How many Houston valves are there?
Besides these there are certain permanent transverse folds, of a semilunar shape, known as the transverse folds of rectum (Houston’s valves). They are usually three in number; sometimes a fourth is found, and occasionally only two are present.
Where are the valves of Houston?
rectum
The transverse folds of rectum (or Houston’s valves or the valves of Houston) are semi-lunar transverse folds of the rectal wall that protrude into the rectum, not the anal canal as that lies below the rectum.
What do the valves of Houston do?
…by permanent transverse folds (valves of Houston) that help to support the rectal contents. A sheath of longitudinal muscle surrounds the outside wall of the rectum, making it possible for the rectum to shorten in length.
Where are the spiral valves of Heister located?
cystic duct
Heister valves, also known as spiral valves, are mucosal folds located on the endoluminal surface of the cystic duct (CD).
How many folds does the rectum have?
The rectum contains three folds, namely the valves of Houston. The superior (at 10 cm to 12 cm) and inferior (at 4 cm to 7 cm) folds are located on the left side and the middle fold (at 8 cm to 10 cm) is located at the right side.
What is the function of Denonvilliers fascia?
Anatomical terminology The rectoprostatic fascia (Denonvilliers’ fascia) is a membranous partition at the lowest part of the rectovesical pouch. It separates the prostate and urinary bladder from the rectum.
Is fascia of Denonvilliers in female?
The original description of the fascia was based exclusively on findings observed in 12 male cadavers, although Denonvilliers gave no account of its existence in women.
What is controlled by the spiral valve of Heister?
The spiral valves of Heister are supported by underlying smooth muscle fibers. There is some uncertainty regarding the role of the folds. Historically, physicians believed that their function was to aid in the passage of bile to and from the gallbladder, as well as regulate the degree of gallbladder distension.
What are the spiral valves of Heister?
Heister valves, also known as spiral valves, are mucosal folds located on the endoluminal surface of the cystic duct (CD). They were described by Lorenz Heister in 1732,1 who attributed a valvular function to them.
What part of the colon is at 70 cm?
sigmoid colon
The sigmoid colon length can vary considerably, ranging from 40 to 70 cm when stretched during scope insertion and crumple down to only 30–35 cm when the scope is straightened fully. This makes precise anatomical location within the sigmoid by virtue of distance on insertion unreliable.