Which organ system is primarily responsible for regulating electrolytes?

Correct Answer: B

Rationale: The urinary system, specifically the kidneys, is primarily responsible for regulating electrolytes in the body by filtering and excreting excess electrolytes, such as sodium, potassium, and chloride, through urine. The kidneys play a crucial role in maintaining the body's electrolyte balance, which is essential for various bodily functions and overall health. The endocrine system regulates hormones, the lymphatic system is involved in immunity, and the nervous system controls communication in the body. Therefore, the correct answer is B, the urinary system, as it directly handles electrolyte regulation by adjusting their excretion levels.

Correct Answer: D

Rationale: Scurvy is the correct answer. Scurvy is a condition caused by a deficiency of vitamin C in the diet. Vitamin C is essential for collagen synthesis, and its deficiency leads to symptoms such as weakness, swollen and bleeding gums, joint pain, fatigue, and easy bruising. If left untreated, scurvy can lead to more severe complications. Choices A, B, and C are incorrect. Kwashiorkor is a severe form of malnutrition due to insufficient protein intake, pellagra is caused by a deficiency of niacin (vitamin B3), and rickets results from a deficiency of vitamin D, calcium, or phosphate.

Correct Answer: A

Rationale: The muscular system and the skeletal system collaborate to facilitate movement. Muscles are connected to bones through tendons and contract to generate movement at the joints. When muscles contract, they exert force on the bones, resulting in actions like bending the arm or leg. This coordinated effort between muscles and bones is crucial for various activities such as walking, running, and grasping objects. Choices B, C, and D are incorrect because they do not accurately describe the interaction between the muscular and skeletal systems. The skeletal system's primary role is to provide structural support and protect internal organs, while cardiac muscles are responsible for heart function and not bone strength. Smooth muscles are found in internal organs and are not involved in leaching excess minerals from bones.

Correct Answer: B

Rationale: Thyrotropin-releasing hormone (TRH) is not produced by the pituitary gland. TRH is actually produced by the hypothalamus and acts on the pituitary gland to stimulate the release of thyroid-stimulating hormone (TSH). On the other hand, FSH (follicle-stimulating hormone), LH (luteinizing hormone), and ADH (antidiuretic hormone) are all hormones directly produced by the pituitary gland.

Correct Answer: C

Rationale: The correct answer is 'C: anterior.' The term 'anterior' refers to a position in front of or toward the front of the body. In this case, the ribs are positioned in front of the lungs when considering the anatomical position. The term 'medial' means toward the midline of the body, 'superior' means above or higher in position, and 'deep' refers to a position farther from the surface or external part. Therefore, the most appropriate choice is 'anterior' when describing the relationship between the ribs and the lungs.