The last part of the digestive tract is the anal canal, which is about 2-3 centimeters long. The anus is actually the opening of the anal canal to the outside.
The anal canal has two muscles: the internal anal sphincter and the external anal sphincter. The internal anal sphincter is made up of smooth muscles, which cannot be controlled or contracted voluntarily. On the other hand, the external anal sphincter is made of skeletal muscles and can be controlled, that is, it can be voluntarily contracted.
Suggested Readings
Source:
Seeley, R. et al: ESSENTIALS OF ANATOMY AND PHYSIOLOGY. 5th ed. McGraw – Hill, 2005.
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The anal canal has two muscles: the internal anal sphincter and the external anal sphincter. The internal anal sphincter is made up of smooth muscles, which cannot be controlled or contracted voluntarily. On the other hand, the external anal sphincter is made of skeletal muscles and can be controlled, that is, it can be voluntarily contracted.
Suggested Readings
Source:
Seeley, R. et al: ESSENTIALS OF ANATOMY AND PHYSIOLOGY. 5th ed. McGraw – Hill, 2005.
[Top of Page]
