Endocrine System EXAM***
bones kidneys intestine
Parathyroid hormone effects which of the following tissues/organs? (check all that apply)
Resorption of calcium from bone
Parathyroid hormone promotes... Decreased
It could weaken the bones by releasing calcium from the bones too fast.
Parathyroid hormone release tends to increase as we age. How could this affect our homeostasis?
are soluble in lipids. combine with protein receptor molecules. cause messenger RNA synthesis. all of the above.
Steroid hormones
cholesterol.
Steroid hormones are lipids, derived from:
false
Steroid hormones are water-soluble.
protein receptors in the cytoplasm or nucleus of the target cell.
Steroid hormones bind to
true
Steroid hormones travel in the blood attached to protein carriers.
Androgens
Stimulate pubic and axillary hair growth and sex drive in females
FALSE
TRH and TSH function together to decrease the production of T3 and T4
TRUE
TRH stimulates the secretion of TSH from the anterior pituitary
TRUE
TSH stimulates the secretion of T3 and T4 from the thyroid gland
3
The G-protein is composed of how many subunits?
Membrane bound receptor on the inside of the cell
The G-protein is found bound to the...
adrenal cortex; aldosterone
The ___ secrete(s) ___, which promotes Na+ and water retention.
parathyroid glands
The ___ secrete(s) a hormone as a response to hypocalcemia.
thyroid gland
The ___ secretes a hormone that increases the body's metabolic rate, promotes alertness , quickens reflexes, and stimulates the fetal nervous system.
anterior pituitary
The ____________ secretes FSH and LH, which regulate the production of reproductive hormones by the ovaries and the testes.
true
The alpha subunit can remain separated from the beta and gamma subunits as long as the ligand remains bound to the membrane bound protein.
G-protein ; adenylyl cyclase
The binding of epinephrine to its receptor activates ________ which in turn activates ________.
G protein.
The binding of epinephrine to its receptor activates a(n)
negative
The concentration of most hormones is controlled by _____ feedback.
TRUE
The conversion of ATP into cAMP is catalyzed by the enzyme adenylyl cyclase.
Corticosteroids
The cortex of the suprarenal (adrenal) glands produces...
insulin and glucagon
The endocrine portion of the pancreas produces...
phosphates
The enzyme a-kinase adds ________ to proteins.
glucagon
The hormone that increases the rate of glycogen breakdown and glucose release by the liver is:
calcitonin.
The hormone that stimulates calcium deposition into bone is
the adenohypophysis with the hypothalamus.
The hypophyseal portal system connects
Adenohypophysis
The hypothalamo-hypophyseal portal system connects the hypothalamus to the...
producing hypothalamic-releasing hormones and hypothalamic-inhibiting hormones.
The hypothalamus controls anterior pituitary hormone release by
Regulates most endocrine functions of the body
The hypothalamus is sometimes referred to as the "master control center" of the endocrine system because it...
neurohormones, releasing, inhibiting
The hypothalamus secretes _____, which are classified as _____ hormones if they increase the secretion of an anterior pituitary hormone, or _____ hormones if they decrease the secretion of an anterior pituitary hormone
neurohormones, releasing, inhibiting
The hypothalamus secretes _____, which are classified as _____ hormones if they increase the secretion of an anterior pituitary hormone, or _____ hormones if they decrease the secretion of an anterior pituitary hormone.
a projection of the hypothalamus from which the pituitary gland hangs.
The infundibulum is
Peptide hormones bind to receptors on the cell surface whereas steroid hormones bind to intracellular receptors
The main difference between the modes of action of peptide hormones and steroid hormones is that
cortisol
The major hormone responsible for mediating the body's response to stress is
Epinephrine & norepinephrine; "fight or flight"
The medulla of the suprarenal gland secretes _____________ to enhance the ______________ response of the sympathetic nervous system.
Type 1 diabetes
The metabolic condition called ___________ results from the destruction of the beta cells in the pancreas due to an autoimmune response
Type 1 diabetes
The metabolic condition called ___________ results from the destruction of the beta cells in the pancreas due to an autoimmune response.
stimulation of mRNA transcription.
The mode of action of steroid hormones involves
Located between the duodenum and spleen, just inferior to the stomach
The pancreas is...
enzyme-rich pancreatic juice
The pancreatic acinar cells secrete...
posterior
The parathyroid glands are usually located on which surface of the thryoid gland?
hypothalamus.
The part of the brain that some consider to be a "master control center" of the endocrine system is the:
hypophyseal fossa
The pituitary gland is located in the...
FALSE
The posterior pituitary produces both inhibiting and releasing hormones.
stimulate glucocorticoid release from the adrenal glands.
The primary function of adrenocorticotropic hormone (ACTH) is to:
Aldosterone; sodium and potassium ions
The principal mineralocorticoid is _____________ that helps regulate levels of _____________ in the blood and body fluids.
true
The second messenger cAMP is made from ADP.
adenylyl cyclase.
The second messenger cAMP is synthesized by the enzyme
kidneys
The suprarenal (adrenal) glands are located superior to which organ(s)?
true
The thyroxine-hormone receptor complex increases the level of transcription of specific genes.
oxytocin and antidiuretic hormone.
The two hormones released from the posterior pituitary are:
the pineal gland
This figure shows the major organs of the endocrine system. What does "1" represent?
3
This figure shows the major organs of the endocrine system. Which structure secretes growth hormone (GH or somatotropin)?
melatonin
This hormone plays an important role in synchronizing physiological function with the cycle of daylight and darkness.
immune, thymus
Thymosin is important for the development of the __________ system, and is released from the _________.
Growth hormone (GH)
Thyroid hormone stimulates the anterior pituitary to release...
thyroglobulin
Thyroid hormone synthesis involves secretion of a glycoprotein called ___________ by the follicular cells
thyroglobulin
Thyroid hormone synthesis involves secretion of a glycoprotein called ___________ by the follicular cells.
regulate gene transcription.
Thyroid hormones bind to receptors which
true
Thyroxine is brought to target cells via a protein-carrier.
The amino acid tyrosine
To synthesize thyroid hormones, iodine is attached to
hormones secreted from Thyroid
Triiodothyronine (T3) Thyroid hormone (tetaiodothyroinine) (T4) Thyroid hormone (T3 T4 collectively TH)
Intracellular proteins
Ultimately, what is responsible for aldosterone's effects on a cell?
GTP replacing GDP
What activates the alpha subunit of the G-protein?
inhibits insulin inhibits glucagon
What are the functions of the pancreatic hormone somatostatin? (check all that apply)
The kidneys and blood vessels
What are the two main targets of antidiuretic hormone (ADH)?
Ligand binding to the membrane bound receptor
What causes the change in conformation of the G-protein resulting in separation from the membrane bound receptor?
Chief (principal) cell
What cell in the parathyroid gland secretes parathyroid hormone?
Tyrosine
What is the dominate amino acid in thyroglobulin?
Isthmus
What is the name of the narrow band of tissue connecting the right and left lobes of the thyroid gland?
the presence of a receptor for that particular hormone
What makes a cell responsive to a particular hormone?
The hormone binds to an appropriate receptor on (in) the target cell
What occurs when hormones reach their target cells?
Low blood calcium level
What stimulates the secretion of parathyroid hormone from the parathyroid gland?
paracrine
When a chemical messenger helps initiate an inflammatory response by causing cellular changes in neighboring cells, it is demonstrating ___________ signaling.
insulin; lower blood glucose level and promote formation of glycogen
When a person's blood glucose level rises the pancreas releases ____ in order to ____.
the first messenger.
When the effects of water-soluble hormones on their target cells are considered, the hormone is considered:
Follicle-stimulating hormone and luteinizing hormone
Which hormones are collectively called the gonadotropins?
Decrease blood glucose levels
Which is not a function of epinephrine and norepinephrine
Decrease blood glucose levels
Which is not a function of epinephrine and norepinephrine?
anterior pituitary
Which lobe of the pituitary is larger and secretes more hormones?
cortisol
Which of the following is NOT a polypeptide or glycoprotein hormone
MSH
Which of the following is NOT a tropic hormone?
Both the T3 and T4 forms enter target cells.
Which of the following statements about thyroxine is TRUE?
It is water-insoluble and lipophilic
Which of the following statements about thyroxine is TRUE? It
beta cells:insulin
Which pancreatic islet cell type is correctly matched with its product?
hypothalamo-hypophyseal tract.
Within the infundibulum, the axons from neurons extending into the posterior pituitary are kno
hypothalamo-hypophyseal tract.
Within the infundibulum, the axons from neurons extending into the posterior pituitary are known as the:
more widespread and long-lasting effects.
compared to the nervous system, the endocrine system has:
Hypothalamic - hypophyseal tract
connects hypothalamus and posterior pituitary
increased calcitonin levels result in __________ osteoclast activity in the bones, resulting in ____________ blood calcium levels.
decrease, decrease
This is the last step in the sequence of events happening when cyclic AMP acts as a second messenger.
enzymes are activated or deactivated by the action of protein kinases
true
glucocorticoids are hormones that stimulate metabolism of lipids and proteins, and help regulate glucose levels in the blood.
Follicle-stimulating hormone and luteinizing hormone
hormones that are collectively called the gonadotropins
Endocrine system consists of
hypothalamus pituitary gland thyroid parathyroid adrenal glands pineal glands reproductive glands pancreas
cortisol
increases blood glucose levels; suppresses the immune system
Tropic hormones stimulate the secretion of other hormones from target tissues - true Tropic hormones are secreted by the anterior pituitary gland - true Tropic hormones are secreted by the posterior pituitary gland - false Tropic hormones can control the growth of target tissues - true
indicate whether each is true or false with regards to tropic hormones. Tropic hormones stimulate the secretion of other hormones from target tissues Tropic hormones are secreted by the anterior pituitary gland Tropic hormones are secreted by the posterior pituitary gland Tropic hormones can control the growth of target tissues
false
lipophilic hormones and thyroid hormone are transported to their target cells free in the plasma.
G-proteins
many membrane bound receptors produce responses through g-proteins
decreased; decreased
ncreased calcitonin levels result in __________ osteoclast activity in the bones, resulting in ____________ blood calcium levels.
hormones secreted from Adrenal cortex
norepinephrine (NE)
Gluconeogenesis is:
production of glucose from noncarbohydrate molecules, and it occurs when blood glucose is low.
Endo
secretes into bloodstream
Exo
secretes into duct
The thyroid gland
secretes large amounts of tetraiodothyronine and small amounts of triiodothyronine.
Thymus
secretes several hormones that stimulate the development of lymphatic organs and regulates development and activity of T cells (white blood cells).
tropic hormones
stimulate certain endocrine glands to secrete hormones.
Adrenocorticotropic hormone (ACTH)
target tissue: adrenal cortex stimulates: release of corticosteroids -primary function is to stimulate glucocorticoid release from the adrenal glands.
Follicle-stimulating hormone (FSH)
target tissue: gonads stimulates: gamete production
Prolactin
target tissue: mammary gland stimulates: milk synthesis -Milk production by the mammary glands is initiated and maintained by
Growth hormone (GH)
target tissue: thyroid gland stimulates normal development & secretory activity of thyroid -enhances the movement of amino acids into cells -increases the rate of protein synthesis -ncreases the rate of fat metabolism
melanocyte-stimulating hormones (MSH)
target tissue:melanocytes stimulates: melanin production
Thyrotropin-releasing hormone
targets the anterior pituitary (adenohypophysis)
Thyroid gland (TSH)
targets: adrenal cortex stimulates:release of corticosteroids -secretes a hormone that increases the body's metabolic rate, promotes alertness , quickens reflexes, and stimulates the fetal nervous system
Luteinizing hormone (LH)
targets: gonads stimulates: release of ova & progesterone production in ovaries, testosterone synthesis & sperm cell development in testes
thymus
the ___ secretes several hormones that stimulate the development of lymphatic organs and regulates development and activity of T cells (white blood cells).
calcitonin
the hormone that stimulates calcium deposition into bone is
The release of hormones from the adrenal medulla is stimulated by:
the sympathetic division of the autonomic nervous system.
Most circulating T3 and T4 travel in the blood bound to _____________.
thyroxine-binding globulin
cortisol
which of the following is NOT a polypeptide or glycoprotein hormone cortisol glucagon antidiuretic hormone parathyroid hormone
Both the T3 and T4 forms enter target cells.
which of the following statements about thyroxine is TRUE?
oxytocin
which of the following stimulates uterine contractions during childbirth and milk release during lactation?
Gonads - Ovaries
- endocrine & exocrine glands
Gonads - Testies
- endocrine & exocrine glands
Pancreas
- endocrine & exocrine glands
Hypothalamus
- endocrine gland with neutral functions -regulates pituitary gland through hormones and APs (1. anterior pituitary and 2. posterior pituitary) -Hormones secreted by the posterior pituitary are synthesized here
Two forms of transport & excretion of hormones: 1. Water soluble hormones/ hydrophilic hormones:
- hydrophilic - mixes with or dissolves in water - does NOT need another molecule to transport - transports in short duration & rapid onset - quickly broken down by enzymes or removed by kidneys EX. blood is mostly water, free float -proteins, E & NE -membrane bound/cell surface receptors bind to these hormones
2. Oxytocin
- secreted by posterior pituitary gland - promotes uterine contractions during birth & milk release during lactation -stimulates uterine contractions during childbirth and milk release when an infant is nursing
cortisol
-Increases blood glucose levels; suppresses the immune system -is secreted by the adrenal cortex and assists in the maintenance of normal glucose regulation.
Two main chemical classes of hormones: 1. Protein group
-Proteins (made of amino acids) -polypeptides (made of chain of amino acids) -glycoproteins (protein + a carbohydrate) -AA derivatives (dopamine, epi)
Receptors
-Target tissues have these for particular hormones -cells must have in order to respond to hormones -specific TWO types: 1. membrane bound 2. intracellular bound
melatonin
-This hormone plays an important role in synchronizing physiological function with the cycle of daylight and darkness
Chemical messengers: Paracrines
-act locally on different cells -growth factors, clotting factors & histamines -ex. cut on finger, damaged tissue triggers histamines
Chemical messengers: Autocrines
-act locally on same cells that secrete them -porstaglandins, thromboxanes, prostacyclins & leukotrienes
Parathyroid
-has the most profound direct effect on the decrease of bone mass, increased resorption of bone, in response to lowered plasma calcium levels -secrete(s) a hormone as a response to hypocalcemia.
hyperaldosteronism
-high levels of aldosterone have a condition known as hyperaldosteronism -can cause high blood pressure, low potassium levels and an abnormal increase in blood volume because of the way the hormone affects the body
Endocrine system
-influences metabolic activities of ells via hormones -acts with nervous system to control all body systems
RECEPTORS: 1. membrane bound receptors: AKA cell surface receptors
-located across the span of plasma membrane -bind to water-soluble (hydrolipic or large molecular weight molecules) -linked to second-mesanger on other side of plasma membrane -can make changes inside the cell membrane bound receptors ⇨ second messenger systems activated ⇨ activate g proteins open or close ion channels & increase or decrease activity of existing enzymes ⇨ cell response
RECEPTORS: 2. intracellular receptors:
-located in the cytoplasm or nucleus of cell -bind to lipid-soluble/ hydrophobic hormones -ligated molecules that can travel acres plasma membrane -slow acting -DNA to ⇨ RNA (transcription) ⇨ protein synthesis - new enzyme after cell physiology (response of target cell to hormones) hormone⇨ intracellular receptors⇨ activate or suppress genes ⇨ increase or decrease production of new proteins or enzymes⇨ cell response
Hormones
-long-distance chemical signals -travel/transport in the blood/ lymph -secreted by endocrine hands/tissues into ISF & diffuse into blood -range from seconds to hours and has long term/prolonged effects -secretion of hormones controlled by negative feedback
Addison's Disease
-low levels of aldosterone -a disease that causes a general loss of adrenal function -patients experience low blood pressure, increased potassium levels and lethargy.
Pituitary gland: 1. Anterior pituitary AKA adenohypophysis
-makes 7 hormones: 1. Growth hormone (GH) 2. Thyroid-stimukating hormone (TSH) 3. Adrenocorticotropic hormone (ACTH) 4. melanocyte-stimulating hormones (MSH) 5. Luteinizing hormone (LH) 6. follicle-stimulating hormone (FSH) 7. Prolactin -controlled by hypothalamic hormones -targeted by Thyrotropin-releasing hormone -secretes FSH and LH, which regulate the production of reproductive hormones by the ovaries and the testes.
Aldosterone
-produced by the zona glomerulosa of the adrenal cortex in the adrenal gland -promotes the homeostasis of ions by causing the kidneys to conserve sodium and excrete potassium -body's ability to regulate blood pressure -causes the bloodstream to re-absorb water with the sodium to increase blood volume -high levels of aldosterone have a condition known as hyperaldosteronism -Increase sodium reabsorption in the kidneys -promotes the homeostasis of ions by causing the kidneys to conserve sodium and excrete potassium.
Hypophyseal portal system
-releasing and inhibiting hormones -travel to anterior pituitary via hypophyseal portal system -inhibit or stimulate hormone production in anterior pituitary
cAMP second messenger mechanism
-requires cellular energy -short lived effect 1. hormones (first messenger) binds to receptor 2. receptor activates G proteins 3. G protein activates an enzyme called adenylate cyclase which converts ATP to cyclic AMP (second messenger) 4. cAMP activates kinases, enzymes that phosphorylate other enzymes, activating some & inactivating others 5. activated enzymes produce cells response
1.Antiduietic hormone (ADH) AKA Vasopressin
-secreted by posterior pituitary gland -targets kidneys -promotes water retention by kidneys -alcohol inhibits ADH (lose water, become dehydrated) -secreted by nerve fibers in the posterior lobe of the pituitary gland
Pituitary gland
-secretes 9 hormones & regulates numerous body functions & other endocrine glands -composed of TWO structures with separate functions: 1. anterior pituitary 2. posterior pituitary
Two main chemical classes of hormones: 2. Lipid group
-steroids (includes vitamin D) -FA derivatives (fatty acid derivatives -3 major fat/lipids: steroids triglycerides & eicosanoids phospholipds
cholecystokinin
-stimulates contraction of the gall bladder and release of enzyme-rich pancreatic juice
Tropic hormone
-stimulates secretion of another hormones -ex. thyroid hormone
Pituitary gland: 2.Posterior pituitary AKA neurohypophysis
-stores and secretes 2 polypeptide hormones (but DOES NOT produce them): 1.Antiduietic hormone (ADH) 2. Oxytocin - connects to hypothalamus by infundibulum
Two forms of transport & excretion of hormones: 2. Lipid soluble : AKA hydrophobic lipophilic fat-soluble hormones
-transports by proteins (albumins & globulins) -they are bound to a carrier so they are not quickly removed from blood & have prolonged effects - cannot free float & hates water - Thyroid hormones behave like lipid soluble hormones, but is not a lipid -intracellular receptors bind to these hormones
directly causing protein synthesis.
A steroid hormone acts on a target cell by
hypothyroidism
Absence of iodine in the diet leads to
hormones secreted from Anterior pituitary gland
Adrenocorticotropic hormone (ACTH) Follicle-stimulating hormone (FSH) Growth hormone (somatotropin)(GH) Luteinizing hormone (LH) Prolactin (PRL) Thyroid-stimulating hormone (TSH)
Moves into the nucleus and binds to DNA
After aldosterone binds to an intracellular receptor, the receptor complex...
FALSE
Aldosterone cannot diffuse directly through the plasma membrane.
lipid-soluble hormone
Aldosterone is a...
glucagon
Alpha cells of the pancreas secrete the hormone _________.
kidneys
Antidiuretic hormone (ADH) targets the
increases water retention from renal tubules
Antidiuretic hormone (known as ADH or vasopressin)...
cortisol rise
As a result of the general stress response, blood concentrations of epinephrine
Hypothalamus: Antidiuretic hormone (ADH)
As an example of hormonal communication, when osmoreceptors of the _______________ detect dehydration, a signal to the posterior pituitary gland causes the release of _________________.
hormones secreted from hypothalamus
Corticotropin-releasing hormone (CRH) Growth hormone-releasing hormone (GHRH) Gonadotropin-releasing hormone (GnRH) Prolactin-inhibiting hormone (dopamine) (PIH) Thyrotropin-releasing hormone (TRH)
increase
Damage to the liver might impair enzymatic degradation of some hormones. The levels of such hormones in the blood would therefore be expected to:
increase, decrease
Elevated levels of T3 and T4 __________ metabolic rate, while decreased levels of T3 and T4 _________ metabolic rate.
target
Endocrine glands secrete hormones into the bloodstream, where they travel to specific sites called _____ tissues.
false
Epinephrine has to cross the cell membrane to bind to its receptor in the cytoplasm.
antagonistically
Glucagon and insulin work _________ on blood glucose levels.
TRUE
Glucocorticoids are hormones that stimulate metabolism of lipids and proteins, and help regulate glucose levels in the blood.
production of glucose from noncarbohydrate molecules, and it occurs when blood glucose is low
Gluconeogenesis is:
The blood stream
Hormone molecules are typically transported to the target cells by...
2-3 months
How long can iodinated thyroglobulin be stored in a thyroid follicle lumen?
2-6
How many parathyroid glands are there?
release hormones
In general, sensory input to a portion of the neuroendocrine system causes...
Binds to an intracellular aldosterone receptor
In the cytoplasm of a cell, aldosterone...
Thyroid follicle lumen
In the thyroid gland, where are iodide molecules converted to iodine?
aldosterone
Increase sodium reabsorption in the kidneys
TRUE
Increased blood levels of T3 and T4 inhibit TRH and TSH secretion
glucagon
Increased breakdown of glycogen; increased blood glucose levels
glucagon
Increased breakdown of glycogen; increased blood glucose levels -Alpha cells of the pancreas secrete the hormone -the hormone that increases the rate of glycogen breakdown and glucose release by the liver
insulin
Increased uptake of glucose and amino acids
insulin
Increased uptake of glucose and amino acids -secreted by the beta cells of the pancreas -causes an in screase in glycogenesis in the liver and an increase in lipogenesis in adipose.
Indicate whether each is true or false with regards to tropic hormones. Tropic hormones stimulate the secretion of other hormones from target tissues - TRUE Tropic hormones are secreted by the anterior pituitary gland - true Tropic hormones are secreted by the posterior pituitary gland - false Tropic hormones can control the growth of target tissues - true
Indicate whether each is true or false with regards to tropic hormones. Tropic hormones stimulate the secretion of other hormones from target tissues Tropic hormones are secreted by the anterior pituitary gland Tropic hormones are secreted by the posterior pituitary gland Tropic hormones can control the growth of target tissues
increase, increase
Insulin causes a(n) _______ in glycogenesis in the liver and a(n) _______ in lipogenesis in adipose.
bind to DNA and initiate transcription.
Lipid-soluble hormones, such as progesterone, exert their effects by forming hormone-receptor complexes that:
false
Lipophilic hormones and thyroid hormone are transported to their target cells free in the plasma.
thyroxine-binding globulin
Most circulating T3 and T4 travel in the blood bound to
Nervous system VS Endocrine
NERVOUS: -uses nerurotransmitters as messengers ENDOCRINE: - uses hormones as messengers - long distance
thyroid hormone (TH) targets the anterior pituitary.
Negative feedback inhibition occurs when
antidiuretic hormone.
Nerve fibers in the posterior lobe of the pituitary gland secrete
hormones secreted from Posterior pituitary gland
Oxytocin (OT) Antidiuretic hormone (ADH)
hormones secreted from Parathyroid
Parathyroid hormone (parathormone PTH)
the heart
atrial natriuretic peptide is secreted by the
Two main chemical classes of hormones:
1. protein group 2. lipid group
Two forms of transport & excretion of hormones:
1. water-soluble hormones 2. lipid-solubl hormones + thyroid hormones
ghrelin
A hormone produced by the stomach called ____ ,that signals hunger, is an antagonistic hormone to leptin that signals satiety.
causing synthesis of a second messenger.
A nonsteroid hormone acts on a target cell by
Estrogen
__ enters a target cell's nucleus and acts directly on the genes.
estrogen
__ enters a target cell's nucleus and acts directly on the genes.
growth hormone
___ has more target cells in the body than any of the others.
The infundibulum
___ is a projection of the hypothalamus from which the pituitary gland hangs.
Glucagon
___ is synthesized in the rough endoplasmic reticulum.