The haustra (: haustrum) of the
colon are the small pouches caused by sacculation (sac formation), which give the colon its segmented appearance. The
teniae coli run the length of the colon. A proposed explanation for the existence of haustra is that the colon becomes sacculated between the teniae coli because the taenia coli are shorter than the colon. However, it is now more commonly accepted that the haustra form because of
enteric nervous system activity.
Haustral contractions are slow segmenting, uncoordinated movements that occur approximately every 25 minutes. One haustrum distends as it fills with
chyme
Chyme or chymus (; ) is the semi-fluid mass of partly digested food that is expelled by the stomach, through the pyloric valve, into the duodenum (the beginning of the small intestine).
Chyme results from the mechanical and chemical breakdown ...
, which stimulates muscles to contract, pushing the contents to the next haustrum. Also see
peristalsis
Peristalsis ( , ) is a type of intestinal motility, characterized by symmetry in biology#Radial symmetry, radially symmetrical contraction and relaxation of muscles that propagate in a wave down a tube, in an wikt:anterograde, anterograde dir ...
.
There is a wider distance between haustra than between the
circular folds
The circular folds (also known as valves of Kerckring, valves of Kerchkring, plicae circulares, ''plicae circulae'', and ''valvulae conniventes'') are large valvular flaps projecting into the lumen of the small intestine.
Structure
The entire s ...
of the
small intestine
The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...
, and the haustra do not reach around the entire circumference of the intestine, in contrast to circular folds of the small intestine that do. These differences can assist in distinguishing the small intestine from the colon on an
abdominal x-ray
An abdominal x-ray is an x-ray of the abdomen. It is sometimes abbreviated to AXR, or KUB (for kidneys, ureters, and urinary bladder).
Indications
In adults, abdominal X-rays have a very low specificity and cannot rule out suspected obstructi ...
.
Clinical significance
Widespread loss of haustra is a sign of chronic
ulcerative colitis
Ulcerative colitis (UC) is one of the two types of inflammatory bowel disease (IBD), with the other type being Crohn's disease. It is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary sympto ...
.
Localized ahaustral distended colon can be seen on
abdominal x-ray
An abdominal x-ray is an x-ray of the abdomen. It is sometimes abbreviated to AXR, or KUB (for kidneys, ureters, and urinary bladder).
Indications
In adults, abdominal X-rays have a very low specificity and cannot rule out suspected obstructi ...
during obstruction or
volvulus.
Sigmoidal volvolus, more often seen in psychiatric and neurologically impaired patients (e.g.
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
), shows lack of haustra on x-ray and points from the pelvis to the right upper quadrant just below the diaphragm.
References
Further reading
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{{Authority control
Large intestine