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Abdominal quadrants, regions and planes
Anatomy of the anterolateral abdominal wall
Anatomy of the abdominal viscera: Blood supply of the foregut, midgut and hindgut
Anatomy of the abdominal viscera: Esophagus and stomach
Anatomy of the abdominal viscera: Small intestine
Anatomy of the abdominal viscera: Large intestine
Anatomy of the abdominal viscera: Pancreas and spleen
Anatomy of the abdominal viscera: Kidneys, ureters and suprarenal glands
Anatomy of the abdominal viscera: Innervation of the abdominal viscera
Anatomy of the abdominal viscera: Liver, biliary ducts and gallbladder
Anatomy of the diaphragm
Anatomy of the inguinal region
Anatomy of the muscles and nerves of the posterior abdominal wall
Anatomy of the peritoneum and peritoneal cavity
Anatomy of the vessels of the posterior abdominal wall
Anatomy clinical correlates: Anterior and posterior abdominal wall
Anatomy clinical correlates: Viscera of the gastrointestinal tract
Anatomy clinical correlates: Peritoneum and diaphragm
Anatomy clinical correlates: Other abdominal organs
Anatomy clinical correlates: Inguinal region
Anatomy of the diaphragm
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Central: Phrenic nervesPeripheral: T5-T11 intercostal nerves and subcostal nerves
Evode Iradufasha, MD
Patricia Nguyen, MScBMC
The diaphragm is a dome-shaped sheet of skeletal muscle that divides the thoracic cavity from the abdominal cavity.
That may sound simple, but in fact, the diaphragm is so much more than just a sheet of muscle. In fact, every breath you take is thanks to your diaphragm!
Ok, so let’s begin by looking at the general structure of the diaphragm. It curves superiorly into right and left domes.
It has a mobile, central portion known as the central tendon and a peripheral muscular portion that is fixed to the bones, cartilages, and ligaments of the thoracic cage.
The periphery of the diaphragm can be divided into three parts depending on its specific attachment points.
The sternal part, attaches to the posterior aspect of the xiphoid process; the costal part attaches to the internal surfaces of the 7th to the 12th ribs and their costal cartilages; while the lumbar part attaches to the medial and lateral arcuate ligaments, the L1 to L3 vertebral bodies and the intervertebral discs in between.
Now, the diaphragm is the chief muscle for inspiration; meaning that when it contracts, it helps us breathe in. During contraction, the central portion of the diaphragm depresses, increasing the volume of the thoracic cavity, which, in turn, increases the volume in the lungs.
This makes the intrapulmonary pressure fall below the atmospheric pressure, creating a partial vacuum that allows fresh air to be sucked in!
On the other hand, expiration is largely passive, meaning the diaphragm relaxes and rises, which decreases the volume of the thoracic cavity, and subsequently increases the intrapulmonary pressure to be above the atmospheric pressure, forcing the air in the lungs to be expelled out.
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