Chapter 16: Endocrine System

How do protein kinases affect enzymes

They add a phosphate group (phosphorylation) to the enzyme

What gland would produce the hormone needed to restore homeostasis when you have loss of Na+ from profuse sweating?

adrenal cortex

Cortisol belongs to which category of hormones?

glucocorticoids

Your patient has been diagnosed with Type I diabetes mellitus, and you are explaining how to administer insulin. Your patient states, "I don't want to do this. My brother-in-law has diabetes, and he just takes a pill and watches what he eats." What is your best response?

"Your relative may have Type II diabetes. People with that condition can make insulin, but their cells don't respond to it properly. Your pancreas doesn't manufacture insulin." (A simple explanation of the differences between Type I and Type II diabetes may help your patient to understand the importance of the prescribed insulin regimen)

Which of the following homeostatic imbalances usually results from deficits in both glucocorticoids and mineralocorticoids?

Addison's disease

Which hormone is secreted by the adrenal cortex?

Aldosterone

select the incorrect statement regarding a negative feedback mechanism - This mechanism maintains many hormones within a narrow range. -As hormone levels decrease, feedback promotes more hormone release. -As hormone levels decrease, feedback inhibits further hormone release. -As hormone levels increase, feedback inhibits hormone release.

As hormone levels decrease, feedback inhibits further hormone release. Explanation: response is opposite than stimulus to maintain balance.

describe a major difference between hormonal and neural controls of body functioning

Hormonal responses last longer than responses to nervous impulses.

Identify the correct statement regarding water-soluble hormones. - Water-soluble hormones have shorter half-lives than lipid soluble hormones. -Water-soluble hormones must be bound to plasma proteins in order to be transported in blood. -Water-soluble hormones usually have receptors inside a cell. -Water-soluble hormones cannot be stored in secretory vesicles.

Water-soluble hormones have shorter half-lives than lipid soluble hormones (water soluble hormones are rapidly removed from the blood by the kidneys, which gives them a very short half-life)

glucocorticoids are produced by the

adrenal cortex Explanation: the adrenal cortex synthesizes corticosteroids. the cells of the middle layer, the zona fasciulata, mainly produce the metabolic hormones called glucocorticoids.

What tropic hormone stimulates cortisol from the adrenal gland?

adrenocorticotropic hormone (ACTH) (it stimulates the adrenal cortex to produce cortisol; another main stimuli for cortisol is stress)

if you have a homeostatic imbalance of excessive loss of Na+ in extracellular fluids, what hormone will help keep that balance?

aldosterone

the word root ______ means blood or lymph vessels

angio

upon the release of renin, ______ is produced ad stimulates vasoconstriction and the release of aldosterone

angiotensin II

When one hormone opposes the action of another hormone, the interaction is called

antagonism

Which hormone aids in water resorption?

antidiurectic hormone (ADH) (stimulates kidney tubules to reabsorb water)

What is the function of melatonin?

associated with drowsiness at night

which hormone would be released in response to a rise in blood pressure?

atrial natriuretic peptide Explanation: secreted by the heart when BP rises. fine-tunes BP and sodium-water balance of the body. one major effect is to inhibit renin-angitotensin-aldosterone mechanism. overall, decreases BP by allowing NA + and water to flow out of body in urine.

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

axon terminals of neurons of the hypothalamic-hypophyseal tracts

Steroid hormones influence cellular activities by __________

binding to DNA and directly activating genes

Lipid-soluble hormones communicate with a target cell by______.

binding to receptors inside the cell

What is the function of the ventral hypothalamic neurons?

control secretion of thyroid stimulating hormone (TSH) Explanation: neurohormones from ventral hypothalamic neurons are known as releasing and inhibiting hormones, RH and IH. they control the release of pituitary hormones such as adrenocorticotropic hormone and TSH

which of the following hormones is secreted by the adrenal gland?

cortisol

sympathetic nerve stimuli are responsible for the release of

epinephrine

the adrenal medulla produces which hormone?

epinephrine

One of the short-term stress responses is

epinephrine release from the adrenal medulla Explanation: short-term stressors can activate fight or flight; another name for epinephrine is adrenaline

the cell clusters in the zona fasciculata produce

glucocorticoids (the cell clusters of the zona fasciulata mainly produce metabolic hormones called glucocorticoids, such as cortisol)

Select the chemical classification description that does not apply to hormones. amino acid based synthesized from cholesterol steroid glucose based

glucose based

Androgens secreted by the adrenal cortex belong to which category of hormones

gonadocorticoids

FSH and LSH are exxamples of _______ hormones which target the ovaries or testes

gonadotropic

Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones?

growth hormone (GH) Explanation: GH stimulates IGFs from the liver. these IGFs are needed for GH to cause growth in bones and skin.

Select the statement that best illustrates hormonal stimuli of an endocrine gland. - Hormone release in response to changing blood levels of ions. - Hormone release dependent upon other hormone levels. - Hormone release dependent upon signals from the thalamus. - Hormone release caused by preganglionic sympathetic fibers.

hormone release dependent upon other hormone levels

Endocrinology involves the study of the endocrine organs and __________.

hormones

What is known as a neuroendocrine organ?

hypothalamus

Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized?

hypothalamus Explanation: ADH is mainly synthesized in the supraoptic nucleus of the hypothalamus and it is stored in axon terminals in the posterior pituitary.

what is the function of aldosterone?

increases Na + reabsorption in the kidneys

the function of epinephrine is that it

increases heart and metabolic rate

which of the following is not a major endocrine gland? Kidney Pituitary Thyroid Adrenal

kidney

the pineal gland secretes which hormone?

melatonin

the cell clusters in the zona glomerulosa produce

mineralocorticoids

What is the most important regulatory factor controlling the circulating levels of thyroid hormone?

negative feedback Explanation: if thyroid levels high, neg. feedback decreases TSH and TRH which in turn decreases thyroid hormones.

Which hormone is regulated by a neuroendocrine ("letdown") reflex?

oxytocin Explanation: sucking of infant or stretching of uterus releases oxytocin which causes milk let-down effect or increased uterine contractions

These chemical signals act locally but affect cell types other than the releasing cells.

paracrines

Which gland secretes the most important hormone controlling calcium balance in the blood?

parathyroid Explanation: PTH is the most important hormone to control calcium balance in blood.

A patient is being treated by her urologist for a fourth episode of kidney stones. Analysis of the stones shows that they are composed of calcium oxalate. The urologist orders an assay of which hormone?

parathyroid hormone (PTH) Explanation: Inappropriately high levels of PTH may result in excess calcium in the blood, which might precipitate in the urine. The result is renal lithiasis, or kidney stones.

__________________ is a property in which a hormone cannot exhibit its full effect without another hormone being present.

permissiveness

the word root_____ means feeding or eating

phag

The word root _______ means phosphate or phosphorous

phospho-

an enzyme that degrades second messengers like cAMP or cGMP is ___________

phosphodiesterase

overeating, or _____ is a sign associated with diabetes mellitus

polyphagia

overproduction of urine, or ______ is a sign of diabetes mellitus

polyuria

identify a function of gonadocorticoids

produce masculinizing effects when produced in large quantities

Which hormone stimulates mammary glands to produce milk in nursing mothers?

prolactin (after birth, sucking stimulates release of prolactin-releasing factors for continued milk production)

In a mechanism designed to increase blood volume/blood pressure, place the following substances in the correct sequence that would result in increased absorption of Na+ (and water).

renin- angiotensin II- aldosterone Explanation: this mechanism influences blood volume and pressure by regulating release of aldosterone and Na + and water reabsorption by the kidneys. 1. when blood pressure falls, special cells of juxtaglomerular complex of kidneys excited 2. cells release renin into blood 3. renin splits off part of plasma protein angiotensinogen which triggers enzymatic cascade that creates angiotensinogen II which stimulates glomerulosa cells to release aldosterone

The transcription of new messenger RNA is a function of __________

steroid hormones

Your patient has been admitted to the intensive care unit with a severe head injury. As you monitor his urine output, you find that it has fallen sharply. Lab tests indicate that his serum osmolality is lower than normal (i.e., his plasma is too dilute). What should you suspect?

syndrome of inappropriate antidiuretic hormone (SIADH) Explanation: Antidiuretic hormone (ADH) is released from the posterior pituitary in response to rising serum osmolality. This causes the kidneys to preserve water, helping to restore normal solute/water balance. Your patient is retaining water despite a dilute plasma, suggesting that he is making "inappropriate" ADH. This problem may occur after head trauma or in some cancers.

Eicosanoids are not considered true hormones because __________

their effects are usually highly localized

Which hormone stimulates an increase in basal metabolic rate as a tropic hormone?

thyroid-stimulating hormone (TSH) Explanation: TSH stimulates thyroid to release thyroxin which increases metabolism in body

the word root _____ means attracted specifically to the specified organ or tissue

tropic

The various hormones secreted by the anterior pituitary that regulate the secretion of hormones from other endocrine organs are called __________

tropins Four of the six anterior pituitary hormones—thyroid-stimulating hormone (thyrotropin), adrenocorticotropic hormone (corticotropin), follicle-stimulating hormone and luteinizing hormone (gonadotropins)—are tropins (tropic hormones) that regulate the secretory action of other endocrine glands.

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

tropins/ tropic hormones

the word root ______ means urine

uria

Which mechanism of hormone action utilizes intracellular calcium ions as a second messenger?

PIP2-calcium

What is the function of the glucocorticoids?

Increase blood levels of glucose, fatty acids, and amino acids during stress