Digestion Unit Exam

Which statement best describes the overall role of the digestive system?

• It oxygenates blood before circulation

• It breaks down food, absorbs nutrients and water, and eliminates solid waste

• It produces hormones to regulate body temperature

• It filters toxins directly from the skin

Saliva primarily begins which process in the mouth?

• Protein digestion by pepsin

• Starch breakdown and moistening of food

• Absorption of amino acids

• Formation of hydrochloric acid

What term describes the soft, moist ball of chewed food formed in the mouth before swallowing?

• Chyme

• Bolus

• Lacteal

• Villus

Salivary amylase acts on which food component?

• Lipids, breaking them into fatty acids

• Proteins, breaking them into amino acids

• Starches, beginning carbohydrate digestion

• Vitamins, activating them for absorption

Which organ is primarily responsible for moving the bolus from the pharynx to the stomach?

• Liver

• Esophagus

• Large intestine

• Gallbladder

As food descends the esophagus, how do the muscle types change?

• They remain entirely skeletal muscle

• They shift from smooth to skeletal muscle

• They shift from skeletal to smooth muscle

• They remain entirely cardiac muscle

What is peristalsis and why is it important?

• A secretion that neutralizes acid; it protects the stomach lining

• A wave-like muscular contraction that propels food through the GI tract

• A hormone that increases appetite; it controls eating behavior

• A type of chewing that occurs only in the mouth

Which list correctly names the four general layers of the GI tract wall from most inner near the lumen to most outer layer?

• Serosa, muscularis externa, submucosa, mucosa

• Mucosa, submucosa, muscularis externa, serosa

• Submucosa, mucosa, serosa, muscularis externa

• Muscularis externa, serosa, mucosa, submucosa

What type of tissue primarily lines the mucosa of the GI tract?

• Epithelial tissue

• Cartilage

• Bone

• Adipose tissue

What is the name of the connective tissue layer found just beneath the epithelial basement membrane of the mucosa?

• Myenteric plexus

• Lamina propria

• Submucosal plexus

• Visceral peritoneum