Which of the following is not a category of endocrine gland stimulus?

Correct Answer: A

Rationale: The correct answer is A: enzyme. Endocrine glands are stimulated by three main categories: humoral (based on blood levels of certain substances), neural (stimulation by nerves), and hormonal (stimulation by other hormones). Enzymes do not directly stimulate endocrine glands. They are biological catalysts that facilitate biochemical reactions, not a category of stimulus for endocrine glands. Therefore, A is the correct answer. Choices B, C, and D are incorrect as they are valid categories of endocrine gland stimulus based on blood levels, nerves, and hormones respectively.

Correct Answer: C

Rationale: The correct answer is C: epinephrine. Steroid-based hormones are derived from cholesterol and include estrogen, aldosterone, and cortisone. Epinephrine is a catecholamine hormone, not a steroid hormone. Catecholamines are derived from the amino acid tyrosine, not cholesterol like steroid hormones. Therefore, epinephrine does not belong to the category of steroid-based hormones.

Correct Answer: A

Rationale: The correct answer is A: liver. Thyroid hormone affects the liver by regulating metabolism and energy production. It increases the breakdown of fats, proteins, and carbohydrates. The liver plays a crucial role in converting thyroid hormones into their active form. Summary: B: The spleen is not directly affected by thyroid hormone. C: The thyroid gland produces thyroid hormone but is not directly affected by it in adults. D: While the brain is indirectly influenced by thyroid hormone, it is not a primary target organ for its effects in adults.

Correct Answer: B

Rationale: The correct answer is B: hormonal, humoral, and neural. Hormonal regulation involves feedback loops where hormone levels control their own production. Humoral regulation involves substances in body fluids influencing hormone release. Neural regulation involves the nervous system influencing hormone production. Option A is incorrect because sensory mechanisms do not directly control hormone production. Option C is incorrect because sensory mechanisms are not typically involved in hormone regulation. Option D is incorrect because hormonal control is a key mechanism that was omitted.

Correct Answer: C

Rationale: The correct answer is C: growth hormone and LH. The anterior pituitary gland secretes these hormones. Growth hormone regulates growth, metabolism, and body composition, while LH (luteinizing hormone) plays a role in reproductive function. A: Anti-diuretic hormone and oxytocin are produced by the posterior pituitary gland. B: ACTH (adrenocorticotropic hormone) is secreted by the anterior pituitary, but insulin is produced by the pancreas. D: Thyroxine is released by the thyroid gland, and cortisol is produced by the adrenal glands, not the anterior pituitary.