41) What are the chemical messengers that trigger a physiological response, secreted from many glands of the body?

A) hormones

B) tissues

C) minerals

D) organelles

42) Mechanical digestion begins in the

A) mouth.

B) stomach.

C) small intestine.

D) large intestine.

43) Carbohydrate digestion begins in the

A) mouth.

B) stomach.

C) small intestine.

D) large intestine.

44) Once food is swallowed, what is the tiny flap of tissue that keeps food from entering the trachea called?

A) pyloric valve

B) esophagus

C) epiglottis

D) upper esophageal sphincter

45) The wavelike contractions that move food along the GI tract are called

A) chime.

B) peristalsis.

C) lymph.

D) diarrhea.

46) The structure of the brush border aids digestion by

A) increasing the small intestine’s absorptive capacity.

B) increasing the large intestine’s absorptive capacity.

C) releasing bile quickly into the duodenum.

D) mechanically breaking down food.

47) The small intestine is described as “small” because

A) it is the shortest part of the gastrointestinal tract.

B) it consists of only one section.

C) not much digestion or absorption occurs there.

D) it is only an inch in diameter.

48) Inside each villus of the small intestine are capillaries and a small lymph vessel called a(n)

A) lacteal.

B) gluteal.

C) chyme.

D) organelle.

49) A painful sensation in the chest that results from gastric juices seeping back up into the esophagus is called

A) celiac disease.

B) irritable bowel syndrome (IBS).

C) gastroesophageal reflux (GER).

D) peptic ulcer.

50) Which component of the large intestine helps to synthesize certain vitamins?

A) glucagon

B) insulin

C) gastric juice

D) intestinal flora