Endocrine System Flashcards
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.
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.
The releasing hormones from the hypothalamus travel through the ___________ and _________ out to the anterior pituitary.
blood vessels (capillaries)…diffuse
FSH is produced in the ___________ and stimulates both _____ production and ____ development.
anterior pituitary…sperm..,egg
LH is produced in the __________ and stimulates both __________ production and ______
anterior pituitary…testosterone…ovulation
In response to the rise in glucose levels in the bloodstream following a meal, the __________ of the pancreas release insulin.
beta cells
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.
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.
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.
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.
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.
glucocorticoids
In response to stress, ACTH stimulates the adrenal cortex to secrete glucocorticoids.
_____ are the main male hormones.
Androgens
Androgens, such as testosterone, are the main male hormones
What hormone promotes water retention by the kidneys?
antidiuretic hormone (ADH)
Which hormone opposes the action of parathyroid hormone?
calcitonin
Which hormone stimulates hormone production by the ovaries and testes?
luteinizing hormone (LH)
LH stimulates hormone production by both the ovaries and testes.
Which hormone stimulates milk production?
prolactin
Prolactin, secreted by the anterior pituitary, stimulates milk production by the mammary glands.
In ___________ , target cells do not respond normally to insulin.
type 2 diabetes
In ___________ , no insulin is produced.
type 1 diabetes
In ____________ , glucose levels remain higher than normal.
both type 1 and type 2 diabetes
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.
____________ is secreted in response to low levels of blood calcium.
Parathormone
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.
You just ate about half your birthday cake. Which of the following is happening in your body?
Glucose ______, insulin ________, glucagon _________.
increases….increases…decreases
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
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.