Discuss the act of defecation and the nerve innervation involved; actions of the internal and external sphincters and hemorrhoids.

Answered: Discuss the act of defecation and the…

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

See similar textbooks

Related questions

Question

Discuss the act of defecation and the nerve innervation involved; actions of the internal and external sphincters and hemorrhoids.

Expert Solution

Step 1

1. The large intestine is the last part of gastrointestinal tract, which is larger in diameter than the small intestine. It does not produce any digestive enzymes, but absorbs water, salts, and some vitamins. It also stores indigestible materials until it is eliminated of feces from the anus. The last section of large intestine is called rectum. The terminal part of rectum is called anal canal. The opening of the anal canal to the exterior, called the anus, is guarded by an internal anal sphincter of smooth involuntary muscle and an external anal sphincter of skeletal voluntary muscle. Normally these sphincters keep the anus closed except during defecation.