What is the interrelated network of nerves within the gastrointestinal wall that regulates its muscular action known as?

Correct Answer: C

Rationale: The correct answer is C, intramural nerve plexus. The intramural nerve plexus is the interrelated network of nerves within the gastrointestinal wall that regulates its muscular action. The gastric nerve plexus (choice A) specifically pertains to the network of nerves in the stomach, not the entire gastrointestinal wall. The biliary nerve plexus (choice B) is associated with nerve supply in the liver, gallbladder, and bile ducts, not the gastrointestinal wall. The intestinal nerve plexus (choice D) is a general term that may refer to various nerve networks within the intestines but does not specifically address the entire gastrointestinal wall.

Correct Answer: D

Rationale: The correct answer is choice D because medication for high cholesterol is typically not considered unless Therapeutic Lifestyle Changes (TLC), which include diet and exercise, have not proven effective after a three-month period. This approach ensures that lifestyle modifications are given a fair chance to lower cholesterol levels before resorting to medication. Choice A is incorrect because the number of risk factors for coronary heart disease does not dictate when to begin medication; it is about the effectiveness of lifestyle changes. Choice B is incorrect as the duration of coronary heart disease symptoms does not determine when to start medication; the focus is on the response to TLC. Choice C is incorrect because the coverage of prescription drugs by the patient's insurance does not influence the medical decision to use medication for high cholesterol; it is based on medical necessity and effectiveness of prior interventions.

Correct Answer: B

Rationale: Beta cells in the islets of Langerhans in the pancreas are responsible for the production and secretion of insulin, which is crucial for regulating blood glucose levels. Alpha cells, on the other hand, produce glucagon, a hormone that raises blood glucose levels. Gamma cells and Delta cells do not exist in the islets of Langerhans; therefore, they are incorrect choices.

Correct Answer: B

Rationale: Malnutrition is a common comorbidity in patients with Chronic Kidney Disease (CKD). This is mainly due to factors such as dietary restrictions, poor appetite, and the body's increased nutritional needs as it struggles to deal with the disease. Liver disease (Choice A) is not typically associated directly with CKD, although both conditions may coexist in some patients. Acute renal failure (Choice C) is not a comorbidity but a severe and potentially lethal progression of CKD. Difficulty breathing (Choice D) is not a comorbidity but can be a symptom of severe kidney disease or other underlying conditions. However, malnutrition is more commonly observed in CKD patients compared to difficulty breathing.

Correct Answer: B

Rationale: The correct answer is B. The classification of the 20 common amino acids is not based on the properties of their side chains, but rather on the structure of their amino and carboxyl groups. These groups are consistent among all amino acids, while the side chains, also known as R groups, are what vary and give each amino acid its unique properties. Choice A is correct because proteins are indeed composed of amino acids. Choice C is incorrect because while the side chains of amino acids can vary, the general structure of an amino acid - a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a side chain - is consistent. Choice D is correct because amino acids do polymerize to form long chains called polypeptides, which can then fold into complex shapes to form proteins.