ATI RN
Exam Questions on Endocrine System Questions
Question 1 of 5
Androgens are produced by the _______.
Correct Answer: B
Rationale: The correct answer is B: testes. Androgens, such as testosterone, are male sex hormones primarily produced by the testes. The testes contain specialized cells called Leydig cells that secrete androgens. Ovaries (A) produce female sex hormones like estrogen and progesterone. The hypothalamus (C) regulates hormone production through the pituitary gland but does not directly produce androgens. Islets of Langerhans (D) are clusters of cells in the pancreas responsible for producing insulin and glucagon, not androgens.
Question 2 of 5
A 38-year-old man with galactorrhea is treated with bromocriptine, which eliminates the galactorrhea. The basis for the therapeutic action of bromocriptine is that it
Correct Answer: C
Rationale: Step-by-step rationale: 1. Bromocriptine is a dopamine agonist. 2. Dopamine inhibits prolactin release from the anterior pituitary. 3. Galactorrhea is often caused by excess prolactin. 4. By inhibiting prolactin release, bromocriptine reduces prolactin levels and eliminates galactorrhea. Summary: A: Incorrect - Bromocriptine does not antagonize prolactin action. B: Incorrect - Bromocriptine does not enhance prolactin action. D: Incorrect - Prolactin is not released from the hypothalamus.
Question 3 of 5
Oxytocin ________.
Correct Answer: A
Rationale: The correct answer is A because oxytocin release is an example of a positive feedback control mechanism. When oxytocin is released during childbirth, it stimulates contractions, which in turn lead to more oxytocin release, creating a positive feedback loop. This helps in the progression of labor. Choice B is incorrect because oxytocin is a neurohypophyseal hormone, not an adenohypophyseal secretion. Choice C is incorrect as oxytocin's main effects are related to labor, delivery, and lactation, not menstruation. Choice D is incorrect because oxytocin primarily controls uterine contractions during labor and milk ejection during breastfeeding, not milk production itself.
Question 4 of 5
Thyroid hormone (a small iodinated amine) enters target cells in a manner similar to ________.
Correct Answer: B
Rationale: The correct answer is B: steroid hormones, because both diffuse easily into target cells. Thyroid hormone, being a small iodinated amine, can easily pass through the cell membrane and bind to intracellular receptors, similar to steroid hormones. Unlike insulin (choice A), which binds to cell surface receptors, thyroid hormone and steroid hormones enter the cell to exert their effects. Growth hormone (choice C) and glucagon (choice D) do not share the same mechanism of entry into target cells as thyroid hormone, making them incorrect choices.
Question 5 of 5
Regulating hormones from the hypothalamus ________.
Correct Answer: D
Rationale: The correct answer is D because hormones from the hypothalamus first enter the hypophyseal portal system before reaching the pituitary gland. This system allows direct communication between the hypothalamus and the pituitary gland, enabling precise control over hormone release. Choices A, B, and C are incorrect because they do not accurately describe the normal pathway of hormone regulation from the hypothalamus to the pituitary gland. Option A is incorrect as hormones do not travel to the heart before reaching the pituitary. Option B is incorrect because hormones do not enter the hepatic portal system to reach the pituitary. Option C is incorrect as hormones do not travel to the pituitary through arteries.