Question

Infants do not develop voluntary control of which of the following sphincter of the alimentary canal? (It is developed only when they grow up)

• A. Internal anal sphincter
• B. Pyrolic sphincter
• C. External anal sphincter
• D. All of the above

Answer 1

The correct option is C External anal sphincter

The external anal sphincter is an elliptical shape is a flat plane of muscular fibres which is adherent to the skin surrounding the margin of the anus. It is absent in infants that is why they are not able to control the defaecation as it is only present in grown-ups which control their bowel movement.

So the correct option is 'External anal sphincter'