Chapter 16 Anatomy

Parathyroid Glands

Primary regulators of blood calcium levels.

Pancreas

Produces hormones that regulate glucose levels in the body.

Thyroid Gland

Produces the body's major metabolic hormones.

Which hormone has only one known effect: to stimulate milk production by the breasts?

prolactin

The hypothalamic-hypophyseal tract ________.

runs through the infundibulum

Virtually all amino acid-based hormones exert their signaling effects through intracellular ________.

second messengers

Antidiuretic hormone (ADH) ________.

secretion is inhibited by alcohol

Adrenocorticotropic hormone (ACTH) ________.

secretion is regulated by a hypothalamic regulatory hormone

What amino acid-based hormone uses the direct gene activation method?

thyroxine

What is the name for the type of hormone, secreted by the pituitary that regulates other endocrine organs?

tropins --Tropins, or tropic hormones, are hormones that regulate the secretory action of other endocrine glands.

n 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 ________.

up-regulation

Dave has discovered a new lipid-soluble hormone. Which of the following is true regarding this hormone?

will be bound to a transport protein in the blood

Which of the following pairs correctly matches the adrenal gland zone, or area, with the class of hormones it produces?

zona glomerulosa: mineralocorticoids

Adrenocorticotropic Hormone

Adrenal cortex

Growth Hormone

Bones and muscles

Where are the hormones oxytocin and antidiuretic hormone (ADH) stored?

C) --The axon terminals of neurons of the hypothalamic-hypophyseal tracts store and secrete ADH and oxytocin in the capillaries of the inferior hypophyseal artery.

Aldosterone is the most potent mineralocorticoid produced by the adrenal glands but the least abundant.

False

All amino acid based hormones are lipid soluble and can cross the plasma membrane.

False

Direct gene activation involves a second-messenger system.

False

Oxytocin and ADH are produced in the posterior pituitary.

False

The endocrine gland that is probably malfunctioning if a person has a high metabolic rate is the parathyroid.

False

The hormone that raises blood sugar levels is insulin.

False

ACTH stimulates the adrenal cortex to release corticosteroid hormones.

True

Both "turn on" factors (hormonal, humoral, and neural stimuli) and "turn off" factors (feedback inhibition and others) may be modulated by the activity of the nervous system.

True

Iodine is an essential element required for the synthesis of thyroxine.

True

LH is also referred to as a gonadotropin.

True

Oxytocin is a strong stimulant of uterine contractions.

True

The adrenal medulla is stimulated to release catecholamines during sympathetic autonomic nervous responses.

True

The beta cells in the pancreatic islets produce insulin.

True

Hypersecretion of what hormone can produce the effects of gigantism in the individual in the center of this image?

Growth Hormone

Which of the following best describes the hypoglycemic effect of insulin?

Insulin allows entry of glucose into most body cells.

Adrenal Medulla

Is part of the sympathetic nervous system.

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

It does not require a second messenger to cause a response.

If a person's parathyroids are responding properly to a drop in blood calcium, which of the following should result?

Less calcium is placed in the urine by the kidneys.

Which of the following triggers the release of glucagon?

a decrease in blood glucose levels

Which of the following is a parathyroid gland mechanism to maintain adequate levels of blood calcium?

activation of osteoclasts increased intestinal absorption of calcium ions increased calcium ion reabsorption by the kidneys

Which of the following hormones is stimulated by stress?

adrenocorticotropic hormone

What hormone is released by the anterior pituitary to target the adrenal cortex when we are under stress?

adrenocorticotropic hormone (ACTH)

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

aldosterone

What is the primary function of hormones?

alter cell activity

What gland secretes growth hormone?

anterior pituitary

Which of the following hormones helps the body avoid dehydration and water overload?

antidiuretic hormone

What hormone released into the blood by the posterior pituitary inhibits or prevents urine formation?

antidiuretic hormone (ADH)

The second-messenger mechanism of hormone action operates by ________.

binding to specific receptors and employing the services of G proteins and cAMP

The major targets of growth hormone are ________.

bones and skeletal muscles

What hormone is released by the cells pictured in letter D?

calcitonin--These humorally-stimulated cells respond to increasing levels of calcium in the blood and secrete calcitonin to counteract it

What is the target organ of thyroid hormones' metabolic effects?

cells of the body

Gluconeogenesis, the formation of glucose from fats and proteins, is due to the action of ________.

cortisol

Mineralocorticoid is to aldosterone as glucocorticoid is to ________.

cortisol

Steroid hormones exert their action by ________.

entering the nucleus of a cell and initiating or altering the expression of a gene

Regulating hormones from the hypothalamus ________.

first enter into the hypophyseal portal system

Aldosterone ________.

functions to increase sodium reabsorption

Thyroid- stimulating Hormone

Thyroid

Which of the following are characteristics of water-soluble hormones?

-act through second messengers -free in plasma -short half-life in blood

Which of the following is a change typically produced by a hormonal stimulus?

-induces secretory activity -activates or deactivates enzymes -alters plasma membrane permeability

Steroid hormones are synthesized from amino acids.

False --Steroid hormones are lipid-based hormones synthesized from cholesterol.

Up-regulation involves the loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.

False--Down-regulation involves the loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.

The benefit of using a second messenger signaling system is rapid speed of communication.

False--The benefit of second messenger signaling is the amplification that occurs inside of the cells; small amounts of signal create a large response.

The hypothalamus is known to control the activity of the thyroid, which has traditionally been called the master endocrine gland.

False--The hypothalamus is known to control the activity of the pituitary gland, which has traditionally been called the master endocrine gland.

Water-soluble hormones are metabolized quickly by the liver.

False--Water-soluble hormones are removed from the blood quickly because they are filtered and removed by the kidneys.

Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________.

G protein acts as the link between first and second messengers

Prolactin

Mammary glands

Which of the following is a hormone produced by the posterior pituitary? prolactin ADH oxytocin None of the listed responses is correct.

None of the listed responses is correct.

__________ is the situation when one hormone exaggerates the effects of another hormone at the target cell?

Synergism

At which point has the hormone bound to its intracellular receptor but not yet entered the nucleus?

The receptor-hormone complex has formed and is about to enter the nucleus

Pituitary Gland

The size and shape of a pea; produces hormones that stimulate other endocrine glands.

Which of the following is NOT representative of endocrine glands?

They have ducts.

What is required for the production of anterior pituitary gland hormones?

hormonal stimuli

Chemical substances secreted by cells into the extracellular fluids that travel through the blood and regulate the metabolic function of other cells in the body are called ________.

hormones

The parathyroid glands respond to which type of stimulus?

humoral

What type of stimulation controls parathyroid release?

humoral

Which of the following is a major type of stimulus that triggers endocrine glands to manufacture and release hormones?

humoral neural hormonal

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?

humoral stimulation

Several hormones are synthesized in the hypothalamus and transported to the anterior pituitary gland. The mechanism of transportation from hypothalamus to anterior pituitary gland is through the ________.

hypophyseal portal system

Where is thyrotropin-releasing hormone (TRH) made?

hypothalamus

Variance in which of the following hormones is responsible for diabetes mellitus (DM)?

insulin

What material is stored in the thyroid follicles?

iodinated thyroglobulin, from which thyroid hormone can be released --Follicular cells prepare thyroglobulin, which is released and bound with iodine in the follicle. This material is stored in the follicle until thyroid hormone is needed by the body.

The posterior lobe of the pituitary gland is true endocrine gland because ________.

it is strictly a part of the neural system and has little or nothing to do with hormonal release it is unable to function as an endocrine tissue because it is actually part of the neural system due to its location embryonically it was an endocrine tissue, but in the adult human it is no longer functional

What property of a hormone would allow it to pass unassisted through a plasma membrane?

lipid-soluble

Which anterior pituitary hormone targets another endocrine gland?

luteinizing hormone follicle-stimulating hormone adrenocorticotropic hormone (ACTH)

Upon landing at the airport in Lagos, Nigeria, Eric feels wide awake even though the local time is 11pm. Which synthetic hormone supplement could he administer to help adjust to the new time zone?

melatonin

Which of the following glands increases blood calcium levels?

parathyroid

Which of the following is a type of hormone interaction?

permissiveness synergism antagonism

Which of the following occurs in situations where more than one hormone produces the same effects at the target cell and their combined effects are amplified?

synergism

Which of the following best describes gluconeogenesis?

synthesis of glucose from noncarbohydrate sources

Follicle- stimulating Hormone

testes and ovaries

John tells you that cholesterol is bad and should be eliminated from the diet. You explain to him that cholesterol is important. Which of the following hormones are synthesized from cholesterol?

testosterone

What allows a cell to respond to a hormone?

the presence of a specific hormone receptor

The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on ________.

the presence of the appropriate receptors on the cells of the target tissue or organ

Which of the following is an endocrine gland?

thyroid, pituitary, adrenal