Houston valve
Overview
|
WikiDoc Resources for Houston valve |
|
Articles |
|---|
|
Most recent articles on Houston valve Most cited articles on Houston valve |
|
Media |
|
Powerpoint slides on Houston valve |
|
Evidence Based Medicine |
|
Clinical Trials |
|
Ongoing Trials on Houston valve at Clinical Trials.gov Trial results on Houston valve Clinical Trials on Houston valve at Google
|
|
Guidelines / Policies / Govt |
|
US National Guidelines Clearinghouse on Houston valve NICE Guidance on Houston valve
|
|
Books |
|
News |
|
Commentary |
|
Definitions |
|
Patient Resources / Community |
|
Patient resources on Houston valve Discussion groups on Houston valve Patient Handouts on Houston valve Directions to Hospitals Treating Houston valve Risk calculators and risk factors for Houston valve
|
|
Healthcare Provider Resources |
|
Causes & Risk Factors for Houston valve |
|
Continuing Medical Education (CME) |
|
International |
|
|
|
Business |
|
Experimental / Informatics |
Although the term rectum means straight, the human rectum is not. There are certain permanent transverse folds, of a semilunar shape, known as Houston’s valves (or transverse folds of rectum). They project into the lumen of the rectum.
These folds are about 12 mm. in width, and contain some of the circular fibers of the gut.
In the empty state of the intestine they overlap each other, as Houston remarks, so effectually as to require considerable maneuvering to conduct a bougie or the finger along the canal.
Their use seems to be, to support the weight of fecal matter, and prevent its urging toward the anus, where its presence always excites a sensation demanding its discharge.
They are formed from circular muscle coat of the rectal wall.
Details on each fold
They are usually three in number; sometimes a fourth is found, and occasionally only two are present.
- One is situated near the commencement of the rectum, on the right side.
- A second extends inward from the left side of the tube, opposite the middle of the sacrum.
- A third, the largest and most constant, projects backward from the forepart of the rectum, opposite the fundus of the urinary bladder.
- When a fourth is present, it is situated nearly 2.5 cm. above the anus on the left and posterior wall of the tube.
Clinical significance
During sigmoidoscopy and colonoscopy the scope is moved around to negotiate these folds.
External links
- Shafik A, Doss S, Ali Y, Shafik A (2001). "Transverse folds of rectum: anatomic study and clinical implications". Clin Anat. 14 (3): 196–203. PMID 11301467.