A 48-year-old female is admitted to the hospital with a distended abdomen. A CT scan examination provides evidence of the presence of ascites. In which of the following locations will an ultrasound machine most likely confirm the presence of the ascitic fluid with the patient in the supine position?

(b) Source: GAS 307; GA 144 In a supine patient, fluid accumulation will often occur in the pouch of Morison, which is the lowest space in the body in a supine position. The hepatorenal space is located behind the liver and in front of the parietal peritoneum covering the right kidney. The vesicouterine and rectouterine spaces are also potential areas of fluid accumulation; however, fluid accumulation in these spaces occurs when the patient is in an erect position rather than a supine position.