Keep it moving!
What wave-like muscular process propels food through the alimentary canal?
Peristalsis
Which gastric cells secrete pepsinogen?
Chief cells
• Parietal cells secrete hydrochloric acid (HCl) and intrinsic factor (which is necessary for the absorption of vitamin B12 in the small intestine).
• Chief cells secrete pepsinogen (the inactive precursor to the protein-digesting enzyme pepsin) and gastric lipase (an enzyme that helps digest lipids).
You smell pizza, and your stomach begins increasing secretion before you eat. Which gastric secretion phase is this?
Cephalic phase
What tiny air sacs are the main sites of gas exchange in the lungs?
Alveoli
Intestinal contents need to be mixed rather than pushed forward. Which movement accomplishes this?
Segmentation
Which gastric cells produce hydrochloric acid AND intrinsic factor?
Parietal cells
Food enters and stretches your stomach, stimulating reflexes that increase secretion. Which phase is this?
Gastric phase
Put these airway structures in order as inhaled air moves inward: bronchi, nasal cavity, trachea, pharynx, larynx.
Nasal cavity → pharynx → larynx → trachea → bronchi.
Chyme is ready to leave the stomach. Which sphincter controls its passage into the duodenum?
Pyloric sphincter
Complete this activation sequence: Pepsinogen is inactive. With help from stomach acid, it becomes _____, which digests _____
Pepsin; proteins
Partially digested proteins stimulate G cells. Which hormone do these cells release, and does it stimulate or inhibit gastric secretion?
Gastrin; it stimulates gastrin secretion
At the lungs, which direction does each gas move: oxygen and carbon dioxide?
O₂: alveoli → blood. CO₂: blood → alveoli.
A student says, “All three phases of swallowing are voluntary.” Which phase actually is voluntary?
The oral/buccal (cheek) phase. The pharyngeal and esophageal phases are involuntary.
A person’s stomach stops producing intrinsic factor. Absorption of which vitamin would be impaired?
Vitamin B12
Stomach contents become very acidic. Which inhibitory messenger helps reduce further gastric secretion?
Somatostatin-- remember from the endocrine system? Also called Growth hormone-inhibiting hormone (GHIH), it's a crucial inhibitory peptide hormone that puts the brakes on various hormone secretions, cell growth, and gut activity across the body.
During exercise, muscles become warmer and produce more CO₂ and H⁺. Which way does the oxygen-Hb curve shift, and does oxygen unloading increase or decrease?
Right shift; oxygen unloading increases.
Put these six structures in the order food travels: stomach, large intestine, pharynx, oral cavity, small intestine, esophagus.
Oral cavity → pharynx → esophagus → stomach → small intestine → large intestine.
A proton pump inhibitor blocks the H⁺/K⁺ pump in parietal cells. What happens to H⁺ secretion into the stomach and stomach acidity?
H⁺ secretion decreases, so the stomach becomes less acidic—its pH rises.
Acidic, fatty chyme enters the duodenum. After the brief initial stimulation, should gastric secretion and motility increase or decrease—and what purpose does this serve?
Both decrease. This slows delivery so the duodenum can process the chyme already present.
Someone hypoventilates while tissue CO₂ production stays the same. Predict the changes in blood CO₂, H⁺, and pH.
CO₂ increases → H⁺ increases → pH decreases.