Label the digestive system structures in the following figure. a. ___b. ___c. ___d. ___e. ___f. ___g. ___h. ___i. ___j. ___k.___

Which is more essential to life and why: chemical digestion or mechanical digestion?

Which of the following are true for digestion:

I. Chemical digestion begins in the stomach.

II. Digestion involves breaking down food both physically and chemically.

III. Mechanical digestion increases the surface area of ingested food.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. The muscularis externa of most of the alimentary canal consists of inner circular and outer longitudinal layers of smooth muscle.