DIGESTIVE SYSTEM: Introduction & Anatomy

Which function of the digestive system involves rhythmic contractions that move food along the gastrointestinal tract?

• Ingestion

• Secretion

• Mixing and propulsion (peristalsis)

• Absorption

Fill in the blank with the precise structure: The sphincter that controls stomach emptying is the (a)   .

Arrange the following structures to represent the correct path of food through the digestive system: Mouth, Esophagus, Stomach, Anus, Pharynx, Small intestine, Large intestine, Rectum.

• Mouth → Pharynx → Esophagus → Stomach → Small intestine → Large intestine → Rectum → Anus

• Mouth → Esophagus → Pharynx → Stomach → Large intestine → Small intestine → Rectum → Anus

• Mouth → Pharynx → Stomach → Esophagus → Small intestine → Rectum → Large intestine → Anus

• Mouth → Pharynx → Esophagus → Stomach → Large intestine → Small intestine → Anus → Rectum

A student proposes that increased circular folds, villi, and microvilli in the small intestine primarily aid secretion. Evaluate this claim and choose the best reasoning.

• Correct, these structures increase the release of digestive enzymes.

• Incorrect, these structures mainly increase surface area for absorption.

• Correct, they protect the intestinal lining from acid.

• Incorrect, they slow peristalsis to allow more mixing.

Recall: Which small intestine region primarily receives enzymes and bile to begin chemical digestion?

• Duodenum

• Jejunum

• Ileum

Recall: Which accessory organ produces bile?

• Liver

• Gallbladder

• Pancreas

Skill/Concept: Which statement best describes the distinct roles of the liver and gallbladder in bile management?

• Both produce and store bile

• The liver stores bile; the gallbladder produces bile

• The liver produces bile; the gallbladder stores and releases bile

• Neither organ is involved with bile

Strategic Thinking: After a large fatty meal, which hormone would best promote digestion by stimulating bile release and pancreatic enzymes, and why? Provide the hormone name and brief reason.

• Cholecystokinin (CCK): It stimulates bile release and pancreatic enzyme secretion.

• Gastrin: It mainly stimulates gastric acid secretion.

• Secretin: It primarily stimulates bicarbonate secretion from the pancreas.

• Insulin: It regulates blood glucose levels, not digestion of fats.

Recall the major kidney regions. Which list correctly identifies the primary anatomical areas referenced in this lesson?

• Cortex, medulla (pyramids), renal pelvis, hilum

• Cortex, cortex medulla, urethra, papilla

• Medulla, renal cortex, bladder, calyx

• Renal pelvis, ureter, bladder, urethra

Fill in the blank with the next structure in nephron flow: Glomerulus → Bowman’s capsule → PCT → Loop of Henle → DCT → (a)   → Calyx → Renal pelvis → Ureter.