Question 1

Adrenocorticotropic hormone specifically targets cells producing hormones called glucocorticoids, which stimulates glucocorticoid secretion.

Accepted Answer

Adrenocorticotropic hormone (ACTH) targets cells in the adrenal cortex that produce hormones called glucocorticoids, such as cortisol. It stimulates the secretion of these hormones.

Question 2

What is the hypophyseal portal system?

Accepted Answer

The answer of What is the hypophyseal portal system?...

Question 3

The adrenal gland is firmly attached to the superior border of each kidney by a dense, fibrous capsule; and can be divided structurally and functionally into a superficial cortex and an inner medulla.

Accepted Answer

This is a correct statement. The adrenal gland is indeed attached to the superior border of each kidney by a dense, fibrous capsule, and it has a superficial cortex and an inner medulla that differ structurally and functionally.

Question 4

The C thyrocytes of the thyroid produce the hormone calcitonin.

Accepted Answer

The C thyrocytes of the thyroid gland produce the hormone calcitonin, which plays a role in regulating calcium levels in the body.

Question 5

Parathyroid hormone stimulates calcitriol synthesis in the kidney and is therefore a tropic hormone.

Accepted Answer

Parathyroid hormone (PTH) binds to receptors on cells in the kidney, stimulating the production of calcitriol (active form of vitamin D) from its precursor molecule. This makes PTH a tropic hormone, as it stimulates the production and release of another hormone (calcitriol) from a specific gland (kidney).

Question 6

Hormones influence cellular operations by changing the types, activities, or quantities of key cytoplasmic enzymes.

Accepted Answer

Hormones can affect cellular function by altering the activity of key cytoplasmic enzymes, either by changing their types or quantities. Hormones bind to specific receptors on the surface of cells, triggering intracellular signaling pathways that ultimately lead to changes in enzyme activity and other cellular processes.

Question 7

Melanocyte-stimulating hormone, the only hormone released by the pars intermedia, is secreted by corticotropes only during fetal development, in young children, in pregnant women, and in some disease states.

Accepted Answer

Melanocyte-stimulating hormone (MSH) is indeed the only hormone released by the pars intermedia, but it is not limited to only fetal development, young children, pregnant women, and some disease states. MSH can also be released in response to certain environmental stimuli, such as prolonged exposure to sunlight, and can play a role in regulating pigmentation and other physiological processes.

Question 8

The posterior lobe of the pituitary gland contains the axons and axon terminals of roughly 50,000 hypothalamic neurons whose cell bodies are either in the supra-optic or paraventricular nuclei.

Accepted Answer

This statement is true. The posterior lobe of the pituitary gland receives axons and axon terminals from hypothalamic neurons, specifically from the supra-optic and paraventricular nuclei. This allows for the release of hormones directly into the bloodstream, controlled by the hypothalamus.

Question 9

The synthesis of calcitriol, a steroid hormone secreted by the kidney, is dependent on the availability of a related steroid called cholecalciferol (vitamin D₃), which may be synthesized in the skin or absorbed from the diet.

Accepted Answer

The synthesis of calcitriol is dependent on the availability of cholecalciferol, which can be synthesized in the skin or absorbed from the diet.

Question 10

Calcitonin assists in the regulation of calcium ion concentrations in body fluids, especially during childhood when calcitonin stimulates bone growth and mineral deposition in the skeleton, and under physiological stresses such as starvation or pregnancy.

Accepted Answer

Calcitonin is involved in the regulation of calcium ion concentrations in body fluids and does stimulate bone growth and mineral deposition in the skeleton, especially during childhood. It can also assist in maintaining calcium homeostasis during physiological stresses such as starvation or pregnancy.

Question 11

The types of cells found in the parathyroid gland are the parathyroid cells (productive glandular cells)and the oxyphil cells.

Accepted Answer

The parathyroid gland is composed of two cell types: the parathyroid cells and the oxyphil cells.

Question 12

In the anterior lobe of the pituitary gland, the pars tuberalis, which wraps around the adjacent portion of the infundibulum, represents the major portion of the pituitary gland.

Accepted Answer

The pars tuberalis represents a small portion of the pituitary gland, while the anterior lobe (also known as the adenohypophysis) is the larger portion.

Question 13

The thymus produces thymosin, which is the name originally given to a thymic extract that promoted the development and maturation of lymphocytes and thus increased the effectiveness of the immune system.

Accepted Answer

Thymosin is a hormone produced by the thymus that stimulates the development of T cells, which are important for the immune system. Thymosin was originally identified as a thymic extract that had immune-enhancing properties.

Question 14

How do the parathyroid glands function in opposition to the thyroid glands?

Accepted Answer

The answer of How do the parathyroid glands function in...

Question 15

Prolactin, which is secreted by cells called lactotropes, promotes the development of the mammary glands and the production of milk.

Accepted Answer

This statement is true. Prolactin is a hormone that is secreted by lactotropes in the anterior pituitary gland. Its main function is to promote the development of the mammary glands during pregnancy and the production of milk following childbirth.

Question 16

The two thyroid hormones, thyroxine and triiodothyronine, have complementary effects in which they decrease the rate of cellular metabolism and oxygen consumption in almost every cell in the body.

Accepted Answer

The two thyroid hormones, thyroxine and triiodothyronine, actually increase the rate of cellular metabolism and oxygen consumption in almost every cell in the body.

Question 17

In the pancreas, alpha cells produce the hormone insulin, which lowers blood glucose by increasing the rate of glucose uptake and utilization by most body cells.

Accepted Answer

Alpha cells in the pancreas actually produce glucagon, which raises blood glucose levels by promoting the breakdown of glycogen in the liver and the release of glucose into the bloodstream. Beta cells produce insulin.

Question 18

F cells produce the hormone pancreatic polypeptide (PP), which inhibits gallbladder contractions and regulates the production of some pancreatic enzymes.

Accepted Answer

F cells, located in the pancreas, do produce pancreatic polypeptide (PP), which has been shown to inhibit gallbladder contractions and regulate some pancreatic enzymes.

Question 19

All the cortical cells of the adrenal gland have abundant rough ER for the manufacture of steroids.

Accepted Answer

Steroid hormones are synthesized in the smooth endoplasmic reticulum (smooth ER) and mitochondria, not the rough ER, which is primarily involved in protein synthesis.

Question 20

Chromaffin cells, which are large, rounded cells of the medulla of the adrenal gland, resemble the neurons in sympathetic ganglia and are innervated by preganglionic sympathetic fibers.

Accepted Answer

Chromaffin cells are indeed innervated by preganglionic sympathetic fibers and morphologically resemble neurons in sympathetic ganglia.

Quiz 19: The Endocrine System