Sphincters

Question 1

What are the sphincters of the GI tract?

Answer 1

Upper oesophageal

Lower oesophageal

Pyloric

Sphincter of Oddi

Ileo-caecal

Internal anal

External anal

Question 2

What are most of the sphincters of the GI tract made up of?

Answer 2

Thickenings of smooth muscle in wall

circular smooth muscle

Question 3

What is the external anal sphincter made up of?

Answer 3

Skeletal muscle

Question 4

How are the sphincters of the GI tract controlled?

Answer 4

Neural control

• autonomic
• enteric
• somatic

Question 5

Which sphincter of the GI tract is under somatic nervous system control?

Answer 5

External anal sphincter

Question 6

Is the external anal sphincter under voluntary or involuntary control?

Answer 6

Voluntary

Question 7

What are the functions of sphincters in the GI tract?

Answer 7

Divide the GI tract into different parts with different functions

Control movement of contents along the GI tract

Prevent reflux of contents in the GI tract