragm one showing abnormal scalloping of margins on radiographic visualization.
urogenital diaphragm a traditional but no longer valid concept that superior and inferior layers enclose the sphincter urethrae and deep transverse perineal muscles and together form a musculomembranous sheet that extends between the ischiopubic rami.
diaphragm (di'a-fram?) [Gr. diaphragma, a partition]
1. A thin membrane as is used for dialysis.
2. In microscopy, an apparatus located beneath the opening in the stage and permitting regulation of the amount of light passing through the object.
3. A rubber or plastic cup that fits over the cervix uteri, used for contraceptive purposes. See: illustration
MOVEMENT OF RIB CAGE AND DIAPHRAGM DURING RESPIRATION: A. Inspiration: Air drawn into lungs; B. Expiration: Air forced out of lungs
The dome-shaped skeletal muscle that separates the abdomen from the thoracic cavity with its convexity upward. It contracts to promote inhalation, flattening downward and permitting the lungs to expand. It relaxes to promote exhalation, rising to its dome-shaped position and compressing the lungs.
The origin of the diaphragm is the xiphoid process, the lower six costal cartilages, and the lumbar vertebrae. The diaphragm is directly superior to the liver, the stomach, the spleen, the adrenal glands, and the kidneys; the right side is slightly higher than the left. See: illustration; Boerhaave syndrome
Bucky diaphragm See: Bucky, Gustav P.
hernia of diaphragm
A congenital or traumatic protrusion of abdominal contents through the diaphragm.
pelvic diaphragmPelvic floor.
Potter-Bucky diaphragmBucky diaphragm.
A gap between the foot processes of podocytes in the renal glomerulus, composed of a filter made of proteins that holds large molecules within the plasma but allows smaller soluble chemicals to pass with water into the urine.
The urogenital trigone, or triangular ligament. A musculofascial sheath that lies between the ischiopubic rami, it is superficial to the pelvic diaphragm. In males it surrounds the membranous urethra; in females, the vagina. illustration