23. The Digestive System

Label the digestive system structures in the following figure.

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a. ___

b. ___

c. ___

d. ___

e. ___

f. ___

g. ___

h. ___

i. ___

j. ___

k.___

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

The digestive juice product containing enzymes capable of digesting all four major foodstuff categories is:

a. Pancreatic

b. Gastric

c. Salivary

d. Biliary

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.

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

True or False: if false, choose the answer that best corrects the statement.

While the accessory organs contribute important digestive enzymes and fluids, all digestions and absorption of nutrients takes place in the alimentary canal/GI tract.

Four organs are listed below. During food’s path through the alimentary canal, the partially digested food passes through the lumen of each of these organs except:

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

The mucosa of the esophagus, pharynx, and oral cavity contains simple squamous epithelium to protect it from abrasion.

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

b. The esophageal and pharyngeal phases of swallowing are mediated by the swallowing reflex of the brainstem and the enteric nervous system.

Make a simple line drawing of the organs of the alimentary canal and label each organ. Then add three labels to your drawing—salivary glands, liver, and pancreas—and use arrows to show where each of these organs empties its secretions into the alimentary canal.

A drop in pH below 4.5 in the duodenum stimulates the secretion of

(a) Secretin

(b) Cholecystokinin

(c) Gastrin

(d) All of these

Double sheets of peritoneum that provide support and stability for the organs of the peritoneal cavity are the

(a) Mediastina

(b) Mucous membranes

(c) Omenta

(d) Mesenteries