What are the effect of torsion to Gastropoda?
What are the effect of torsion to Gastropoda?
This brings the mantle cavity and anus to an anterior position above the head. Torsion has a number of anatomical effects in the adult gastropod: the mantle cavity lies anteriorly and dorsally, the nerve cords between the cerebral and visceral ganglia are crossed, and the gut is twisted into a loop.
Is torsion in gastropods clockwise or anticlockwise?
Torsion is a process in larval gastropods whereby the visceropallium is rotated anti- clockwise through 180° from its initial position on the head-foot complex.
What is endoscopic Detorsion?
• Emergency endoscopic decompression, detorsion and reduction (EDDR) aims to decompress the dilated colon and untwist the volvulus. EDDR is the treatment of choice in uncomplicated patients. ○ The patients should not have signs of peritonitis.
How do you do Detorsion?
With torsion of the left testis, hold the testicle with the right thumb and forefinger and then rotate the testicle clockwise 180 degrees. This manipulation may need to be repeated 2-3 times, because testicular torsion may involve rotations of 180-720 degrees.
What is colonoscopic Detorsion?
Purpose: Colonoscopic detorsion (CD) is the first treatment option for uncomplicated sigmoid volvulus (SV). We aim to examine the factors affecting the failure of CD. Methods: The files of patients, treated after diagnosis of SV between January 2015 and September 2020, were retrospectively reviewed.
What is Detorsion of volvulus?
Emergency endoscopic decompression, detorsion and reduction (EDDR) aims to decompress the dilated colon and untwist the volvulus. EDDR is the treatment of choice in uncomplicated patients.
What is torsion (gastropod)?
Torsion (gastropod) In some groups of gastropods ( Opisthobranchia) there is a degree of secondary detorsion or rotation towards the original position; this may be only partial detorsion or full detorsion. The torsion or twisting of the visceral mass of larval gastropods is not the same thing as the spiral coiling of the shell,…
What is detorsion in Gastropoda?
Detorsion in Gastropoda: In some forms the changes brought about by torsion are reversed to a certain extent, while in others, e.g., Aplysia a complete reversal of torsion takes place which is known as detorsion, this occurs when the shell is lost or much reduced, the ctenidia liberated from their enclosing case point posteriorly again,
What is the difference between torsion and detorsion?
Torsion allows foot to be retracted after the head for better protection of head. DETORSION Detorsion is reversal of torsion which takes place when during evolution shell is lost or a type of shell evolves that has openings on the opposite sides.
What is the significance of torsion in the evolution of larva?
He suggested that before torsion the untwisted larva swimming the sea was subjected as an easy prey to its predators because the mantle cavity was at the posterior position and there is no place into which delicate head and velum can be withdrawn at the time of danger so it is disadvantageous to the larval life.