Endocrine System Flashcards by Rachel Kozlow

The structure that controls hormone release by both the anterior pituitary and the posterior pituitary is the ________.

hypothalamus

The hypothalamus secretes releasing hormones to the anterior pituitary and produces the hormones released by the posterior pituitary.

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From which part of the pituitary are the hypothalamic hormones (antidiuretic hormone and oxytocin) released?

posterior pituitary

These hormones are produced in the hypothalamus, but they are released from the posterior pituitary, which does not produce its own hormones.

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The releasing hormones from the hypothalamus travel through the ___________ and _________ out to the anterior pituitary.

blood vessels (capillaries)…diffuse

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FSH is produced in the ___________ and stimulates both _____ production and ____ development.

anterior pituitary…sperm..,egg

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LH is produced in the __________ and stimulates both __________ production and ______

anterior pituitary…testosterone…ovulation

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In response to the rise in glucose levels in the bloodstream following a meal, the __________ of the pancreas release insulin.

beta cells

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Which of the following statements is CORRECT in regard to the role of insulin in blood glucose regulation?

a. Glucose requires insulin to cross cell membranes.
b. Insulin is released when blood glucose levels rise.
c. Insulin stimulates the storage of glucose as glycogen in the liver and muscles.
d. All of these statements are correct.

d. All of these statements are correct.

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Glucagon stimulates __________ , the breakdown of glycogen, to increase blood glucose concentrations.

glycogenolysis

Blood glucose levels drop several hours after eating. The decrease in blood glucose stimulates the alpha cells of the pancreas to release the hormone glucagon. Glucagon stimulates glycogenolysis and gluconeogenesis. Glycogenolysis is the breakdown of glycogen to yield glucose. Gluconeogenesis is the process of making glucose out of amino acids and other compounds. Glucose released into the bloodstream from glycogenolysis or gluconeogenesis helps to increase the concentration of glucose in the blood back to normal.

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Which of these glands secretes releasing hormones?

a. hypothalamus
b. adrenal cortex
c. thymus
d. ovaries
e. testes

a. hypothalamus

The hypothalamus secretes both releasing and inhibiting hormones.

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Which of these hormones are responsible for the “fight or flight” response to danger?

a. insulin and glucagon
b. thyroxine and calcitonin
c. androgens and estrogens
d. antidiuretic hormone (ADH) and oxytocin
d. epinephrine and norepinephrin

d. epinephrine and norepinephrin

These hormones, secreted by the adrenal medulla, are responsible for the “fight or flight” response.

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Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.

glucocorticoids

In response to stress, ACTH stimulates the adrenal cortex to secrete glucocorticoids.

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_____ are the main male hormones.

Androgens

Androgens, such as testosterone, are the main male hormones

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What hormone promotes water retention by the kidneys?

antidiuretic hormone (ADH)

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Which hormone opposes the action of parathyroid hormone?

calcitonin

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Which hormone stimulates hormone production by the ovaries and testes?

luteinizing hormone (LH)

LH stimulates hormone production by both the ovaries and testes.

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Which hormone stimulates milk production?

prolactin

Prolactin, secreted by the anterior pituitary, stimulates milk production by the mammary glands.

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In ___________ , target cells do not respond normally to insulin.

type 2 diabetes

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In ___________ , no insulin is produced.

type 1 diabetes

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In ____________ , glucose levels remain higher than normal.

both type 1 and type 2 diabetes

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Which of the following statements about the functions of hormones is MOST correct?

a. Hormones affect energy utilization.
b. Hormones can affect the activities of the plasma membrane.
c. Hormones may be involved in secretory activity.
d. Hormones influence protein synthesis.
e. All of the listed responses are correct.

e. All of the listed responses are correct.

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____________ is secreted in response to low levels of blood calcium.

Parathormone

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True or false. The adrenal gland secretes hormones that slow down the heart rate and lower blood glucose levels.

False.

The adrenal gland secretes epinephrine and norepinephrine in response to stress; they speed up the heart and increase blood glucose levels.

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You just ate about half your birthday cake. Which of the following is happening in your body?
Glucose ______, insulin ________, glucagon _________.

increases….increases…decreases

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How are hormones related to the interaction of the nervous system and muscular system?
The nervous system can control muscle movement by controlling the release of ________.

hormones

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When considering receptors for hormone molecules, we can say that, in general, receptors for lipid-soluble hormones are ________, whereas receptors for lipid-insoluble hormones are ___________.

inside the cell... on or in the cell membrane Lipid-soluble hormones can pass through the phospholipids of the cell membrane. But nonlipid hormones are insoluble in the membrane and must bind to a receptor that is on the outside of the cell membrane.

When a hormone binds to a receptor, the resulting molecule is called a(n) ________.

hormone-receptor complex

Which type of hormone is most likely to react with and activate a portion of a DNA molecule?

steroid Steroids are lipids and thus can cross the membranes to enter the cell.

If a gene is activated by a hormone, what is the most likely chain of events? A strand of _____ is transcribed in the nucleus. It leaves the nucleus for the _________. The message is translated into a new ________.

mRNA...cytoplasm...protein | Hormone-activated protein synthesis is the same as any protein synthesis.

Which of the following statements would be the best way to describe or define the concept of the second messenger? a. Second messenger is another term for the amino acid and protein hormones. b. Second messenger is another name for cyclic AMP. c. A second messenger is a hormone-like substance that takes over and does the work of a hormone. d. Second messenger is another name for the steroid hormones. e. When the binding of the hormone to a membrane receptor (the "first messenger") activates another molecule within the cell (often cyclic AMP), that activated molecule is the second messenger.

e. When the binding of the hormone to a membrane receptor (the "first messenger") activates another molecule within the cell (often cyclic AMP), that activated molecule is the second messenger. The hormone responsible for this action is often a protein or an amino acid hormone. This hormone (the "first messenger") activates a molecule within the cell, known as a "second messenger."

Which of the following hormones has intracellular receptors?

cortisol Cortisol is one of the lipid-soluble steroid hormones. Thyroid hormones are also lipid soluble.

What is the mechanism of action of lipid-soluble hormones?

activation of genes, which increases protein synthesis in the cell. lipid-soluble hormones diffuse into the nucleus or they diffuse into the cytoplasm and then move into the nucleus, where they affect transcription and translation.

After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do?

acts as a transcription factor and binds to DNA, activating a gene

Which hormone’s receptor is always bound to DNA, even when the receptor is empty?

thyroid hormone Thyroid hormones are lipid soluble and their receptors are bound to the response elements of the DNA

What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor?

chaperone proteins (chaperonins) Yes, each receptor has two binding sites. The chaperone protein blocks the DNA binding site until a hormone binds at the hormone binding site.

What type of hormones bind to receptors located on the cell membrane?

water-soluble hormones, such as insulin and epinephrine Yes, peptides and catecholamines are water-soluble hormones that cannot diffuse through the plasma membrane.

Which intracellular substance degrades cAMP, thus inactivating the response to a hormone?

phosphodiesterase

Growth factor hormones, such as insulin, bind to which type of receptor?

tyrosine kinase receptors

Which is the correct order of events for hormones activating Gs proteins?

activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP

Which second messenger causes the release of calcium from the endoplasmic reticulum?

IP3 Yes, inositol trisphosphate releases calcium from intracellular storage sites.

Which of the following adrenergic receptors increase cAMP levels?

β receptors Yes, these receptors are coupled to adenylate cyclase by Gs receptors that increase cAMP.

Receptors for nonsteroid hormones are located in association with a cell's _______ _____.

plasma membrane

epinephrine and oxytocin are ___________ hormones.

nonsteroid

Steroid vs nonsteroid _________ hormones act via signal transduction pathways; _________ hormones do not act via signal transduction pathways

nonsteroid... steroid

Steroid hormones such as _________ can diffuse through the plasma membrane and bind to intracellular receptors.

estrogen

The primary reason steroid hormones usually act slowly is that _____.

they turn genes on or off and it takes time for gene products to build up or become depleted

Steroid hormone-receptor complexes act in _____.

the nucleus Steroid hormone-receptor complexes bind to DNA, where they affect transcription.

Events in your body that occur after eating a sugary snack. (5)

1. Blood glucose becomes high. 2. Pancreas releases insulin 3. Insulin binds to receptors on target cells. 4. Cells take in glucose 5. Blood glucose returns to normal

Which of the following hormones is a part of the rapid response (rather than the prolonged response) to stress? a. epinephrine d. ADH (vasopressin) c. aldosterone d. cortisol

a. epinephrine Yes, epinephrine is part of the immediate or rapid response to stress. Epinephrine is released from the adrenal medulla as a result of the increase in the sympathetic nervous system. In fact, the chromaffin cells in the adrenal medulla act like modified postganglionic neurons.

In response to stress, which of the following changes would happen? a. decreased insulin secretion b. decreased cardiac output c. decreased sweating d. decreased or difficulty breathing

a. decreased insulin secretion

Which of the following are symptom(s) of pheochromocytoma? a. heart palpitations b. cool, dry skin c. low blood glucose d. slow heart rate

a. heart palpitations Yes, due to the increase in epinephrine, heart rate would be increased and you would feel like your heart was pounding or racing.

# Choose which condition has all of the following symptoms: hypertension, hyperglycemia, and a “moon face.” a. Addison’s disease b. pheochromocytoma c. Cushing’s disease

c. Cushing’s disease Yes, a patient with Cushing’s would have hypertension, increased blood glucose, and an unusual fat distribution on the face, known as a “moon face.” These symptoms are due to increased levels of cortisol and can also be seen in patients after long periods of steroid treatment.

What hormone also aids the stress response by promoting water retention and acting as a vasoconstrictor?

ADH (vasopressin) ADH increases water reabsorption in the distal tubule and collecting duct of the nephron and its secondary function is to act as a vasoconstrictor.

What tropic hormone stimulates cortisol from the adrenal gland?

adrenocorticotropic hormone (ACTH) ACTH stimulates the adrenal cortex to produce cortisol. Stress and ACTH are the main stimuli for cortisol.

What is the function of the ventral hypothalamic neurons?

control secretion of thyroid stimulating hormone (TSH) Neurohormones from the ventral hypothalamic neurons, known as releasing (RH) and inhibiting (IH) hormones, control the release of anterior pituitary hormones such as adrenocorticotropic hormone (ACTH) and TSH.

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

GH (growth hormone) GH stimulates IGFs from the liver. IGFs are required for the growth effect of GH on bone and skin.

Which of the following hormones is regulated by a neuroendocrine (“letdown”) reflex?

oxytocin

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

hypothalamus ADH is synthesized mainly in the supraoptic nucleus of the hypothalamus. It is stored in the posterior pituitary in axon terminals.

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

negative feedback Negative feedback controls the levels of circulating thyroid hormone. If levels are high, negative feedback will decrease thyroid-stimulating hormone (TSH) (and thyrotropin-releasing hormone (TRH) to some degree), thus decreasing the thyroid hormones.

Which statement regarding calcium is FALSE? a. Calcium makes up approximately 2 percent of body weight. b. Most of the calcium in our bodies, 99 percent, is found in bones and teeth. c. Approximately 50 percent of calcium is found in the blood. d. When dietary calcium is low, calcium is removed from the bone to maintain blood calcium levels.

c. Approximately 50 percent of calcium is found in the blood. This is the false statement. Calcium makes up approximately 2 percent of our body weight. Of that, 99 percent is found in the bones and teeth as part of the hydroxyapatite crystal. The remaining 1 percent is found in the blood and soft tissues. When too little calcium comes from food, our bodies reabsorb it from our bones. If this situation is prolonged, bone density will decrease.

True or False. Calcium is actively absorbed in the upper small intestine with the aid of 1, 25 dihydroxyvitamin D.

True. The active absorption of calcium occurs across the cell membranes of the upper small intestine, where the environment is more acidic. This requires active vitamin D, also known as 1, 25 dihydroxyvitamin D.

Which statement(s) correctly describe(s) the role of hormones in calcium metabolism? Be aware that all statements may be correct. a. Parathyroid hormone and calcitonin stimulate calcium reabsorption by the kidneys. b. Parathyroid hormone is released when dietary calcium levels are low. c. Calcitonin is released when blood calcium levels are high and increases the activity of osteoclast cells in bone, releasing calcium from bone into the blood. d. Intestinal absorption of calcium depends on the level of active vitamin A that we have in our body.

b. Parathyroid hormone is released when dietary calcium levels are low. When a diet is low in calcium, blood calcium levels fall, signalling the parathyroid gland to release another hormone known as parathyroid hormone, or PTH. This hormone stimulates the activation of vitamin D in the kidneys. The activation of vitamin D promotes reabsorption of calcium by the kidney, increases calcium absorption in the intestine, and stimulates osteoclasts to resorb calcium from bone.

True or False. The thyroid hormone calcitonin inhibits the effects of vitamin D on calcium metabolism and works to lower calcium levels in the blood.

True. Thyroid hormone inhibits the effects of vitamin D, resulting in decreased reabsorption of calcium by the kidney, limited calcium absorption in the intestines, and inhibition of osteoclast cells in the bone. All of these effects work to lower calcium levels in the blood.

___________ hormones enters the target cells, activates genes, and brings about the synthesis of new proteins?

steroid hormones

A deficiency of which hormone secreted by the kidneys would result in anemia?

erythropoietin

All steroid hormones are synthesized from ________.

cholesterol

Blood calcium levels will increase under the influence of ________, and decrease under the influence of ________.

PTH; calcitonin

Which glucocorticoid hormone produced by the adrenal glands has anti-inflammatory effects?

cortisol

All of the following hormones are secreted by organs of the digestive system and directly regulate digestive processes EXCEPT ________.

glucagon

Neuroendocrine cells of the hypothalamus function as both ________ and ___________.

both nerve cells and endocrine cells

Endocrine products are a class of molecules called ________.

hormones

The endocrine system and the nervous system can coordinate their activity through the pituitary gland and the ________.

hypothalamus

Which disorder results from the excessive secretion of growth hormone in a child?

gigantism

Which hormone can bring about a "fight-or-flight" response similar to that of the sympathetic nervous system?

epinephrine

Which hormone stimulates the maturation of eggs and the production of estrogen in women, and stimulates the production of sperm in men?

FSH

What determines whether a cell will respond to a specific hormone?

A cell must possess specific receptors for the hormone.

The incidence of which of the following endocrine disorders is increasing most rapidly?

Type 2 diabetes

True or False. An increase in thyroxine secretion increases the basal metabolic rate (BMR).

True.

True or False. Atrial natriuretic hormone is secreted by the heart and helps to regulate blood pressure.

True.

True or False. The secretion of melatonin by the pineal gland is much greater during the day than during the night.

False.

True or False. Medically, cortisol may be administered to help relieve inflammation.

True.

True or False. Epinephrine can function as both a neurotransmitter and a hormone.

True.

True or False. Both effective as communication systems, the characteristic that sets the endocrine system apart from the nervous system is that endocrine control tends to be faster than nervous control.

False.

True or False. Addison's disease results when the body overproduces cortisol and aldosterone.

False. | Addison's disease occurs as a result of underproduction of cortisol and aldosterone by the adrenal cortex.

True or False. Nonsteroid hormones bind to a receptor on the cell membrane of target cells but do not actually enter the target cells.

True.

True or False. Antidiuretic hormone (ADH) decreases the amount of water absorbed by the kidneys and increases the volume of urine output.

False.

True or False. Type 1 diabetes results from lack of production of insulin and Type 2 diabetes results from insensitivity of the body's cells to insulin.

True.

True or False. The secretion of TSH by the anterior pituitary gland stimulates the thymus to secrete thymosin.

False.

_________ provide the connection between the hypothalamus and the posterior pituitary, with _________ produced in the cell bodies in the hypothalamus and travelling along _______ to the posterior pituitary for _______.

Neurons...hormones...axons...storage

True or False. The thyroid glands secrete calcitonin.

True.

True or False. Lactation or the production of milk, is stimulated by the hormone LH.

False.

True or False. The hormone ACTH stimulates hormone production by the adrenal medulla.

False.

_______ hormones enter target cells and bind to intracellular receptors, whereas _______ hormones bind to cell membrane receptors and never enter the target cells.

Steroid … nonsteroid

Nonsteroid hormones usually are faster or slower acting than steroid hormones.

faster

Secretion of hormones by the anterior pituitary gland is closely regulated by the:

hypothalamus

Which two hormones most directly regulate lactation?

oxytocin and prolactin

Hormones secreted by the anterior pituitary gland control the activity of all of the following glands except:

adrenal medulla

The nervous system enables more _______ communication and signalling than does the endocrine system.

rapid

The adrenal cortex secretes hormones that may increase or decrease the inflammatory response and increase or suppress immune responses.

decrease and suppress

Glucagon causes _______ to break down to form glucose.

glycogen

Which of the following would be triggered by a drop in blood Ca2+ levels? a. increase in PTH secretion b. decrease in calcitonin secretion c. increase in ADH secretion d. both (a) and (b)

d. both (a) and (b)