Abdomen

A roughly cylindrical chamber extending from the inferior margin of the thorax to the superior margin of the pelvis and lower limb

Abdomen

Forms the superior opening to the abdomen, closed by the diaphragm

Inferior thoracic aperture

Inferiorly, the deep abdominal wall is continuous with the Pelvic wall at the ____.

Pelvic inlet

The cavity enclosed by the abdominal wall that freely communicates with the pelvic cavity

Peritoneal cavity

what is suspended in the peritoneal cavity by mesenteries or positioned between the cavity and musculoskeletal wall

Abdominal viscera

Functions of the Abdomen

Houses and protects major viscera and breathing

The abdominal viscera partly protected by the thoracic wall because they lie beneath the domes of the diaphragm

Much of the Liver, gallbladder, stomach, spleen, and parts of the colon

The urinary organs located deep to the lower ribs

Superior poles of the kidneys

The structures that predominantly support and protect abdominal viscera not located beneath the diaphragmatic domes

Muscular abdominal walls

When the abdominal wall relaxes to accommodate expansion of the thoracic cavity and the inferior displacement of abdominal viscera during contraction of the diaphragm?

Inspiration

When the abdominal wall contracts to assist in elevating the domes of the diaphragm, thus reducing thoracic volume?

Expiration

The type of expiration that can expel material from the airway using abdominal muscles

Forced expiration

Two examples of forced expiration using the abdominal muscles

Coughing and sneezing

The pressure within the abdominal cavity that can be dramatically increased by contraction of the abdominal wall when the diaphragm is in a fixed position

Intraabdominal pressure

The mechanism retaining air in the lungs during increased intraabdominal pressure

Closing valves in the larynx in the neck

The bodily processes aided by increased intraabdominal pressure

Voiding bladder contents(micturition), voiding rectal contents(defecation), and childbirth

Skeletal elements of the abdominal wall

L5 and their intervertebral discs, superior expanded parts of the pelvic bones, and bony components of the inferior thoracic wall(costal margin, rib XII, end of rib XI, and xiphoid process)

The three muscles reinforcing the posterior abdominal wall lateral to the vertebral column

Quadratus lumborum, psoas major, and iliacus

Muscles that pass into the thigh and are major flexors of the hip joint.

Distal ends of the psoas major and iliacus

The three muscle layers predominantly forming the lateral abdominal wall

Transversus abdominis, internal oblique, and external oblique

The orientation of the three lateral abdominal-wall muscle layers compared with thoracic muscles

Similar to the orientation of the intercostal muscles

The anterior paired segmented vertical muscle spanning between the inferior thoracic wall and pelvis

Rectus abdominis

The tissue providing structural continuity posteriorly in the abdominal wall

Thick fascia

The flat tendinous sheets providing structural continuity between lateral and anterior abdominal-wall regions; derived from muscles of the lateral wall.

Aponeuroses

The central digestive tube suspended from the abdominal wall by mesenteries

Gut tube (gastrointestinal system)

The thin sheets of tissue suspending the gastrointestinal tract from abdominal walls

Mesenteries

The mesentery associated with proximal regions of the gut tube

Ventral (anterior) mesentery

The mesentery extending along the entire length of the gastrointestinal system

Dorsal (posterior) mesentery

The basis for naming different portions of the ventral and dorsal mesenteries

According to the organs they suspend or with which they are associated

The membrane lining the abdominal cavity

Peritoneum

The epithelial-like single layer of cells forming part of the peritoneum together with a supportive layer of connective tissue.

Mesothelium

The thoracic membranes comparable to the peritoneum

Pleura and serous pericardium in the thorax

The part of the peritoneum lining the abdominal wall

Parietal peritoneum

The part of the peritoneum covering suspended organs

Visceral peritoneum

The normally potential space between visceral and parietal peritoneum

Peritoneal cavity

The two major positional categories of abdominal viscera

Intraperitoneal and retroperitoneal

An abdominal structure suspended by a mesentery within the peritoneal cavity such as the elements of the GI system.

Intraperitoneal structure

An abdominal structure positioned between the parietal peritoneum and abdominal wall without a mesentery

Retroperitoneal structure

The two primary urinary structures that develop and remain behind the peritoneum.

Kidneys and ureters

The specific gastrointestinal structures mentioned that transition from being suspended to being fixed against the posterior wall.

Parts of the small and large intestines

The structures associated with the posterior abdominal wall along the body's median axis

Large vessels, nerves, and lymphatics

The mesentery supporting the developing gut tube during development

Dorsal mesentery

1)The superior aperture of the abdomen; 2) the structure closing the 1st term

Inferior thoracic aperture; Diaphragm

The margin of the inferior thoracic aperture consists of:

vertebra TXII rib XII, distal end of rib XI, costal margin, and xiphoid process.

The musculotendinous structure separating the thorax from the abdomen

Diaphragm

The muscular extension anchoring each side of the diaphragm to the vertebral column

Crus

The right diaphragmatic crus extends inferiorly to approximately which vertebral level?

LIII

The left diaphragmatic crus extends inferiorly to approximately which vertebral level?

LII

The arch-shaped ligaments anchoring the diaphragm posteriorly

Arcuate ligaments

The arcuate ligament crossing the psoas major muscle

Medial arcuate ligament

The arcuate ligament crossing the quadratus lumborum muscle

Lateral arcuate ligament

The ligament that crosses the aorta and is continuous with both crura

Median arcuate ligament

The vertebral attachment of the medial arcuate ligament

Transverse process of LI

The bony attachment of the lateral arcuate ligament

Rib XII

The boundary where the abdominal wall becomes continuous with the pelvic wall and the opening through which the abdominal cavity communicates with the pelvic cavity

Pelvic inlet

The posterior bony boundary of the pelvic inlet

Sacrum

The anterior bony boundary of the pelvic inlet

Pubic symphysis

The lateral boundaries of the pelvic inlet

Distinct bony rims of the pelvic bones

The structure separating the abdomen from the thorax

Diaphragm

The opening that connects the abdomen directly to the pelvis, serving as the passageway for structures moving between the two cavities.

Pelvic inlet

The membrane continuous between the abdominal and pelvic cavities

Peritoneum

The pelvic organ that can expand superiorly into the abdominal cavity

Bladder

The reproductive organ that can expand superiorly into the abdominal cavity during pregnancy

Uterus

The structure marking the inferior abdominal-wall margin at the abdomen-thigh aperture

Inguinal ligament

The major vascular structures passing between the abdomen and thigh

Major artery and vein of the lower limb

The nerve passing through the abdomen-thigh aperture and innervating the quadriceps femoris

Femoral nerve

The major action of the quadriceps femoris muscle

Knee extension

The non-neural, nonvascular structures also passing between abdomen and thigh

Lymphatics and distal psoas major and iliacus

The action of psoas major and iliacus at the hip joint

Flexion of the thigh at the hip joint

The abdominal artery and vein that become the femoral artery and vein below the inguinal ligament

External iliac artery and vein of the abdomen

The thigh vessels formed when the external iliac vessels pass inferior to the inguinal ligament

Femoral artery and femoral vein of the thigh

The gastrointestinal tube suspended by both ventral and dorsal mesenteries

Foregut

The primitive gut tube regions

Foregut, midgut, and hindgut

The abdominal derivatives of the foregut

Distal esophagus, stomach, and proximal duodenum

The only gut region suspended by both ventral and dorsal mesenteries

Foregut

The foregut diverticulum that grows into the ventral mesentery, giving rise to the liver and gallbladder, and, ultimately to the ventral part of the pancreas

Anterior foregut diverticulum

The direction in which the developing stomach rotates

Clockwise

The effect of stomach rotation on the dorsal mesentery

It moves left and greatly expands

The structures that swing right with the duodenum

Dorsal mesentery and appreciable part of the pancreas

The opening created by restriction of the space associated with the expanded dorsal mesentery

Omental/Epiploic foramen

The space posterior to the stomach enclosed by the expanded dorsal mesentery

Omental bursa (Lesser sac)

The larger part of the peritoneal cavity surrounding the lesser sac

Greater sac

The route providing access from the greater sac to the omental bursa

Omental foramen

The dorsal mesentery portion that greatly enlarges inferiorly and forms an apron-like structure

Greater omentum

The stomach attachment of the greater omentum

Greater curvature of the stomach

The first structure observed when the abdominal cavity is opened anteriorly

Greater omentum

The gastrointestinal structures derived from the midgut

Distal duodenum, jejunum, ileum, ascending colon, and proximal two-thirds of transverse colon

The embryonic structure projecting anteriorly from the developing midgut into the umbilicus

Small Yolk sac

The event caused by rapid gastrointestinal growth in which the midgut loop leaves the abdominal cavity

Midgut herniation

The direction of rotation of the two limbs of the midgut loop

Counterclockwise

The portion of the midgut loop that descends into the inferior right abdomen

Cecum

The artery located at the center of the midgut rotation axis which supplies the midgut

Superior mesenteric artery

The mesentery suspending the transverse colon

Transverse mesocolon

The structure that hangs over the transverse colon and mesocolon

Greater omentum

The hindgut derivatives in the abdomen

Distal one-third of transverse colon, descending colon, sigmoid colon, and superior rectum

The structures formed as proximal hindgut parts swing left

Descending colon and sigmoid colon

The route taken by the sigmoid colon before becoming continuous with the rectum

Through the pelvic inlet

The vertebral level where the sigmoid colon becomes continuous with the rectum

Vertebra level SIII

The thoracic spinal nerves whose anterior rami enter the abdominal wall

T7 to T12

The intercostal nerves supplying abdominal-wall skin and muscle

T7 to T11