The primary function of which organ is to deliver chyme (food bolus) to the duodenum at the proper rate?

A. Incontinence: Incontinence can occur in many older adults even without UTI and is not unique or diagnostic of infection.

B. Low back pain: Low back pain can occur with pyelonephritis, but it is not specific to older adults and not the most distinctive symptom in this population.

C. Urinary retention: Retention is possible, but confusion is more commonly seen as an atypical presentation of infection in older adults.

D. Confusion: Older adults often present with confusion, delirium, or change in mental status as a primary symptom of UTI, rather than localized symptoms.

A. Nothing, it's just a pass through to the next structure: The stomach plays a critical role in digestion through mixing and secretion of gastric juices.

B. Gastric juices mix with the food and the stomach muscles squeeze it: This process forms chyme through mechanical (squeezing) and chemical (acid/enzymes) digestion.

C. The food moves quickly into the small intestine: Food stays in the stomach for a period of time for processing before gradually passing into the small intestine.

D. The food is completely digested and is absorbed by tiny blood vessels in the walls of the stomach: Most digestion and nutrient absorption occur in the small intestine, not the stomach.