Exam | Portage Learning |Q&A | 26/27 Edition
(PDF)
1. Which type of signaling occurs when a hormone exerts an action on the same cell that produced it?
A) Paracrine signaling
B) Autocrine signaling
C) Endocrine signaling
D) Neuroendocrine signaling
Correct Answer: Autocrine signaling
Rationale: Autocrine signaling occurs when a hormone or chemical messenger acts on the same cell that
produced it. Paracrine signaling acts on nearby cells, and endocrine signaling involves hormones
traveling through the bloodstream to distant target cells.
2. What is the classic definition of an endocrine hormone?
A) A hormone that acts locally on neighboring cells
B) A hormone that acts on the same cell that produced it
C) A hormone released into circulation to act on a distant target organ
D) A hormone that travels through a neural synapse
Correct Answer: A hormone released into circulation to act on a distant target organ
Rationale: Endocrine signaling involves hormones being released into the bloodstream to exert effects
on target organs at a distance. This distinguishes it from paracrine (local) and autocrine (same cell)
signaling.
3. Which of the following is NOT a hormone produced by the anterior pituitary?
A) Growth hormone (GH)
,B) Adrenocorticotropic hormone (ACTH)
C) Antidiuretic hormone (ADH)
D) Thyroid-stimulating hormone (TSH)
Correct Answer: Antidiuretic hormone (ADH)
Rationale: ADH is synthesized by the hypothalamus and released from the posterior pituitary. The
anterior pituitary produces GH, ACTH, TSH, FSH, LH, and prolactin.
4. Which hormones are released by the posterior pituitary?
A) GH and ACTH
B) TSH and Prolactin
C) ADH and Oxytocin
D) FSH and LH
Correct Answer: ADH and Oxytocin
Rationale: The posterior pituitary stores and releases ADH (antidiuretic hormone) and oxytocin, which
are synthesized in the hypothalamus. All other hormones listed are released from the anterior pituitary.
5. What is the primary function of the hypothalamus in the endocrine system?
A) To secrete hormones directly into the bloodstream
B) To link the nervous system to the endocrine system and regulate homeostasis
C) To produce all hormones for the body
D) To store hormones for later release
Correct Answer: To link the nervous system to the endocrine system and regulate homeostasis
, Rationale: The hypothalamus serves to link the nervous system to the endocrine system by producing
releasing hormones that stimulate the pituitary. It regulates homeostasis, body temperature, hunger,
behavior, and emotion.
6. Why is the pituitary gland often referred to as the "master gland"?
A) It is the largest endocrine gland
B) It produces all hormones in the body
C) It stimulates target organs to secrete their hormones
D) It is located at the base of the brain
Correct Answer: It stimulates target organs to secrete their hormones
Rationale: The pituitary gland is known as the "master gland" because it secretes stimulating hormones
that regulate the activity of other endocrine glands. It does not produce all hormones, but it controls
many other glands.
7. How does negative feedback maintain hormonal homeostasis?
A) By enhancing the release of a hormone once a set point is reached
B) By preventing over-secretion of a hormone once optimal levels are achieved
C) By having no effect on hormone secretion
D) By stimulating the pituitary to release more hormones
Correct Answer: By preventing over-secretion of a hormone once optimal levels are achieved
Rationale: Negative feedback maintains homeostasis by inhibiting further hormone release once optimal
levels are achieved. This prevents over-secretion and keeps hormone levels within a normal range.
8. Which of the following is an example of positive feedback?
A) The action of ADH diluting the blood
B) The release of TSH stimulating the thyroid