Question 1

Regulating hormones from the hypothalamus ________.
A) enter the hepatic portal system, which feeds the pituitary
B) first enter into the hypophyseal portal system
C) enter venous circulation and travel to the heart, which pumps the hormone-containing blood to the pituitary
D) travel by arteries to the pituitary

Accepted Answer

Hormones from the hypothalamus first enter into the hypophyseal portal system, which is a specialized capillary bed that connects the hypothalamus to the anterior pituitary gland. This allows for direct and efficient communication between the hypothalamus and pituitary gland.

Question 2

In circumstances where the body requires prolonged or increased levels of a hormone,the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ.This is known as ________.
A) a stressor reaction
B) sensitivity increase
C) up-regulation
D) cellular affinity

Accepted Answer

Up-regulation is the process where the DNA of the target cells specify the synthesis of more receptors on the surface of the cells of the target organ in response to prolonged or increased levels of a hormone. This makes the target cells more sensitive to the hormone, allowing for better regulation of bodily processes.

Question 3

The single most important regulator of calcium levels in the blood is ________.
A) thyroid hormone
B) gonadotropic hormones
C) calcitonin
D) parathyroid hormone

Accepted Answer

The parathyroid hormone is the single most important regulator of calcium levels in the blood. It increases blood calcium levels by stimulating the break down of bone and increasing the reabsorption of calcium by the kidneys.

Question 4

Which anterior pituitary hormone does NOT target another endocrine gland?
A) adrenocorticotropic hormone (ACTH)
B) growth hormone
C) luteinizing hormone
D) follicle-stimulating hormone

Accepted Answer

Growth hormone does not target another endocrine gland. Instead, it acts directly on tissues throughout the body to promote growth and repair.

Question 5

Adrenocorticotropic hormone (ACTH)________.
A) causes the release of hormones from the adrenal medulla
B) is secreted by the posterior pituitary
C) is not a tropic hormone
D) secretion is regulated by a hypothalamic regulatory hormone

Accepted Answer

ACTH is a tropic hormone secreted by the anterior pituitary and its secretion is regulated by a hypothalamic releasing hormone called corticotropin-releasing hormone (CRH). Its primary function is to stimulate the release of glucocorticoid hormones from the adrenal cortex in response to stress.

Question 6

Which organ does NOT produce hormones?
A) heart
B) spleen
C) kidney
D) skin

Accepted Answer

The heart, kidney, and skin all produce hormones, but the spleen does not have a major endocrine function.

Question 7

Which of the following is NOT a steroid-based hormone?
A) estrogen
B) cortisol
C) epinephrine
D) aldosterone

Accepted Answer

Epinephrine is not a steroid-based hormone. Estrogen, cortisol, and aldosterone are all steroid-based hormones.

Question 8

Eicosanoids do NOT include ________.
A) leukotrienes
B) prostaglandins
C) hydrocortisones
D) paracrines

Accepted Answer

Hydrocortisones are not classified as eicosanoids, as they are a type of steroid hormone produced by the adrenal cortex. Eicosanoids are local signaling molecules that include leukotrienes, prostaglandins, and thromboxanes, but not hydrocortisones. Paracrines, on the other hand, are a general term for signaling molecules that act locally within a tissue and can include eicosanoids.

Question 9

Mineralocorticoid is to aldosterone as glucocorticoid is to ________.
A) testosterone
B) estrogen
C) epinephrine
D) cortisol

Accepted Answer

Mineralocorticoids, such as aldosterone, are hormones that regulate electrolyte balance and blood pressure. Glucocorticoids, such as cortisol, have a wider range of functions including regulating glucose metabolism and immune responses. Therefore, the counterpart to mineralocorticoid is glucocorticoid.

Question 10

Thyroid hormone (a small iodinated amine)enters target cells in a manner similar to ________.
A) steroid hormones, because both diffuse easily into target cells
B) glucagon, because the structure of glucagon is similar to that of thyroid hormone
C) insulin, because insulin is a small peptide
D) growth hormone, because the thyroid works synergistically with thyroid hormone

Accepted Answer

Thyroid hormone is a small molecule, similar to steroid hormones, and can easily diffuse across the plasma membrane to enter target cells. It does not require a receptor to bind to in order to enter the cell like insulin or glucagon.

Question 11

The most important mineralocorticoid regulator of electrolyte concentrations in extracellular fluids is ________.
A) cortisol
B) insulin
C) glucagon
D) aldosterone

Accepted Answer

Mineralocorticoids are a class of steroid hormones that regulate electrolyte and fluid balance in the body, particularly by promoting the reabsorption of sodium ions and the excretion of potassium ions by the kidneys. Of the mineralocorticoids, aldosterone is the most important regulator of electrolyte concentrations in extracellular fluids. It acts primarily on the distal tubules and collecting ducts of the kidneys to increase sodium and water reabsorption and potassium excretion. Cortisol is a glucocorticoid that also has mineralocorticoid activity but is less potent than aldosterone in regulating electrolytes. Insulin and glucagon are hormones that regulate glucose metabolism and do not have a direct role in electrolyte balance.

Question 12

The major targets of growth hormone are ________.
A) bones and skeletal muscles
B) the liver and gall bladder
C) the adrenal glands
D) the blood vessels

Accepted Answer

Growth hormone primarily targets bone and skeletal muscle cells, promoting cell growth and division in these tissues.

Question 13

Thyroxine is a peptide hormone,but its mechanism is different from other peptide hormones.Which of the following statements is true concerning this difference?
A) It is very specific in the cell type it targets.
B) It is a stimulant of cellular metabolism and targets all cells.
C) It causes positive feedback.
D) It does not require a second messenger to cause a response.

Accepted Answer

Thyroxine, unlike most peptide hormones which act through second messengers, directly enters the cell and acts on the nucleus to change gene expression, thus not requiring a second messenger system.

Question 14

Cellular responses to hormones that initiate second-messenger systems include ________.
A) possible activation of several different second-messenger systems
B) hormone binding to intracellular receptors
C) cyclic AMP phosphodiesterase formation of an active second messenger
D) formation of a specific protein kinase that acts on a series of extracellular intermediates

Accepted Answer

Cellular responses to hormones that initiate second-messenger systems can result in the activation of several different second-messenger systems, such as cyclic AMP, inositol triphosphate (IP3), and diacylglycerol (DAG). Different types of cells and different hormones can activate different second-messenger systems, leading to diverse physiological responses. The other answer choices are not accurate descriptions of second-messenger systems.

Question 15

A man has been told that he is NOT synthesizing enough follicle-stimulating hormone (FSH),and for this reason he may be unable to father a child.Choose the correct statement to explain this problem.
A) A hormone made in the anterior pituitary cannot influence fertility.
B) The man must be producing progesterone, which inhibits the synthesis of FSH.
C) FSH stimulates sperm production in the testes.
D) FSH stimulates estrogen secretion by ovarian cells; therefore it is not synthesized by males.

Accepted Answer

FSH stimulates sperm production in the testes, so a deficiency in FSH production could lead to infertility in males.

Question 16

One of the least complicated of the endocrine control systems directly responds to changing blood levels of ions and nutrients.Which of the following describes this mechanism?
A) carbohydrate oxidation
B) protein synthesis
C) catabolic inhibition
D) humoral stimulation

Accepted Answer

This mechanism is called humoral stimulation, where the endocrine system responds to changing levels of ions and nutrients in the blood. Hormones are released in response to the changes, which can affect the target cells/organs and help maintain homeostasis. Choice A (carbohydrate oxidation) and Choice B (protein synthesis) are not directly related to this mechanism, and Choice C (catabolic inhibition) is not a commonly used term in endocrine control systems.

Question 17

Leptin is secreted by ________.
A) adipose cells
B) fibroblasts
C) goblet cells
D) lymphocytes

Accepted Answer

Leptin is a hormone primarily secreted by adipose cells (fat cells).

Question 18

Aldosterone ________.
A) is secreted by the posterior pituitary
B) presence increases potassium concentration in the blood
C) production is greatly influenced by ACTH
D) functions to increase sodium reabsorption

Accepted Answer

Aldosterone functions to increase sodium reabsorption, which helps to maintain electrolyte balance and blood pressure. It is secreted by the adrenal cortex, not the posterior pituitary. Its production is primarily regulated by the renin-angiotensin system, not ACTH. Its presence does not increase potassium concentration in the blood, but rather promotes its excretion.

Question 19

Which of the following is NOT a parathyroid gland mechanism to maintain adequate levels of blood calcium?
A) inhibition of calcitonin synthesis
B) increased intestinal absorption of calcium ions
C) increased calcium ion reabsorption by the kidneys
D) activation of osteoclasts

Accepted Answer

The parathyroid gland does not inhibit calcitonin synthesis. Calcitonin is produced by the thyroid gland and opposes the actions of parathyroid hormone to decrease blood calcium levels by inhibiting osteoclasts and increasing calcium deposition in bones. The other choices are mechanisms used by the parathyroid gland to maintain adequate levels of blood calcium: increased intestinal absorption of calcium ions, increased calcium ion reabsorption by the kidneys, and activation of osteoclasts to release calcium from bones.

Question 20

How do glucocorticoids enable the body to deal appropriately with stress?
A) by increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure
B) by stimulating the pancreas to release insulin
C) by releasing the neurotransmitters that prepare the body for the stress response
D) by decreasing the heart rate, thus decreasing blood pressure

Accepted Answer

Glucocorticoids such as cortisol increase blood glucose, fatty acid, and amino acid levels to provide energy for the body to deal with stress. They also enhance blood pressure to ensure adequate blood flow to the brain and other organs during stressful situations.

Quiz 16: The Endocrine System

Regulating hormones from the hypothalamus ________.

In circumstances where the body requires prolonged or increased levels of a hormone,the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ.This is known as ________.

The single most important regulator of calcium levels in the blood is ________.

Which anterior pituitary hormone does NOT target another endocrine gland?

Adrenocorticotropic hormone (ACTH) ________.

Which organ does NOT produce hormones?

Which of the following is NOT a steroid-based hormone?

Eicosanoids do NOT include ________.

Mineralocorticoid is to aldosterone as glucocorticoid is to ________.

Thyroid hormone (a small iodinated amine) enters target cells in a manner similar to ________.

The most important mineralocorticoid regulator of electrolyte concentrations in extracellular fluids is ________.

The major targets of growth hormone are ________.

Thyroxine is a peptide hormone,but its mechanism is different from other peptide hormones.Which of the following statements is true concerning this difference?

Cellular responses to hormones that initiate second-messenger systems include ________.

A man has been told that he is NOT synthesizing enough follicle-stimulating hormone (FSH) ,and for this reason he may be unable to father a child.Choose the correct statement to explain this problem.

One of the least complicated of the endocrine control systems directly responds to changing blood levels of ions and nutrients.Which of the following describes this mechanism?

Leptin is secreted by ________.

Aldosterone ________.

Which of the following is NOT a parathyroid gland mechanism to maintain adequate levels of blood calcium?

How do glucocorticoids enable the body to deal appropriately with stress?