Through which structure does blood flow from the heart to the lungs in the pulmonary circulation?

Choice A reason: Memory loss is not typically associated with vitamin C deficiency. Memory loss can be related to various conditions, including neurological disorders or vitamin B12 deficiency.

Choice B reason: Brittle hair can be a sign of vitamin C deficiency due to its role in collagen production, which affects the health of hair. However, it is not as specific or common as bleeding gums.

Choice C reason: Bleeding gums are a common symptom of vitamin C deficiency. Vitamin C is essential for the maintenance of healthy connective tissue, which includes the gums. A deficiency can lead to scurvy, which manifests as bleeding gums among other symptoms.

Choice D reason: Constipation is not directly associated with vitamin C deficiency. While a healthy diet rich in vitamin C can aid digestion, constipation can be caused by a variety of factors unrelated to vitamin C intake.

Choice A reason: An upper GI endoscopy is typically performed to evaluate symptoms of persistent heartburn, as it allows direct visualization of the esophagus, stomach, and duodenum, which are commonly affected by conditions that cause heartburn.

Choice B reason: Flexible sigmoidoscopy is used to examine the lower part of the colon, which is not typically
associated with symptoms of heartburn.

Choice C reason: A colonoscopy is used to view the entire colon and is not the first choice for investigating heartburn,
as this symptom is not directly related to the colon.

Choice D reason: A lower GI series, or barium enema, is an X-ray examination of the large intestine, which includes the colon and rectum. It is not typically used to diagnose conditions that cause heartburn.