Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
A&PII - Ch 16
Endocrine System
| Question | Answer |
|---|---|
| body system that includes internal organs that secrete hormones | endocrine system |
| endocrine system influences __ activity by means of hormones | metabolic |
| steroidal or amino acid–based molecules released to the blood that act as chemical messengers to regulate specific body functions | hormones |
| binding of hormones to cellular receptors initiates responses that typically occur after __ __ of seconds or even days | lag period |
| once initiated responses to hormone receptor sites tends to be much __ __ than those induced by nervous system | more prolonged |
| reproduction; growth & development; maintenance of electrolyte, water, & nutrient balance of blood; regulation of cellular metabolism & energy balance; & mobilization of body defenses | major processes controlled & integrated by endocrine system |
| endocrine system orchestrates processes that go on for | relatively long periods or even continuously |
| scientific study of hormones & endocrine organs | endocrinology |
| compared with other organs of the body the endocrine glands are | small & unimpressive |
| endocrine organs are not __ __ in the body | grouped together |
| endocrine organs are __ __ throughout the body | widely scattered |
| endocrine glands are also called | ductless glands |
| endocrine glands released their hormones into | surrounding tissue fluid |
| within | endo- |
| to secrete | -crine |
| endocrine glands have __ vascular & lymphatic drainage that receives their hormones | rich |
| most of hormone-producing cells in endocrine glands are arranged in __ & __ networks | cords; branching |
| cords & branching networks are a situation that __ contact between endocrine glands & capillaries surrounding them | maximizes |
| includes pituitary, thyroid, parathyroid, adrenal, & pineal glands | endocrine glands |
| considered a neuroendocrine organ because, along with its neural functions, it produces & releases hormones | hypothalamus |
| pancreas, gonads, & placenta, along with performing other functions, | contain endocrine tissue |
| endocrine function of adipose cells release | leptin |
| endocrine function of thymus is release | thymic hormones |
| are found in walls of small intestine, stomach, kidneys, & heart | hormone-producing cells |
| hormones are long-distance chemical signals that travel in __ throughout the body | blood/lymph |
| chemicals that exert their effects on same cells that secrete them | autocrines |
| also act locally but affect cell types other than those releasing the chemicals | paracrines |
| certain prostaglandins released by smooth muscle cells cause those smooth muscle cells to contract making it a(n) | autocrine |
| released by one population of pancreatic cells inhibits release of insulin by a different population of pancreatic cells making it a(n) | paracrine |
| synthesize hormones identical to those made in normal endocrine glands in excess/uncontrolled fashion leading to problems due to hormone-mediated pathology | certain tumor cells, such as lung/pancreatic cancer |
| most hormones are __ __ based | amino acid |
| simple amino acid derivatives | amines & thyroxine |
| short chains of amino acids | peptides |
| long polymers of amino acids | proteins |
| group of chemical substances including certain hormones & cholesterol; fat soluble & contain little oxygen | steroid |
| only gonadal & adrenocortical hormones are | steroids |
| biologically active lipids are released by nearly all cell membranes; includes leukotrienes & prostaglandins | eicosanoids |
| signaling chemicals that mediate inflammation & some allergic reactions | leukotrienes |
| have multiple targets & effects, ranging from raising blood pressure & increasing expulsive uterine contraction of birth to enhancing blood clotting, pain, & inflammation | prostaglandins |
| because effects of eicosanoids are typically highly localized, they generally act as paracrines/autocrines instead of | true hormones |
| true hormones influence __ targets | distant |
| all major hormones circulate to __ __ tissues | virtually all |
| influences activity of only certain tissue cells, referred to as its target cells | given hormone |
| hormones bring about their characteristic effects on target cells by __ cell activity, either decreasing/increasing rates of normal cellular processes | altering |
| hormonal stimulus typically alters plasma membrane permeability/potential (or both) by | opening/closing ion channels |
| hormonal stimulus typically __ __ of proteins or regulatory molecules (such as enzymes within cell) | stimulates synthesis |
| hormonal stimulus typically activates or deactivates __ | enzymes |
| hormonal stimulus typically stimulates | mitosis |
| hormones act at receptors in the plasma membrane when they are | water-soluble hormones |
| water-soluble hormones are all amino acid-based hormones except for | thyroid hormone |
| water-soluble hormones are coupled via regulatory molecules called __ to one/more intracellular 2nd messengers which mediate target cell's response | G proteins |
| act on intracellular receptors, which directly activate genes | lipid-soluble hormones |
| lipid-soluble hormones include | steroid & thyroid hormones |
| receptor for water-soluble hormones must be in __ __ since these hormones cannot enter cell | plasma membrane |
| receptor for lipid-soluble steroid & thyroid hormones are __ cell | inside |
| intracellular molecule generated by the binding of a chemical (hormone or neurotransmitter) to a plasma membrane receptor; mediates intracellular responses to the chemical messenge | second messengers |
| with exception of thyroid hormone, all __ __ hormones exert their signaling effects through intracellular second messengers | amino acid-based |
| intracellular second messenger that mediates the effects of the first (extracellular) messenger (hormone or neurotransmitter); formed from ATP by a plasma membrane enzyme (adenylate cyclase) | cyclic AMP |
| cyclic AMP is used by __ & __ receptors | neurotransmitters; olfactory |
| cyclic AMP mechanism involves interaction of __ plasma membrane components to determine intracellular levels of cyclic AMP | three |
| cyclic AMP | cAMP |
| three plasma membrane components to determine intracellular levels of cAMP | hormone receptor, G protein, & effector enzyme |
| hormone bind receptor on plasma membrane | 1st step of cAMP mechanism |
| receptor activates G protein | 2nd step of cAMP mechanism |
| when receptor activates G protein, hormone binding causes receptor to __ __, allowing it to bind a nearby inactive G protein | change shape |
| when receptor activates G protein, it is activates as __ bound to it is displaced by high-energy compound __ | GDP (guanosine diphosphate); GTP (guanosine triphosphate) |
| once activated (cAMP) G protein behaves like a light switch, off when __ is bound to it and on when __ is bound | GDP; GTP |
| G protein activate adenylate cyclase | 3rd step of cAMP mechanism |
| during cAMP mechanism, activated G protein (moving along membrane) binds to effector enzyme | adenylate cyclase |
| G protein that stimulates adenylate cyclase | Gs |
| G protein that inhibits adenylate cyclase | Gi |
| during cAMP mechanism, eventually GTP bound to G protein is __ to GDP, & G protein becomes inactive once again | hydrolyzed |
| during cAMP mechanism, G protein cleaves terminal phosphate group off GTP in much same way that ATPase enzymes | hydrolyze ATP |
| adenylate cyclase converts ATP to cyclic AMP | 4th step of cAMP mechanism |
| during cAMP mechanism, for as long as activated Gs is bound to it, adenylate cyclase generates second messenger cAMP from | ATP |
| cyclic AMP activate protein kinase | 5th step of cAMP mechanism |
| cAMP, which is free to diffuse throughout cell, triggers __ of chemical reactions by activating protein kinase | cascade |
| enzymes that phosphorylate various proteins, many of which are other enzymes | protein kinase |
| because __ activates some proteins and inhibits others (during cAMP) a variety of processes may be affected in same target cell at same time | phosphorylation |
| type of intracellular enzymatic cascade during cAMP has a huge __ effect | amplification |
| each activated adenylate cyclase generates large numbers of cAMP molecules, and a single kinase enzyme can catalyze | hundreds of reactions |
| as cAMP mechanism reaction cascades through 1 enzyme intermediate after another, number of product molecules __ __ at each step | increases dramatically |
| depends on type of target cell, specific protein kinase it contain, & substrates within that cell available for phosphorylation by protein kinase | sequence of reaction set into motion by cAMP |
| binding of thyroid-stimulating hormone promotes synthesis of thyroid hormone | thyroxine |
| in liver, binding of glucagon activates enzymes that breakdown glycogen, releasing | glucose to blood |
| since some G proteins inhibit rather that activate adenylate cyclase, reducing cytoplasmic concentration of cAMP, even slight changes in levels of __ __ can influence target cell's activity | antagonistic hormones |
| epinephrine, ACTH, FSH, LH, glucagon, PTH, TSH, & calcitonin are all hormones that | act via cAMP mechanisms |
| action of cAMP persists only briefly because molecules is rapidly degraded by intracellular | enzyme phosphodiesterase |
| any of a class of enzymes that catalyze the cleaving of phosphodiester bonds, such as those between nucleotides in nucleic acids, to produce smaller nucleotide units | phosphodiesterase |
| because of amplification effect of cAMP mechanisms, most hormones need to be present __ __ to cause desired results | only briefly |
| in PIP2-calcium signaling mechanism, intracellular calcium ions act as | final mediator |
| phosphatidyl inositol bisphosphate | PIP2 |
| enzyme called phospholipase C splits plasma membrane phospholipid called PIP2 into diacylglycerol (DAG) and inositol trisphosphate (IP3) | PIP2-calcium signaling mechanism |
| in PIP2-calcium signaling mechanism, ___ activates protein kinase C which triggers responses within target cell | diacylglycerol (DAG) |
| in PIP2-calcium signaling mechanism, __ __ releases Ca2+ from intracellular storage sites | inositol trisphosphate (IP3) |
| PIP2-calcium signaling mechanism, __ __ takes on second-messenger role, either by directly altering activity of specific enzymes & channels or by binding to intracellular regulatory protein calmodulin | liberated Ca2+ |
| in PIP2-calcium signaling mechanism, once Ca2+ binds to calmodulin it activates enzymes that __ cellular response | amplify |
| thyrotropin-releasing hormone (TRH), antidiuretic hormone (ADH), gonadotropin-releasing hormone (GnRH), oxytocin, & epinephrine are all hormones known to act on their target cells via | PIP2 mechanism |
| insulin & other growth factors work __ second messengers | without |
| tyrosine kinase enzyme that is activated by autophosphorylation when insulin binds | insulin receptor |
| activated insulin receptor provides docking sites for intracellular __ proteins | relay |
| initiate series of protein phosphorylations that triggers specific cell responses | relay proteins |
| in certain instances, any of second messengers & hormone receptor itself can cause changes in | intracellular Ca2+ levels |
| thyroid hormone receptors are __ bound to DNA even in absence of thyroid hormone | always |
| for steroid & thyroid hormones, activated receptor-hormone complex makes way to nuclear chromatin and then binds to region of DNA; this interaction "turns on" a gene that prompts transcription of DNA to produce | messenger RNA (mRNA) |
| for steroid & thyroid hormones, once mRNA produced, it is then translated on __ __, producing specific protein molecules | cytoplasmic ribosomes |
| protein molecules produced by mRNA include enzymes that promote metabolic activities induced by that particular hormone & in some cases promote synthesis of structural proteins or proteins to be transported from target cell | for steroid & thyroid hormones |
| for steroid & thyroid hormones, in absence of hormone receptors are bound up in | receptor-chaperonin complexes |
| receptor-chaperonin complexes that takes place in absence of steroid & thyroid hormones, keep receptors from binding to DNA and may | protect them from proteolysis |
| hydrolytic breakdown of proteins into simpler, soluble substances such as peptides and amino acids, as occurs during digestion | proteolysis |
| when steroid & thyroid hormones are present receptor-chaperonin complexes __ allowing hormone-bound receptor to bind to DNA & influence transcription | dissociate |
| in order for target cell to respond to hormone, cell must have __ __ receptors on its plasma membrane or in it interior to which that hormones can bind | specific protein |
| receptors for ACTH are normally found on certain cell of | adrenal cortex |
| is principal hormone stimulating cellular metabolism, and nearly all body cells have its receptors | thyroxine |
| responds to hormone binding by prompting cell to perform, or turn on, some gene-determined preprogrammed function | hormone receptor |
| hormones are molecular __ rather than informational molecules | triggers |
| target cell activation by hormone-receptor interaction __ __ on blood levels of hormone, relative numbers of receptors for that hormone on target cell, & affinity of binding btwn response to various stimuli & changes within body | depends equally |
| for a given level of hormone in the blood, a large number of __ receptors produce a pronounced hormonal effect | high-affinity |
| for a given level of hormone in the blood, a smaller number of __ receptors results in reduced target cell response or outright endocrine dysfunction | low-affinity |
| receptors are __ structures | dynamic |
| phenomenon in which target cells form more receptors in response to rising blood levels of specific hormone to which they respond | up-regulation |
| prolonged exposure to high hormone concentration desensitizes target cells, sot that they respond less vigorously to hormonal stimulation | down-regulation |
| down-regulation involves loss of receptors & prevents target cells from overreacting to | persistently high hormone levels |
| hormones influence number & affinity not only of their own receptors but also receptor that | respond to other hormones |
| progesterone induces loss of estrogen receptors in uterus, this __ estrogen's actions; while estrogen causes same cells to produce more progesterone receptors, __ ability to respond to progesterone | antagonizing; enhances |
| hormones circulate through the blood as | free or bound to protein carrier |
| lipid-soluble hormones travel in bloodstream attached to | plasma proteins |
| __ of a circulating hormone in blood at any time reflects it rate of release & speed at which it is inactivated & removed from body | concentration |
| some hormones are rapidly degraded by __ in their target cells | enzymes |
| most hormones are removed from the blood by | kidneys or liver |
| most hormone breakdown products are excreted from body in | urine or feces |
| length of time for a hormone's blood level to decrease by half; varies from fraction of minute to a week | half-life |
| __ hormones exhibit shorted half-lives | water-soluble |
| is limited, ranging from 10 seconds to several hours | duration of hormone action |
| because of many variations, hormonal __ __ must be precisely & individually controlled to meet continuously changing needs of body | blood levels |
| situation when 1 hormone cannot exert its full effects without another hormone being present | permissiveness |
| permissive effect for normal timely development of reproductive structures (along with reproductive hormones) | thyroid hormone |
| occurs in situation where more than 1 hormones produces same effects at target cell & their combined effects are amplified | synergism |
| glucagon & epinephrine cause liver to release glucose to blood; when they act together amount of glucose released is about 150% of what is released when each hormone | acts alone |
| when one hormone opposes action of another hormone | antagonism |
| may compete for same receptors, act through different pathways, or even cause down-regulation of receptors for antagonistic hormone | antagonistic hormone |
| synthesis & release of most hormones are regulated by | negative feedback system |
| major types of stimuli trigger endocrine glands to manufacture & released their hormones | humoral, neural, & hormonal |
| endocrine glands secrete their hormones in direct response to changing blood levels of certain critical ions & nutrients | humoral stimuli |
| humoral stimuli are __ endocrine controls | simplest |
| hormones released in response to humoral stimuli include | PTH, insulin, & aldosterone |
| nerve fibers stimulate hormone release | neural stimuli |
| sympathetic nervous system stimulation of adrenal medulla to release catecholamines during periods of stress | example of neural stimuli |
| most anterior pituitary hormone release is regulated by releasing/inhibiting hormones by | the hypothalamus |
| many anterior pituitary hormones stimulate other endocrine to | release their hormones |
| hormonal stimuli promote rhythmic hormone release, with hormone blood levels rising & falling in a specific pattern | hypothalamic-pituitary-target endocrine organ feedback loop |
| hormonal, humoral, & neural stimuli are __ factors that affect endocrine system | turn-on |
| feedback inhibition & others are __ factors that affect endocrine system | turn-off |
| in the body the __ system makes certain adjustment to maintain homeostasis by overriding normal endocrine controls | nervous |
| 90-110mg/100ml of blood is the __ range of glucose levels in the blood | normal |
| neuroendocrine gland located beneath the brain that serves a variety of functions including regulation of gonads, thyroid, adrenal cortex, lactation, and water balance | pituitary gland |
| pituitary gland is also known as | hypophysis |
| stalk of tissue that connects the pituitary gland to the hypothalamus superiorly | infundibulum |
| composed largely of pituicytes and nerve fibers | posterior pituitary |
| glia-like supporting cells | pituicytes |
| hormones secreted by neurons; released by posterior pituitary | neurohormones |
| posterior pituitary is a(n) __ area | hormone-storage |
| posterior pituitary plus infundibulum; portion of the pituitary gland derived from the brain | neurohypophysis |
| anterior pituitary; the glandular part of the pituitary gland | adenohypophysis |
| aterial blood is delivered to pituitary via __ branches of internal carotid arteries | hypophyseal |
| veins leaving pituitary drain into | dural sinuses |
| posterior lobe of pituitary is actually part of | the brain |
| nerve bundles that run through the infundibulum and connect the neurohypophysis and the hypothalamus | hypothalamic-hypophyseal tract |
| hypothalamic-hypophyseal tract arises from __ in spraoptic & paraventricular nuclei of hypothalamus | neurons |
| made primarily by paraventricular neurons of hypothalamic-hypophyseal tract | oxytocin |
| made primarily by supraoptic neurons of hypothalamic-hypophyseal tract | antidiuretic hormone (ADH) |
| when hypothalamic-hypophyseal tract neurons fire they release the stored hormones into a capillary bed in __ pituitary for distribution throughout the body | posterior |
| originates from a superior outpocketing of oral mucosa (Rathke's pouch) and is formed from epithelial tissue | anterior lobe of pituitary |
| after touching posterior lobe, anterior lobe of pituitary loses it connection with oral mucosa & adheres to | neurohypophysis |
| there is no __ __ connection between anterior lobe of pituitary & hypothalamus | direct neural |
| only connection between anterior lobe of pituitary & hypothalamus is | vascular |
| unusual arrangement of blood vessels in which a capillary bed feeds into veins, which in turn feed into another capillary bed | portal system |
| primary capillary plexus is located in | the infundibulum |
| located in the infundibulum, it communicates inferiorly via the small hypophyseal portal veins with a secondary capillary plexus | primary capillary plexus |
| primary & secondary capillary plexuses & intervening hypophyseal portal veins make up the | hypophyseal portal system |
| releasing & inhibiting hormones secreted by neurons in ventral hypothalamus circulate to __ __ via the hypophyseal portal system | anterior pituitary |
| hypophyseal portal system is where the regulation of hormone __ takes place for the anterior pituitary | secretion |
| all hypothalamic regulatory hormones are __ __ based | amino acid |
| hypothalamic regulatory hormones can be a(n) | single amine to peptides to proteins |
| controls activity of anterior pituitary | hypothalamus |
| all anterior pituitary hormones are | proteins |
| large molecule isolated from anterior pituitary; prohormone & source of andrenocorticotropic hormone, enkephalin & beta endorphin, & melanocyte-stimulating hormone (MSH) | pro-opiomelanocortin (POMC) |
| CNS neurotransmitter involved in control of appetite | melanocyte-stimulating hormone (MSH) |
| hormone that regulates the secretory action of another endocrine organ | tropic hormone |
| thyroid-stimulating hormone, andrenocorticotropic hormone, follicle-stimulating hormone, & luteinizing hormone are all | tropic |
| all anterior pituitary hormones except for __ hormone affect their target cells via cyclic AMP second-messenger system | growth |
| hormone that stimulates growth in general; produced in the anterior pituitary; also called somatotropin (STH) | growth hormone (GH) |
| GH is produced by cells called | somatotrophs |
| GH promotes growth and __ actions | metabolic |
| major target(s) of GH are | bones & skeletal muscles |
| stimulation of __ __, by GH, leads to long bone growth | epiphyseal plate |
| stimulation of skeletal muscles by GH promotes increased __ __ | muscle mass |
| GH is a(n) __ hormone | anabolic |
| GH promotes protein __ | synthesis |
| GH encourages use of __ for fuel, thus conserving glucose | fats |
| family of growth-promoting proteins produced by liver, skeletal muscles, bone, & other tissues; mediated growth promoting effects of GH | insulin-like growth factors (IGFs) |
| IGFs produced by __ act as hormones | liver |
| IGFs produced in tissues other than liver act as | paracrines |
| IGFs stimulate actions required for growth by uptake of nutrients from blood & their incorporation into proteins & DNA allowing growth by | cell division |
| IGFs stimulate actions required for growth through formation of __ & deposition of __ __ | collagen; bone matrix |
| acting directly GH mobilizes fat for depots for transport to cells, thus increasing levels of | fatty acids |
| acting directly GH __ rate of glucose uptake and metabolism | decreases |
| in the liver GH encourages glycogen breakdown & | release of glucose to blood |
| the elevation blood glucose levels that occurs when GH acts upon liver brings about the __ __ or anti-insulin effect of GH | glucose sparing |
| hormone from hypothalamus that stimulates GH release | growth hormone-releasing hormone (GHRH) |
| hormone from hypothalamus that inhibits GH release | growth hormone-inhibiting hormone (GHIH) |
| GHIH releases is triggered by __ of GH & IGFs | feedback |
| rising levels of GH feed back to also __ its own release | inhibit |
| GH has a daily cycle with the highest levels occurring during | evening sleep |
| GHIH __ release of thyroid-stimulating hormone | blocks |
| GHIH is produced in the gut where its release inhibits virtually all gastrointestinal & pancreatic __ | secretions |
| excessive growth of the body or any of its parts, especially as a result of oversecretion of the growth hormone by the pituitary gland | gigantism |
| chronic disease of adults marked by enlargement of the bones of the extremities, face, and jaw that is caused by overactivity of the pituitary gland secretion of GH | acromegaly |
| GH deficiency in children results in slowed long bone growth | pituitary dwarfism |
| tropic adenohypophyseal hormone that regulates secretion of thyroid hormones | thyroid-stimulating hormone (TSH) |
| thyroid-stimulating hormone (TSH) is also called | thyrotopin |
| release of thyroid-stimulating hormone (TSH) follows | hypothalmic-pituitary-target endocrine feedback loop |
| cells of anterior pituitary that release TSH | thyrotrophs |
| triggers thyrotrophs to release TSH | thyrotropin-releasing hormone (TRH) |
| rising blood levels of thyroid hormones act on pituitary & hypothalamus to | inhibit TSH secretion |
| anterior pituitary hormone that stimulates adrenal cortex to release corticosteroid hormones | adrenocorticotropic hormone (ACTH) |
| adrenocorticotropic hormone (ACTH) also called | corticotropin |
| ACTH release is elicited by hypothalamic | corticotropin-releasing hormone (CRH) |
| ACTH levels peak in | morning shortly before awakening |
| rising levels of glucocorticoids feed back and __ secretion of CRH & ACTH release | block |
| internal & external factors that alter normal ACTH rhythm by triggering CRH release include | fever, hypoglycemia, & stressors of all types |
| hormone produced by the anterior pituitary that stimulates ovarian follicle production in females and sperm production in males | follicle-stimulating hormone (FSH) |
| anterior pituitary hormone that aids maturation of cells in the ovary and triggers ovulation in females; in males, causes the interstitial cells of the testis to produce testosterone | luteinizing hormone (LH) |
| luteinizing hormone (LH) & follicle-stimulating hormone (FSH), produced by anterior pituitary, are referred to collectively as | gonadotropins |
| in both sexes FSH stimulates __ production | gamete |
| in females, LH works with FSH to cause an __ __ __ to mature | egg-containing ovarian follicle |
| in both sexes LH promotes production of __ hormones | gonadal |
| in females, LH independently triggers __ | ovulation |
| in females, LH independently promotes synthesis & release of __ hormones | ovarian |
| in males, LH stimulates __ __ of testes to produce testosterone | interstitial cells |
| gonadotropins are virtually __ from blood of prepuberty boys & girls | absent |
| during puberty to gondotrophs of anterior pituitary are activated and gonadotropin levels begin to rise, causing | gonads to mature |
| in both sexes, produced by hypothalamus, gondaotropin release by anterior pituitary is promoted by | gonadotropin-releasing hormone (GnRH) |
| produced in response to the gonadotropins, feed back to suppress FSH & LH | gonadal hormones |
| adenohypophyseal hormone that stimulates the breasts to produce milk; protein hormone structurally similar to GH | prolactin (PRL) |
| prolactin release is controlled primarily by inhibitory hormone prolactin-inhibiting hormone (PIH), known as | dopamine |
| prolactin-releasing factor | TRH |
| in females, prolactin levels rise & fall in rhythm with __ blood levels | estrogen |
| estrogen stimulates prolactin release | directly & indirectly |
| most frequent abnormality of anterior pituitary tumors | hyperprolactinemia |
| made largely of axons of hypothalamic neurons; stores antidiuretic hormone (ADH) and oxytocin | posterior pituitary |
| composed of 9 amino acids; differ in only 2 amino acids | ADH & oxytocin |
| influences body water balance | ADH |
| hormone synthesized in the hypothalamus and secreted by the posterior pituitary; stimulates contraction of the uterus during childbirth and the ejection of milk during nursing | oxytocin |
| oxytocin acts via __ second-messenger system to mobilize Ca2+ allowing stronger contractions | PIP-Ca2+ |
| childbirth & milk ejection result from | positive feedback mechanisms |
| urine production | diuresis |
| substance that inhibits or prevent urine formation | antidiuretic |
| hormone produced by the hypothalamus and released by the posterior pituitary; stimulates the kidneys to reabsorb more water, reducing urine volume | antidiuretic hormone (ADH) |
| ADH is also called | vasopressin |
| ADH prevents wide swings in __ balance | water |
| sensory end organ that responds to changes in osmotic pressure; continually monitors solute concentration of blood | osmoreceptor |
| ADH targets __ __ via cAMP | kidney tubules |
| pain, low blood pressure, & drugs such as nicotine, morphine, & barbiturates are all stimuli that trigger | ADH release |
| drinking alcoholic beverages __ ADH secretion | inhibits |
| diuretic drugs __ effects of ADH and cause water to be flushed from the body | antagonize |
| at high blood concentrations ADH causes __ of the visceral blood vessels | vasoconstriction |
| disease characterized by passage of a large quantity of dilute urine plus intense thirst and dehydration caused by inadequate release of antidiuretic hormone (ADH) | diabetes insipidus |
| pulmonary cancers are known to | secrete ADH |
| marked by retention of fluid, headache & disorientation due to brain edema, weight gain & decreased solute concentration in blood | syndrome of inappropriate ADH secretion (SIADH) |
| one of the largest of the body's endocrine glands; straddles the anterior trachea | thyroid gland |
| median tissue mass of thyroid gland | isthmus |
| hollow, spherical, colloid-containing structure of the thyroid gland | follicles |
| formed largely by cubiodal or squamous epithelial cells & produce glycoprotein thyrogolubulin | follicle cells |
| central cavity of thyroid follicle | lumen |
| lumen of thyroid follicle __ colloid | stores |
| amber-colored, sticky substance in the thyroid gland containing thyroglobulin protein with attached iodine atoms | colloid |
| derived from iodinated thyroglobulin | thyroid hormone |
| population of cells in thyroid gland that produce calcitonin; lie in follicular epithelium but protrude into soft connective tissue that separates & surrounds thyroid follicles | parafollicular cells |
| major hormone secreted by thyroid follicles; stimulates enzymes concerned with glucose oxidation | thyroid hormone (TH) |
| thyroid hormone (TH) is often referred to as the body's | major metabolic hormone |
| iodine-containing hormone secreted by the thyroid gland; accelerates cellular metabolic rate in most body tissues; major hormone secreted by thyroid follicles | thyroxine (T4) |
| thyroid hormone; secretion and function similar to those of thyroxine (T_4) | triiodothyronine (T3) |
| most T3 is formed at the target tissue by | conversion of T4 to T3 |
| TH enters a target cell and | initiates transcription of mRNA for protein synthesis |
| by turning on transcription of genes concerned with glucose oxidation, TH | has calorigenic effect |
| increases basal metabolic rate & body heat production | calorigenic effect |
| TH provokes increase in number of __ receptors in blood vessels, playing important role in maintaining blood pressure | adrenergic |
| important in regulating tissue growth & development, as well as critical for normal skeletal & nervous system development/maturation, & reproductive capabilities | TH |
| thyroid gland has ability to store its hormone extracellulary & stored amount remains constant & sufficient to provide levels of hormone release for | two to three months |
| when TSH from anterior pituitary binds to receptors on thyroid follicle cells, first response is to | secrete stored thyroid hormone |
| when TSH from anterior pituitary binds to receptors on thyroid follicle cells, second response is to | begin synthesizing more colloid to restock thyroid follicle lumen |
| TSH levels are __ during the day | lower |
| TSH levels __ just before sleep | peak |
| TSH levels remain __ during the night | high |
| when thyroglobulin is synthesized and discharged into follicle lumen | step 1 synthesis of TH by follicle cells |
| iodide is trapped by active transport by follicle cell, then moves into lumen by facilitated diffusion | step 2 synthesis of TH by follicle cells |
| iodide is oxidized to iodine | step 3 synthesis of TH by follicle cells |
| iodine is attached to tyrosine at junction of follicle cell apex & colloid, & is mediated by peroxidase enzymes | step 4 synthesis of TH by follicle cells |
| attachment of 1 iodine to a tyrosine produces | monoiodotyrosine (MIT or T1) |
| attachment of 2 iodine to a tyrosine produces | diiodotyrosine (DIT or T2) |
| iodinated tyrosines are linked together to form T3 & T4; enzymes in colloid link MIT & DIT together; hormones are still part of thyroglobulin colloid | step 5 synthesis of TH by follicle cells |
| 2 DITs result in | T4 |
| coupling of MIT & DIT produces | T3 |
| thyroglobulin colloid is endocystosed; follicle cells must reclaim iodinated thyroglobulin by endocytosis & combine vesicles with lysosomes | step 6 synthesis of TH by follicle cells |
| lysosomal enzymes cleave T4 & T3 from thyroglobulin & hormones diffuse from follicle cell into bloodstream | step 7 synthesis of TH by follicle cells |
| some T4 cane be converted to T3 __ secretion | before |
| most T3 is generated in | peripheral tissues |
| most T3 & T4 released immediately binds to transport proteins, most importantly | thyroxine-binding globulins (TBGs) |
| thyroxine-binding globulins (TBGs) are produced by | the liver |
| T3 that binds to target tissue receptors does so | much more avidly & is about 10x more active |
| most peripheral tissues have enzymes needed to convert T4 to T3 by | removing one iodine |
| regulation of blood levels of TH is on a(n) | negative feedback loop |
| falling TH blood levels trigger __ of TSH | release |
| rising levels of TH feed back to __ hypothalamic-anterior pituitary axis, temporarily shutting off stimulus for TH release | inhibit |
| condition that increase body energy requirements, such pregnancy & exposure of infants to cold, stimulate hypothalamus to secrete __ __ which triggers TSH release allowing it to overcome negative feedback controls | thyrotropin-releasing horomone (TRH) |
| GHIH, dopamine, & rising levels of glucocorticoids are factors that | inhibit TSH release |
| excessively high blood iodine concentrations inhibit | TH release |
| condition resulting from underactive thyroid gland in adults | myxedema |
| if myxedema results from lack of iodine, enlargement & protrusion of thyroid gland | endemic/colloidal goiter |
| severe hypothyroidism in infants | cretinism |
| disorder resulting from hyperactive thyroid gland | Grave's disease |
| protrusion of eyeballs, if tissue behind eyes becomes edematous & then fibrous; common in Grave's disease | exophthalmos |
| polypeptide hormone released by the thyroid; lowers blood calcium levels only when present at high (therapeutic) levels | calcitonin |
| calcitonin is produced by | parafollicular / C cells |
| effect of calcitonin is is to __ blood Ca2+ | lower |
| calcitonin has an antagonizing effect on __ hormone | parathyroid |
| targets of calcitonin include | skeleton & bony matrix |
| targeting the skeleton, calcitonin inhibits __ activity, inhibiting bone reabsorption & release of Ca2+ from bony matrix | osteoclast |
| targeting the bony matrix, calcitonin __ Ca2+ uptake & incorporation into bone matrix | stimulates |
| calcitonin has a __ effect | bone-sparing |
| excessive blood levels of Ca2+ (approx. 20% above normal) act as a __ stimulus for calcitonin release | humoral |
| declining blood Ca2+ levels inhibit C cell __ Activity | secretory |
| calcitonin is given therapeutically to patient's with | Paget's disease |
| small endocrine glands located on the posterior aspect of the thyroid gland | parathyroid glands |
| parathyroid glands are arranged in thick branching cords containing scattered __ cells and large numbers of smaller __ cells | oxyphil; chief |
| most abundant parenchymal cells of the parathyroid, being polygonal epithelial cells rich in glycogen, having granular cytoplasm and vesicular nuclei, and arranged in plates or cords | chief cells |
| acidophilic cells found in the parathyroid glands | oxyphil cells |
| protein hormone released by parathyroid glands; single most important hormone regulating blood calcium level | parathyroid hormone (PTH)/parathormone |
| Ca2+ homeostasis is essential for so many functions, including | transmission of nerve impulses, muscle contraction, & blood clotting |
| PTH release is triggered by __ blood Ca2+ levels | falling |
| PTH release is inhibited by __ blood Ca2+ levels | rising |
| PTH increases Ca2+ levels in blood by stimulating targets organs of | skeleton, kidneys, & intestine |
| skeleton contains considerable amount of __ __ in its matrix, making it an apt target organ of PTH | calcium salts |
| bone-reabsorbing cells | osteoclast |
| PTH release stimulates osteoclast to digest some of the bony matrix and release ionic calcium & phosphates to the blood | step 1 PTH |
| enhances reabsorption of Ca2+, as well as excretion of phosphate (PO43-) by kidneys | step 2 PTH |
| promotes activation of vitamin D3 thereby increasing absorption of Ca2+ by intestinal mucosal cells | step 3 PTH |
| required for absorption of Ca2+ from food | vitamin D |
| vitamin D ingested or produced by skin is a(n) | inactive form |
| for vitamin D to exert its physiological effects it must be converted by kidneys to its active vitamin D3 form of | calcitriol |
| group of active metabolites of cholecalciferol (vitamin D3);increases intestinal absorption of calcium & phosphate, enhances bone resorption, & prevents rickets | dihydroxycholecalciferol/calcitriol |
| rare & usually results from tumor; calcium is leached from bones causing bones to soften & deform as their mineral salts are replaced by fibrous connective tissue | hyperparathyroidism |
| bones have moth-eaten appearance on x-rays & tend to fracture spontaneously | osteitis fibrosa cystica |
| abnormally elevated blood Ca2+ levels | hypercalcemia |
| hypercalcemia causes __ of nervous system and formation of __ stones | depression; kidney |
| calcium deposits that form is soft tissues throughout body & severely impair vital organ functioning | metastatic calcification |
| PTH deficiency; often follows parathyroid gland trauma or removal during thyroid surgery | hypoparathyroidism |
| extended deficiency of dietary magnesium, required for PTH secretion) can cause | functional hypoparathyroidism |
| low blood Ca2+ levels | hypocalcemia |
| hypocalcemia resulting from functional hypoparathyroidism __ excitability of neurons & accounts for classical symptoms of tetany | increases |
| loss of sensation, muscle twitches, & convulsions | tetany |
| untreated symptoms of functional hypoparathyroidism progress to | respiratory paralysis & death |
| hormone-producing pyramid-shaped organs located superior to kidneys; each consists of medulla & cortex areas | adrenal glands |
| adrenal glands are enclosed in | fibrous capsule & cushion of fat |
| adrenal glands are often referred to as | suprarenal glands |
| each adrenal glands is structurally & functionally | two endocrine glands |
| inner portion; more like a knot of nervous tissue; part of sympathetic nervous system | adrenal medulla |
| outer portion; encapsulating medulla & forming bulk of gland; glandular tissue derived from embryonic mesoderm | adrenal cortex |
| each region of adrenal gland produces | its own hormones |
| all adrenal hormones help up | cope with stressful situations |
| over two dozen steroid hormones synthesized by adrenal cortex are called | corticosteroids |
| multistep steroid synthesis pathway, of adrenal cortex, starts with | cholesterol |
| steroid hormones are not __ in cells | stored |
| the rate of steroid hormone release in response to stimulation depends on their | rate of synthesis |
| large, lipid-laden cortical cells of adrenal cortex are arranged in | 3 layers/zones |
| cell clusters forming superficial layer; produce mineralocorticoids | zona glomerulosa |
| steroid hormone of adrenal cortex that regulates Na^+ & K^+ metabolism & fluid balance | mineralocorticoids |
| cells forming middle layer; arranged in more/less linear cords; produce glucocorticoids | zona fasciculata |
| steroid hormones that affect glycogenesis in the liver; anti-inflammatory, are active in protection against stress, and affect carbohydrate and protein metabolism | glucocorticoids |
| innermost cells abutting adrenal medulla in netlike arrangement; mainly produce small amounts of gonadocorticoids | zona reticularis |
| adrenal sex hormones | gonadocorticoids |
| 2 innermost layers of adrenal cortex __ __ of glucocorticoids & gonadocorticoids, although each layer predominately produces one type | share production |
| single most abundant cation in extracellular fluid is | Na+ |
| amount of Na+ in body largely determines __ of extracellular fluid | volume |
| where Na+ goes __ follows | water |
| lead to changes in blood volume & blood pressure | changes in Na+ blood concentration |
| coupled to Na+ is regulation of other ions, including | K+, H+, HCO3 (bicarbonate), & Cl- (chloride) |
| sets the resting membrane potential of cells & determine how easily action potentials are generated in nerve & muscle | extracellular contractions of K+ |
| Na+ & K+ __ are crucial to overall body homeostasis | regulation |
| hormone produced by the adrenal cortex that regulates Na+ reabsorption and K+ secretion by the kidneys | aldosterone |
| aldosterone is the most __ mineralocorticoid | potent |
| aldosterone accounts for __ __ 95% of the mineralocorticoids produced | more than |
| aldosterone __ excretion of Na+ from body | reduces |
| primary target of aldosterone is __ parts of kidney tubules, where it stimulate Na+ reabsorption & water retention accompanied by K+ elimination | distal |
| in some instances aldosterone's effect on distal kidney tubules can alter __ balance of blood by H+ excretion | acid-base |
| aldosterone __ Na+ reabsorption from perspiration, saliva, & gastric juice | enhances |
| aldosterone's regulatory effects are __ lasting approx. 20 minutes, allowing plasma electrolyte balance to be precisely controlled | brief |
| involves synthesis & activation of proteins required for Na+ transport, such as Na+-K+ ATPase, pump that exchanges Na+ for K+ | mechanism of aldosterone activity |
| aldosterone is also secreted by __ organs | cardiovascular |
| in cardiovascular organs aldosterone is a(n) | paracrine |
| aldosterone secretion is __ by decreasing blood volume & pressure, as well as rising levels of K+ | stimulated |
| renin-angiotensin, plasma concentrations of K+, ACTH, & atrial natriuretic peptide (ANP) | mechanisms that regulate aldosterone secretion |
| hormone released by the kidneys that is involved with raising blood pressure | renin |
| influences both blood volume & pressure by regulating release of aldosterone and therefore Na+ & water reabsorption by kidneys | renin-angiotensin mechanism |
| in renin-angiotensin mechanism, specialized cells of __ __ in kidneys become excited when blood pressure/volume declines, and thus release renin | juxtaglomerular apparatus |
| in renin-angiotensin mechanism, when renin is released it cleaves off part of plasma protein angiotensinogen, which triggers | enzymatic cascade leading to formation of angiotensin II |
| potent vasoconstrictor activated by renin; also triggers release of aldosterone by glomerulosa cells | angiotensin II |
| all of effects of renin-angiotensin mechanism are ultimately involved in | raising blood pressure |
| fluctuating blood levels of K+ directly influence zona glomerulosa cells in adrenal cortex; increased K+ stimulates aldosterone release, whereas decreased K+ inhibits it | plasma concentration of K+to regulate aldosterone secretion mechanism |
| under severe stress, hypothalamus secretes more corticotropin-releasing hormone (CRH), 7 resulting rise in ACTH blood levels steps up rate of aldosterone secretion to small extent; resulting in increased blood volume/pressure | ACTH mechanism to regulate aldosterone secretion |
| hormone secreted by heart when blood pressure rises; fine-tunes blood pressure & sodium-water balance of body | atrial natriuretic peptide (ANP) |
| one of major effects of atrial natriuretic peptide (ANP) is to | inhibit renin-angiotensin mechanism |
| ANP blocks renin & aldosterone secretion & inhibits other __ mechanisms that enhance water & Na+ reabsorption | angiotensin-induced |
| decrease blood pressure by allowing Na+ (and water_ to flow out of body in urine | ANP mechanism's overall influence |
| producing salty urine | natriuretic |
| hypersecretion of aldosterone; typically results from adrenal tumors | aldosteronism |
| if K+ loss is __ neurons become nonresponsive & muscle weakness (eventually paralysis) occurs | extreme |
| hyposecretory disease of adrenal cortex, generally involving a deficient output of both mineralocorticoids & glucocorticoids | Addison's disease |
| glucocorticoids are adrenal cortex hormones that | increase blood glucose levels and aid the body in resisting long-term stressors |
| under normal circumstances glucocorticoids help body to adapt to intermittent food intake by keeping __ __ levels fairly constant, and maintain blood pressure by increasing action of __ | blood glucose; vasoconstrictors |
| severe stress due to hemorrhage, infection, or physical/emotional trauma evokes a dramatically __ output of glucocorticoids, which help body negotiate crisis | higher |
| cortisol, cortisone, corticosterone | glucocorticoid hormones |
| glucocorticoid produced by the adrenal cortex; release is promoted by ACTH; rising levels feed back to act on both hypothalamus & anterior pituitary | cortisol (hydrocortisone) |
| basic mechanism of glucocorticoid action on target cells is to | modify gene activity |
| glucocorticoid secretion is regulated by | negative feedback |
| driven by patterns of eating & activity, occur in a definite pattern throughout day & night | cortisol secretory bursts |
| cortisol blood levels peak __ __ we arise in morning | shortly before |
| __ __ of cortisol occur in evening just before and shortly after we fall asleep | lowest levels |
| __ __ __ can be interrupted by acute stress of any variety as higher CNS center override the usually inhibitory effects of elevated cortisol level & trigger CRH release | normal cortisol rhythm |
| under __ __ the resulting increase in ACTH blood levels causes an outpouring of cortisol from adrenal cortex | acute stress |
| stress results in __ __ in blood levels of glucose, fatty acids, and amino acids | dramatic rise |
| cortisol's __ __ effects is to provoke gluconeogenesis | prime metabolic |
| formation of glucose, especially by the liver, from noncarbohydrate sources, such as amino acids | gluconeogenesis |
| in order to save glucose for the __, cortisol mobilizes fatty acids from adipose tissue & encourages their increased use for energy | brain |
| under cortisol's influence, __ __ are broken down to provide building blocks for repair or for making enzymes to be used in metabolic processes | stored proteins |
| cortisol enhances the __ nervous system's vasoconstrictive effects, and the rise in blood pressure & circulatory efficiency that results helps ensure that these nutrients are quickly distributed to cells | sympathetic |
| cortisol __ is associated with significant inflammatory & anti-immune effects | excess |
| depress cartilage /bone formation; inhibit inflammation by decreasing release of inflammatory chemicals; depress immune system; promote changes in cardiovascular, neural & GI function | excessive levels of glucocorticoids |
| rheumatoid arthritis & allergic reactions use __ __ to control symptoms of chronic inflammatory disorders | glucocorticoid drugs |
| pathology of glucocorticoid excess; may be caused by ACTH-releasing pituitary tumor, ACTH-releasing malignancy of lungs, pancreas, or kidneys, or tumor of adrenal cortex | Cushing's disease |
| Cushing's disease is most often a result of clinical administration of __ __ of glucocorticoid drugs | pharmacological doses |
| characterized by persistent elevated blood glucose levels, dramatic losses in muscle/bone protein, & water/salt retention leading to hypertension & edema | Cushing's syndrome |
| persistent elevated blood glucose levels brought on by pharmacological doses of glucocorticoids | steroid diabetes |
| include swollen "moon" face, redistribution of fat to the abdomen & posterior neck, tendency to bruise, & poor wound healing | cushingoid signs |
| major hyposecretory disorder of adrenal cortex, usually involves deficits in both glucocorticoids & mineralcorticoids; weight loss, plasma glucose & sodium levels drop, & potassium levels rise | Addison's disease |
| sex hormones, primarily androgens, secreted by the adrenal cortex | gonadocorticoids |
| hormone such as testosterone that controls male secondary sex characteristics | androgen |
| androstenedione & dehydroepiandrosterone (DHEA) are converted to __ in tissue cells in males | testosterone |
| androstenedione & dehydroepiandrosterone (DHEA) are converted to __ in tissue cells in females | estrogens |
| hypersecretion of gonadocorticoids causes | adrenogenital syndrome |
| spherical cell that stains readily with chromium salts, especially a cell of the adrenal medulla | chromaffin cells |
| chromaffin cells are modified ganglionic __ __ that synthesize catecholamines | sympathetic neurons |
| chief hormone produced by the adrenal medulla; also called adrenaline | epinephrine |
| catecholamine neurotransmitter and adrenal medullary hormone, associated with sympathetic nervous system activation | norepinephrine (NE) |
| adrenal medulla synthesize catecholamines via __ __ from tyrosine to dopamine to NE to epinephrine | molecular sequence |
| blood glucose levels rise, blood vessels constrict & heart beats faster, blood is diverted from nonessential organs to heart & skeletal muscles & preganglionic sympathetic nerve endings weaving through adrenal medulla signal for catecholamine release | when sympathetic nervous system is mobilized, in flight-or-flight |
| release of catecholamines from adrenal medulla reinforce or prolong | fight-or-flight response |
| more potent catecholamine stimulator of metabolic activities, bronchial dilation, & increased blood flow to skeletal muscles & heart | epinephrine |
| catecholamine that has greater influence on peripheral vasoconstriction & blood pressure | norepinephrine |
| epinephrine is used clinically as heart stimulant & to dilate bronchioles during | acute asthmatic attack |
| catecholamines cause relatively __ responses to stressors | brief |
| deficiency of hormones of adrenal medulla is not a problem because these hormones merely __ activities set into motion by sympathetic nervous system | intensify |
| adrenal catecholamines __ __ essential for life | are not |
| produces symptoms of uncontrolled sympathetic nervous system activity | hypersecretion of catecholamines |
| symptoms include hyperglycemia, increased metabolic rate, rapid heartbeat & palpitations, hypertension, intense nervousness & sweating; tumor of chromaffin cells of adrenal medulla | pheochromocytoma |
| hormone-secreting part of diencephalon of brain thought to be involved in setting biological clock & influencing reproductive function | pineal gland |
| hormone secreted by pineal gland; secretion peaks at night and helps set sleep-wake cycles; also a powerful antioxidant | melatonin |
| pineal gland indirectly receives input from __ pathways concerning the intensity & duration of daylight | visual |
| area referred to as our biological clock; richly supplied with melatonin receptors | suprachiasmatic nucleus |
| gland located behind stomach, between spleen & duodenum; produces both endocrine & exocrine secretions | pancreas |
| zymogen-secreting cells of the pancreatic; produce enzyme-rich juice that is carried by ducts to small intestine during digestion | acinar cells |
| tiny cell clusters (scattered among acinar cells)that produce pancreatic hormones | pancreatic islets |
| pancreatic islets are also know as | islets of Langerhans |
| glucagon-synthesizing cells of pancreas | alpha cells |
| insulin-producing cells of pancreas | beta cells |
| act as tiny fuel sensors, secreting glucagon & insulin appropriately during fasting & fed states | alpha & beta cells |
| insulin is a(n) __ hormone | hypoglycemic |
| glucagon is a(n) __ hormone | hypoglycemic |
| some __ __ cells also produce peptides, such as somatostatin, pancreatic polypeptide (PP), etc. | pancreatic islet |
| hormone formed by alpha cells of pancreatic islets; raises the glucose level of blood; 29-amino-acid polypeptide | glucagon |
| one molecule of glucagon can release 100 million molecules of __ into the blood | glucose |
| breakdown of glycogen to glucose | glycogenolysis |
| glycogenolysis, gluconeogenesis, release of glucose to blood by liver cells, causing blood glucose levels to rise | major targets of glucagon |
| fall in amino acid concentration in blood as liver cells sequester glucagon molecules to make new glucose molecules | secondary effect of glucagon |
| humoral stimuli, falling glucose levels, prompt __ cells to secrete glucagon | alpha |
| sympathetic nervous system stimulation & rising amino acid levels are also __ for glucagon release | stimulatory |
| glucagon release is __ by rising blood glucose levels, insulin, & somatostatin | suppressed |
| hormone that enhances carrier-mediated diffusion of glucose into tissue cells, thus lowering blood glucose levels; small protein consisting of 2 amino acid chains linked by disulfide bonds | insulin |
| insulin is synthesized as part of a larger polypeptide chain called | proinsulin |
| main effect of insulin is to __ blood glucose levels, but it also influences protein & fat metabolism | lower |
| middle portion of proinsulin polypeptide chain is excised by enzymes releasing __ insulin | functional |
| functional insulin "clipping" takes places in secretory vesicles just before insulin is released | from the beta cells |
| insulin's effects are most obvious when we have | just eaten |
| main effect of insulin is to | lower blood sugar |
| insulin also influences | protein & fat metabolism |
| circulating insulin lowers blood glucose levels by enhancing membrane __ of glucose into body cells, especially muscle & fat | transport |
| circulating insulin lowers blood glucose levels by inhibiting __ of glycogen to glucose | breakdown |
| circulating insulin lowers blood glucose levels by __ conversion of amino acids or fats to glucose | inhibiting |
| insulin does no accelerate glucose entry into liver, kidney, & brain tissues because | they have easy access to blood glucose regardless of insulin levels |
| insulin roles in the __ participate in neuronal development, feeding behavior, & learning/memory | brain |
| inhibiting effects of insulin counter any metabolic activity that would increase __ __ of glucose | plasma levels |
| at cellular level insulin activates its receptor __ __ enzyme which phosphorylates specific proteins beginning the cascade that leads to increased glucose uptake & insulin's other effects | tyrosine kinase |
| after glucose enters target cell, insulin binding triggers enzymatic activities that catalyze __ of glucose for ATP production | oxidation |
| after glucose enters target cell, insulin binding triggers enzymatic activities that join glucose molecules together to | form glycogen |
| after glucose enters target cell, insulin binding triggers enzymatic activities that convert glucose to | fat, particularly in adipose tissue |
| as a rule, energy need are met first, followed by __ __ | glycogen formation |
| if excess glucose is available, after energy needs have been met, it is then | converted to fat |
| insulin stimulates amino acid uptake & protein synthesis in | muscle tissue |
| pancreatic beta cells are stimulated to secrete insulin chiefly by | elevated blood glucose levels |
| pancreatic beta cells are stimulated to secrete insulin by rising __ __ of amino & fatty acids | plasma levels |
| pancreatic beta cells are stimulated to secrete insulin by release of acetylcholine by __ nerve fibers | parasympathetic |
| as body cells take up glucose & other nutrients, and plasma levels of these substances drop, insulin secretion | is suppressed |
| glucagon, epinephrine, growth hormone, thyroxine, & glucocorticoids are all | hyperglycemia hormones |
| any hyperglycemia hormone called into action as blood glucose levels drop __ __ insulin release by promoting glucose entry into bloodstream | indirectly stimulates |
| somatostatin & sympathetic nervous system activation __ insulin release | depress |
| insulin is the major __ __ that counterbalances the many hypoglycemic hormones | hypoglycemic factor |
| disease caused by deficient insulin release or by insulin resistance, leading to inability of the body cells to use carbohydrates | diabetes mellitus (DM) |
| excess of glucose lost from body in urine | glycosuria |
| fatty acid metabolites; strong organic acids | ketones |
| sugars cannot be used as cellular fuel, more fats are mobilized resulting in high fatty acids levels in blood | lipidemia |
| when ketones accumulate in blood, the blood pH drops and ketones begin to spill into the urine | ketoacidosis |
| ketones begin to spill into the urine | ketonuria |
| polyuria, polydipsia, & polyphagia are the three __ __ of diabetes mellitus | cardinal signs |
| excessive glucose in kidney filtrate act as __ __ resulting in polyuria | osmotic diuretic |
| excessive urine output | polyuria |
| excessive thirst | polydipsia |
| excessive hunger & food consumption | polyphagia |
| excessive insulin secretion | hyperinsulinism |
| hyperinsulinism __ __ hypoglycemia | results in |
| hyperinsulinism can result from __ __ tumor | islet cell |
| hyperinsulinism can result from an __ of insulin | overdose |
| male & female gonads produce steroid sex hormones __ to those produced by adrenal cortical cells | identical |
| ovaries produce important hormones of | estrogen & progesterone |
| temporary endocrine organ; secretes several steroid & protein hormones that influence course of pregnancy | placenta |
| include estrogens & progesterone, as well as human chorionic gonadotropin (hCG) | placental hormones |
| prompts kidneys to increase their production of salty urine & inhibits aldosterone release by adrenal cortex; thereby decreasing amount of sodium in extracellular fluid, reducing blood volume & pressure | ANP |
| hormone secreting cells sprinkled in mucosa of GI tract; release several peptide hormones that help regular wide variety of digestive functions | enteroendocrine cells |
| enteroendocrine cells release amines, like serotonin acting as paracrines, diffusing to & influencing nearby target cells without first | entering bloodstream |
| enteroendocrine cells are sometimes referred to as __ because they are similar in certain ways to neurons & many of their hormones & paracrines are chemically identical to neurotransmitters | paraneurons |
| hormone that stimulates production of red blood cells; protein hormones that signals bone marrow to increase RBC production | erythropoietin (EPO) |
| erythropoietin is secreted by interstitial cells in | kidneys |
| hormones function of kidneys is secretion of | erythropoietin & renin |
| inactive form of vitamin D, when modified cholesterol molecules in epidermal cells are exposed to UV radiation | cholecalciferol |
| cholecalciferol is hormone secreted from | skin |
| cholecalciferol is modified in the __ and becomes fully activated in the __ | liver; kidneys |
| calcitrol is __ __ of carrier system that intestinal cells use to absorb Ca2+ from ingested food | essential regulator |
| hormone released by fat cells that signals satiety; serves to tell body how much stored energy is available | leptin |
| leptin binds to CNS neurons concerned with __ __ | appetite control |
| hormones released by adipose cells that affect sensitivity of cells to insulin | resistin & adiponectin |
| insulin antagonist secreted by adipose tissue | resistin |
| enhances sensitivity to insulin & is secreted by adipose tissue | adiponectin |
| hormone secreted by osteoblasts that prods pancreatic beta cells to divide & secrete more insulin; restricts fat storage by adipocytes & triggers release of adiponectin | osteocalcin |
| is that glucose handling is improved & body fat is reduced | result of osteocalcin |
| osteocalcin levels are __ in type 2 diabetes | low |
| lymphoid organ and endocrine gland active in immune response; site of maturation of T lymphocytes | thymus |
| peptide hormones secreted by thymus; thought to be involved in normal development of T lymphocytes & immune response | thymulin, thymopoietins, & thymosins |
| thymulin, thymopoietins, & thymosins are called hormones but they | mainly act as paracrines |
| hormone-producing glands arise from | all three embryonic germ layers |
| endocrine glands derived from __ produce steroid hormones | mesoderm |
| endocrinology involves the study of | endocrine organs and hormones |
| steroids are | synthesized from cholesterol |
| any given hormone will influence the activity of | its target cell |
| PIP2-calcium signaling mechanism is mechanisms of hormone action in which | intracellular calcium ions act as a final mediator |
| down-regulation involves | loss of receptors & prevents target cells from overreacting to persistently high hormone levels |
| when one hormone opposes the action of another hormone, the interaction is called | antagonism |
| within a negative feedback system the target organ effects | inhibit further hormone release |
| anterior pituitary has traditionally been called the "master endocrine gland" because | many of the numerous hormones it produces regulate the activity of other endocrine glands |
| in recent years, anterior pituitary has been dethroned by the __, which is now known to control the activity of the anterior pituitary | hypothalamus |
| growth hormone stimulates | most body cells to increase in size and divide |
| pituitary dwarfism is homeostatic imbalance resulting from | hyposecretion of growth hormone |
| follicle-stimulating hormone | stimulates gamete (sperm or egg) production |
| as blood levels of __ __, the expulsive contractions of labor gain momentum and finally end in birth | oxytocin rise |
| because TH provokes an increase in number of __ __ in blood vessels, it plays an important role in maintaining blood pressure | adrenergic receptors |
| chief cells are | found within the parathyroid gland that secrete parathyroid hormone |
| if left untreated hypoparathyroidism can | lead to paralysis/death |
| Addison's disease is homeostatic imbalance that usually results from | deficits in both glucocorticoids & mineralocorticoids |
| adenohypophysis secretes | TSH |
| neurohypophysis secretes | ADH |
| thyroid gland secretes | calcitonin |
| adrenal gland secretes | aldosterone |
| pineal gland secretes | melatonin |
| FSH | stimulates development of the follicle in the ovaries |
| GH | mobilizes fats, spares glucose, and promotes the protein synthesis necessary for growth |
| ACTH | stimulate adrenal cortex |
| TSH | stimulate thyroid gland |
| ADH | stimulates kidney tubules to reabsorb water from urine |
| condition that would be balanced by insulin | high levels of blood sugar |
| condition that would be balanced by ADH | loss of body fluids |
| condition that would be balanced by aldosterone | loss of Na+ from extracellular fluids |
| condition that would be balanced by thyroxine | decrease in body metabolism |
| condition that would be balanced by parathyroid hormone | decrease in blood Ca+ levels |
| function of thyroid-stimulating hormone | stimulates production of thyroxine |
| function of growth hormone | causes cells to undergo mitosis & increase in size |
| function of oxytocin | increases contraction of uterine smooth muscles |
| function of adrenocorticotropic hormone | causes adrenal cortex to produce hormones |
| function of follicle-stimulating hormone | affects functions of ovaries & testes |
| site of release & function of TSH | anterior pituitary; causes thyroid gland to synthesize thyroxine |
| site of release & function of FSH | anterior pituitary; causes ovarian follicles to grow & produce estrogen & spermatogenesis in testes |
| site of release & function of LH | anterior pituitary; causes ovulation & interstitial cells to produce testosterone in testes |
| site of release & function of oxytocin | posterior pituitary; causes uterine contractions |
| site of release & function of ADH | posterior pituitary; causes kidneys to conserve water |
| function of prolactin | stimulates mild production |
| function of oxytocin | stimulates milk ejection from mammary glands |
| function of thyroxine | increase metabolic rate |
| function of calcitonin | lowers blood Ca2+ levels |
| function of parathyroid hormone | raises blood Ca2+ levels |
| gland/organ that produces calcitonin | thyroid gland |
| gland/organ that produces parathyroid hormone | parathyroid glands |
| gland/organ that produces adrenocorticotropic hormones | pituitary gland |
| gland/organ that produces glucocorticoids | adrenal cortex |
| gland/organ that produces epinephrine | adrenal medulla |
| pineal gland produces | melatonin |
| testes produce | testosterone |
| thymus produces | thymosin |
| heart produces | atrial natriuretic peptide |
| placenta produces | human chorionic gonadotropin (HCG) |
| function of melatonin | associated with drowsiness at night |
| function of testosterone | associated with sexual maturity in males; needed for normal sperm production |
| function of thymosin | essential for normal immune response |
| function of atrial natriuretic peptide | reduces blood volume, blood pressure, and blood sodium concentration by signaling the kidneys |
| function of HCG | helps to sustain pregnancy |
| hormone that adipose tissue produces | leptin |
| hormone that skin produces | cholecalciferol |
| hormone that kidney produces | erythropoietin |
| hormone that duodenum of small intestine produces | cholecystokinin |
| hormone that stomach produces | gastrin |
| function of leptin | binds to CNS neurons concerned with appetite control |
| function of cholecalciferol | activated by the kidneys to Vitamin D; stimulates active absorption of Ca2+ by intestinal cells |
| function of erythropoietin | stimulates the production of red blood cells |
| function of cholecystokinin | stimulates release of bile |
| function of gastrin | stimulates stomach to released hydrochloric acid |
| organ that produces glucagon | pancreas |
| organ that produces TSH | anterior pituitary (adenohypophysis) |
| organ that produces thyroxine | thyroid gland |
| organ that produces renin | kidneys |
| organ that produces ADH | posterior pituitary (neurohypophysis) |
| function of glucagon | increases blood sugar level by stimulating liver |
| function of TSH | stimulates the thyroid gland to produce thyroxine |
| function of thyroxine | increases the metabolic rate |
| function of erythropoietin | increases red blood cell production |
| function of ADH | increases water reabsorption in kidney tubules |
| category of hormone of FSH & LH | gonadotropins |
| category of hormone of cortisol | glucocorticoids |
| category of hormone of androgens | gonadocorticoids |
| category of hormone of aldosterone | mineralocorticoids |
| function of gonadotropins | regulate functions of gonads in both sexes |
| function of glucocorticoids | increase blood levels of glucose, fatty acids, and amino acids during stress |
| function of androgens | produce masculinizing effects when produced in large quantities |
| function of mineralocorticoids | regulate Na+ reabsorption by the kidneys and thereby regulates other electrolyte levels |
| hormone produced by posterior pituitary | antidiuretic hormone |
| hormone produced by anterior pituitary | growth hormone |
| hormone produced by pancreas | insulin |
| hormone produced by adrenal cortex | aldosterone |
| hormone produced by adrenal medulla | epinephrine |
| function of antidiuretic hormone | causes kidneys to conserve water |
| function of growth hormone | stimulates embryonic cells (stem cells) to undergo mitosis |
| function of insulin | facilitates glucose transport into cells |
| function of aldosterone | increases Na+ reabsorption in the kidneys |
| function of epinephrine | increases cell reactions during sympathetic response |
| hormone that would help to restore the balance for homeostatic imbalance of lowered levels of Ca2+ in the blood | parathyroid hormone |
| hormone that would help to restore the balance for homeostatic imbalance of too much Ca2+ in blood | calcitonin |
| hormone that would help to restore the balance for homeostatic imbalance of elevated levels of blood sugar | insulin |
| hormone that would help to restore the balance for homeostatic imbalance of decreased levels of blood sugar | glucagon |
| hormone that would help to restore the balance for homeostatic imbalance of excessive levels of Na+ in extracellular fluids | aldosterone |
| gland that would produce the hormone needed to restore homeostasis for end of 9 month pregnancy | posterior pituitary |
| gland that would produce the hormone needed to restore homeostasis for loss of Na+ from profuse sweating | adrenal cortex |
| gland that would produce the hormone needed to restore homeostasis for high blood sugar due to eating too many sweets | pancreas |
| gland that would produce the hormone needed to restore homeostasis for drop in blood levels of Ca2+ due to extreme inactivity | parathyroid |
| gland that would produce the hormone needed to restore homeostasis for delayed/stunted growth | anterior pituitary |
| homeostatic imbalance of gigantism would be due to the hormone deficiency/overproduction of | overproduction of GH |
| homeostatic imbalance of diabetes mellitus would be due to the hormone deficiency/overproduction of | insulin deficiency |
| homeostatic imbalance of sympathetic nervous system overactivity would be due to the hormone deficiency/overproduction of | oversecretion of catecholamines |
| homeostatic imbalance of Grave's disease would be due to the hormone deficiency/overproduction of | hypersecretion of thyroid hormone |
| homeostatic imbalance of diabetes insipidus would be due to the hormone deficiency/overproduction of | hyposecretion of ADH |
| principle hormone produced by zona reticularis | androgens |
| principle hormone produced by zona glomerulosa | mineralocorticoids |
| principle hormone produced by zona fasciculate | glucocorticoids |
| principle hormone produced by beta cells | insulin |
| humoral control mechanisms | monitoring blood levels of substances and correct them |
| neural control mechanism | axons cause hormone release |
| hormonal control mechanism | hormone release is dependent upon other hormone levels |
| is NOT a major endocrine organ, but produces hormones in addition to its major function | kidneys |
| produce the hormones renin and erythropoietin | kidney cells |
| primary function of kidney cells is | excretion of body waste |
| steroid hormones influence cellular activities by | binding to DNA and forming a gene-hormone complex |
| steroid hormones enter cell & form DNA/hormone complex before they | change cellular function |
| preganglionic fibers of sympathetic neurons stimulate adrenal medulla to | produce epinephrine & norepinephrine |
| is either amino acid-based hormones or steroids | chemical classification of hormones |
| __ __ of most body tissues is controlled directly by TH | metabolic rate |
| secretion of parathyroid hormone is a good example of | humoral stimuli |
| stimulus for producing insulin is | high blood glucose concentration |
| transcription of new messenger RNA is a function of | steroid hormones |
| iodine is required for | synthesis of thyroid hormone |
| hypophyseal portal system transports releasing & inhibiting hormones from hypothalamus to | anterior pituitary gland (adenohypophysis) |
| signal that would affect local cells by releasing chemicals into extracellular fluid | paracrine |
| permissiveness is the property in which a hormone __ __ its full effect without another hormone | CANNOT exhibit |
| NOT a true hormone, but, rather, a trophic substance | TSH |
| hypothalamus is considered a __ organ | neuroendocrine |
| protein kinases affect enzymes by | adding phosphate group (phosphorylation) to enzyme |
| "hormone response element" is located on the | cell DNA |
| "hormone response element" represents | site for a hormone to bind |
| water-soluble hormones exhibit | shortest half-life |
| normal endocrine controls can be __ __ by the nervous system | directly overridden |
| POMC is a __ for ACTH | prohormone |
| iodination of thyroid hormones is mediated by | peroxidase enzymes |
| congenital condition that includes mental retardation, short disproportional body size, and a thick tongue and neck is caused by | deficiency of thyroxin |
| osteitis fibrosa cystica is caused by | increase in parathyroid hormone |
| resistin, an insulin antagonist, is a hormone produced by | adipose tissue |
| somatostatin is considered paracrine because it acts on | cells other than those that secrete it |
| alcohol intake inhibits the secretion of ADH, thus the absence of ADH there is | increased urine output |
| sympathetic nerve stimulation causes release of epinephrine and norepinephrine | from adrenal medulla |
| adrenal medulla is a(n) __ stimulated gland | neurally |
| autoimmune response is said to be cause for __ __ diabetes | type I |
| hormones of the thymus gland are essential in | formation of immune cells |
| __ __, main cells of immune system, mature in thymus gland, where they are stimulated by thymosin hormones | T lymphocytes |
| secretion of digestive enzymes is a(n) __ function for the pancreas | exocrine |
| for the pancreas, production of insulin and glucagon is a(n) __ function | endocrine |
| is high at night and low during daylight hours | blood level of melatonin |
| skin, the heart, and the kidneys contain cells or tissues that | produce hormones |
| synthesis & release, or blood levels, of most hormones are regulated by a(n) __ __ | negative-feedback system |
| __ __ for oxytocin are the smooth muscle cells of the uterus and the myoepithelial cells of the mammary glands | target tissues |
| hormones are __ __ the extracellular fluids | secreted into |
| most hormones can be __ __ as either amino-acid based/steroids | classified chemically |
| hormones are __ __ signals that travel in blood or lymph throughout the body | "long-distance" chemical |
| local hormones are released into the __ __ and affect only adjacent cells in the same tissue | extracellular fluid |
| hormones that are derived from __ are called steroids | cholesterol |
| hormones may communicate with their target cells __ __ to an extracellular receptor | by binding |
| hormones may communicate with their target cells by direct __ __ | gene activation |
| a given hormone influences __ __ __ referred to as "target cells" | only certain cells |
| hypothalamus __ __ of the pituitary gland | regulates activity |
| thymic hormones are involved in __ | immunity |
| antagonism has a(n) __ affect | opposite |
Created by:
lfrancois
Popular Anatomy sets