Abdomen

Abdomen
Anatomy Abdomen Tiesworks.jpg
The human abdomen and organs which can be found beneath the surface
Abdomen-periumbilical region.png
Details
InsertionRib cage
Vertebral column
ActionsMovement and support for the torso
Assistance with breathing
Protection for the inner organs
Postural support
Identifiers
LatinAbdomen
D000005
A01.1.00.016
9577
Anatomical terminology

The abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The region occupied by the abdomen is termed the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax.[1][2] The abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint (the intervertebral disc between L5 and S1) to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.

Structure

Contents

The relations of the viscera and large vessels of the abdomen, seen from behind.

The abdomen contains most of the tubelike organs of the digestive tract, as well as several solid organs. Hollow abdominal organs include the stomach, the small intestine, and the colon with its attached appendix. Organs such as the liver, its attached gallbladder, and the pancreas function in close association with the digestive tract and communicate with it via ducts. The spleen, kidneys, and adrenal glands also lie within the abdomen, along with many blood vessels including the aorta and inferior vena cava. Anatomists may consider the urinary bladder, uterus, fallopian tubes, and ovaries as either abdominal organs or as pelvic organs. Finally, the abdomen contains an extensive membrane called the peritoneum. A fold of peritoneum may completely cover certain organs, whereas it may cover only one side of organs that usually lie closer to the abdominal wall. Anatomists call the latter type of organs retroperitoneal.

Abdominal organs can be highly specialized in some animals. For example, the stomach of ruminants (a suborder of mammals) is divided into four chambers – rumen, reticulum, omasum and abomasum.[3] In vertebrates, the abdomen is a large cavity enclosed by the abdominal muscles, ventrally and laterally, and by the vertebral column dorsally. Lower ribs can also enclose ventral and lateral walls. The abdominal cavity is upper part of the pelvic cavity. It is attached to the thoracic cavity by the diaphragm. Structures such as the aorta, inferior vena cava and esophagus pass through the diaphragm. Both the abdominal and pelvic cavities are lined by a serous membrane known as the parietal peritoneum. This membrane is continuous with the visceral peritoneum lining the organs.[4] The abdomen in vertebrates contains a number of organs belonging, for instance, to the digestive tract and urinary system.

Muscles

(Left) Henry Gray (1825–1861). Anatomy of the Human Body.
(Right) A male abdomen

There are three layers of the abdominal wall. They are, from the outside to the inside: external oblique, internal oblique, and transverse abdominal.[5] The first three layers extend between the vertebral column, the lower ribs, the iliac crest and pubis of the hip. All of their fibers merge towards the midline and surround the rectus abdominis in a sheath before joining up on the opposite side at the linea alba. Strength is gained by the criss-crossing of fibers, such that the external oblique are downward and forward, the internal oblique upward and forward, and the transverse abdominal horizontally forward.[5]

The transverse abdominal muscle is flat and triangular, with its fibers running horizontally. It lies between the internal oblique and the underlying transverse fascia. It originates from Poupart's ligament, the inner lip of the ilium, the lumbar fascia and the inner surface of the cartilages of the six lower ribs. It inserts into the linea alba behind the rectus abdominis.

The rectus abdominis muscles are long and flat. The muscle is crossed by three fibrous bands called the tendinous intersections. The rectus abdominis is enclosed in a thick sheath formed, as described above, by fibers from each of the three muscles of the lateral abdominal wall. They originate at the pubis bone, run up the abdomen on either side of the linea alba, and insert into the cartilages of the fifth, sixth, and seventh ribs. In the region of the groin, the inguinal canal, a passage through the layers. This gap is where the testes can drop through the wall and where the fibrous cord from the uterus in the female runs. This is also where weakness can form, and cause inguinal hernias.[5]

The pyramidalis muscle is small and triangular. It is located in the lower abdomen in front of the rectus abdominis. It originates at the pubic bone and is inserted into the linea alba halfway up to the navel.

Other Languages
العربية: بطن
aragonés: Abdomen
ܐܪܡܝܐ: ܟܪܣܐ
asturianu: Abdome
Avañe'ẽ: Tyeguy
авар: Чехь
azərbaycanca: Abdomen
বাংলা: উদর
Bahasa Banjar: Abdomén
Bân-lâm-gú: Pak-tó͘
български: Корем
brezhoneg: Kof
català: Abdomen
Чӑвашла: Хырăм
čeština: Břicho
Cymraeg: Abdomen
dansk: Bughule
Deutsch: Abdomen
eesti: Kõht
Ελληνικά: Κοιλιά
español: Abdomen
Esperanto: Ventro
estremeñu: Abdomin
euskara: Abdomen
فارسی: شکم
français: Abdomen
Frysk: Búk
Gaeilge: Abdóman
Gàidhlig: Balg
galego: Abdome
客家語/Hak-kâ-ngî: Tú-sṳ́
한국어: 배 (해부학)
हिन्दी: उदर
hrvatski: Trbuh
Bahasa Indonesia: Abdomen
interlingua: Abdomine
íslenska: Afturbolur
italiano: Addome
עברית: בטן
Basa Jawa: Weteng
ಕನ್ನಡ: ಉದರ
қазақша: Абдомен
Kreyòl ayisyen: Vant
kurdî: Zikê mirov
Кыргызча: Абдомен
лакку: Лякьа
Latina: Abdomen
latviešu: Vēders
lietuvių: Pilvas
Limburgs: Boek
lingála: Libumu
Lingua Franca Nova: Adomen
lumbaart: Venter
magyar: Has
македонски: Стомак
მარგალური: ქვარა
مازِرونی: اشکم
Bahasa Melayu: Abdomen
Mìng-dĕ̤ng-ngṳ̄: Bók-lō̤
Nāhuatl: Xillantli
Nederlands: Buik
Nedersaksies: Boek (lichem)
नेपाली: पेट
日本語:
norsk: Abdomen
norsk nynorsk: Abdomen
occitan: Abdomèn
oʻzbekcha/ўзбекча: Abdomen
پښتو: گېډه
Tok Pisin: Bel
polski: Brzuch
português: Abdómen
Ripoarisch: Buch (Körperdeel)
română: Abdomen
Runa Simi: Wiksa
русский: Живот
संस्कृतम्: नाभिः
Scots: Abdomen
shqip: Abdomeni
sicilianu: Panza
Simple English: Abdomen
slovenčina: Brucho (stavovce)
slovenščina: Trebuh
српски / srpski: Трбух
srpskohrvatski / српскохрватски: Trbuh
Basa Sunda: Beuteung
suomi: Vatsa
svenska: Buken
Tagalog: Puson
தமிழ்: வயிறு
తెలుగు: ఉదరము
Türkçe: Karın
українська: Живіт
ئۇيغۇرچە / Uyghurche: قورساق قىسم
Vahcuengh: Dungx
vepsän kel’: Koht
Tiếng Việt: Bụng
文言:
West-Vlams: Buuk
Winaray: Puson
ייִדיש: בויך
粵語:
Zazaki: Vêre
中文: