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46 Cards in this Set
- Front
- Back
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endocrine system consists of endocrines(ductless) glands which secrete?
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chemicals called hormones
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each hormones is secreted in response to?
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a particular and specific stimulus, is circulated in the blood throughout the body, and exerts its affects on certain target tissue that have receptors for that hormone
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negative feedback?
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the effects of the hormone often reverse the stimulus and lead to decreased secretion of the hormone
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pituitary gland
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posterior and anterior
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posterior pituitary(neurohypohysis)
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posterior-stores antidiuretic hormone ADH=vasopressin and oxytocin(which are produced by the hypothalamus
ADH increases the amount of water reabsorbed by the kidney tubules, which decrease urinary output maintains normal blood volume and BP by the reaborbtion of water back into the bloodstream |
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posterior pituitary(neurohypohysis) stimulus for ADH release?
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is a decrease in water content of the body-dehydration
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posterior pituitary(neurohypohysis) release of oxytocin
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causes contraction of the uterus and mammary glands
after pregnancy stretching of the cervic generates sensory impulses to hypothalamus-that transmits impulses to the posterior to release oxytocin during breastfeeding the sucking generates sensory impulses from the mothers nipples to the hypothalamus-release of oxytocin causes contraction of the smooth muscle cells of the mammary ducts-this release of milk is called milk ejection or letdown |
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anterior pituitary gland
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synthesizes and secretes growth hormone, thyroid-stimulating hormone, adrenocorticopic hormone, prolactin, follicle-stimulating hormone, and luteinizing hormone
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growth hormone(somatotropin)-anterior pituitary
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increases cell division in mitosis
increases transport of amino acids into cells and their use in protein synthesis GH increases the release of fat from adipose tissue and the use of fat for energy production(important after height has ceased) |
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growth hormone(somatotropin)-anterior pituitary is regulated by?
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growth hormone releasing hormone GHRH and GHIH groeth hormone inhibiting hormone both from the hypothalamus
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growth hormone releasing hormone GHRH is produced during?
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hypoglycemia or when there is high blood level of amino acids(to be turned into protein)
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growth hormone inhibiting hormone GHIH is secreted during?
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hyperglycemia, when carbohydrates are available for energy production and the mobilaization of fat is not necessary
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TSH from anterior pituitary or thyrotropin has only one target?
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The thyroid gland
stimulates the growth of the thyroid and the secretions of T3 (triiodothyronine)and T4 (thyroxine) |
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TSH from anterior pituitary is stimulated by?
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thyrotropin releasing hormone TRH from the hypothalamus when the metabolic rated decreases and there is a need for thyroxine
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Adrenocorticotropic hormone ACTH stimulates the secretion of?
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cortisol and related hormones from the adrenal cortex
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corticotropin releasing hormone CRH from the?
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Hypothalamus-stimulates the release of ACTH\CRH is produced during physical stress situation, auch as injury, exercise, or hypoglycemia
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Prolactin initiates and maintains?
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milk production in the mammary glands
the hypothalamus produces both prolactin-releasing hormone PRH and prolactin inhibiting hormone PIH |
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follicle stimulating hormone FSH is a gonadotropic hormone and the target organs are?
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ovaries and testes
in women-FSH initiates growth of ova in the ovarian follicles and secretion of estrogen by the cells of the follicle in men-FSH initiates sperm production in the seminiferous tubles of the testes |
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FSH is stimulated by the response to gonadotropic releasing hormone in the ?
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hypothalamus
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Luteinizing hormone LH is another gonadotropic hormone whose secretions is increased by?
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GnRh from the hypthalamus
in women-LH causes ovulation and stimulates the ruptured ovarian follicle to become the corpus luteum and begin secreting progesterone as well as estrogen in men-LH stimulates the secretion of testosteron by the interstitial cells of the testes |
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thyroid gland consistes of 2 lobes connected by a middle piece called the?
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central isthmus, the gland is located on the front and sides of the trachea, just below the larynx
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3 hormones are produced by the thyroid gland?
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T3, T4 are produced in the thyroid follicles, reguire iodine(T4 has 4 iodine atome and T3 has 3 iodine atoms)
and they both have the same functions Calcitonin is the thrird hormone-produced in the parafollicular cells |
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T4 & T3 increase?
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energy production and protein synthesis
increase cellular respiration of glucose and fatty acids which increase the metabolic rate-that is energy, and heat production they are important for daily regulatitors of metabolic rate-functioning of the heart, brain, muscles and virtually all organs essential for normal physical growth, mental development, and reproductive maturation |
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direct stimulus for secretion of T# & T4 is?
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TSH from the anterior pituitary gland:
a decrease in metabolic rate(energy production), is detected by hypothalamus, which secretes TRH. TRH stimulates the anterior pituitary gland to secrete TSH, which stimulates the thyroid to increase secretions of T3 and T4, which increase energy production to raise metabolic rate...as it rises a negative feedback decreases the secretion of TRH from the hypothalamus until the metabolic rate is decresed |
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the thrid hormone Calcitonin targets the?
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bone tissue and is important during childhood when bone growth excelerates.
It inhibits reabsorption of calcium and phosphate by the osteoclasts, thereby lowering the blood levels of these minerals and retaining them in the bones |
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the thrid hormone Calcitonin -the one function has 2 important results
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1. the maintenance of normal blood levels of calcium and phoshate
2. the maintenance of a strong, stable bone matrix |
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the thrid hormone Calcitonin is stimulated by
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hypercalcemia(high blood calcium level)..when the blood calcium level rises, increased calcitonin ensures that no more will be removed from bones until need for blood calcium returns
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Parathyroid glands
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4-2 on the back of each lobe of the thyroid
the hormone produced is the PTH which is an antagonist to calcitonin;it maintains normal blood levels of clacium and phosphate |
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Parathyroid glands target organs
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bones, small intestines and kidneys
PTH increases the reabsorption of calcium and phosphate fromt he bones to the blood, which raises their blood levels. by the small intestines from food is also increased by PTH through the action of activating Vit. D(calcitriol) in the kidneys PTH increases the reabsorption of calcium in the kidneys and the excretion of phosphate...the overall effect of PTH is to raise the blood calcium level and lower the blood phosphate level |
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Parathyroid glands-PTH is stimulated by
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hypocalcemia and is inhibited by hperclcemicalcium ions in the blood are essential for normal excitability of neurons and muscle cells and for the process of blood clotting
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Adrenal Glands-2 (also called supradrenal) are located one on top of each?
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Kidney
each adrenal gland consists of an inner adrenal medulla and an outer adrenal cortex |
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Adrenal Medulla
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cells are chromaffin cells
they secrete epinephrine and norepinephrine collectively called(catecholamines) and are sympathomimetic(mimicking the sympathetic nervous system) |
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secretion of norepinephrin and epinephrine hormones from adrenal medulla is stimulated by?
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sympathetic impulses from the hypothalamus in stressful situations
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of the 2 hormones from adrenal medulla-epinephrine and nprepinephrine
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epinephrine is secreted in larger amounts-4 times as much as norepinephrine and has many effects;
increases heart rate and force of contraction stimulates vasoconstriction in skin and most viscera vasodialtion in skeletal muscles dialtes bronchioles decrease peristalis stimulates the liver to convert glycogen into glucose increases the rate of cell respiration |
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the most significant function of norepinephrine is to cause?
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vasoconstriction in the skin and most viscera, thereby raising blood pressure
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Adrenal Cortex secretes 3 types of steroid hormones?
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mineralocoticoids, glucocorticoids and sex hormones
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aldosterone is the most abundant of the mineralcorticotoids of the adrenal cortex and its target organ is?
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kidneys-aldosterone increases the reabsorption of sodium ions and the excretion of potassium ions by the kidneys tubules. Sodium ions are returned to the blood and potassium ions are exreted-this process reduces the risk of acidosis because this prevents the accumulation of hydrogen ions which leads to acidosis
it is impotant for maintenance of normal blood volume and blood pressure |
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aldosterone is stimulated in many ways?
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low blood sodium level
high potassium level dehydration that lowers blood pressure low blood pressure activates the renin-angiotensin mechanism of the kidneys |
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corticol is the most abundant of the glucocorticoids and has many target tissues.
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cortisol stimulates gluconeogenesis(the conversion of tryglycerides, lactic acid and some amino acids to glucose) in the liver
increases lipolysis and protein breakdown to liberate fatty acids and amino acids for gluconeogenesis. the goal is to increase capabilities for energy production-by providing secondary energy source to most cells-corticol ensures that whatever glucose is available for the brain(glucose spaing effect) has an antiimflammatary effect-it blocks effects of histamine and stabilizes lysomes in cells prevents tissue breakdown and limits the inflammation process to what is useful for tissue repair |
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excess crotisol has damaging effects:
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it raises blood glucose levels
decreses the immune response delays healing of damaged tissue |
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the direct stimulus for cortisol is?
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ACTH from the anterior pituitary gland
it is a stress hormone=any type of physiological stress(injury, diseases, malnutrition) stimulates the hypothalamus to secrete CRH CRH increases secretion of ACTH by the anterior pituitary which increases cortisol secretion of the adrenal cortex |
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Pancreas-the endocrin portions are called islets of the Langerhans(pancreatic islets)they contain?
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alph cells-produce glucagon
beta cells-produce insulin delta cells-in the islets secrete somatostatin, which inhibits secretion of both insulin and glucagon |
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the functions of glucagon are all related to?
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energy production
glucagon stimulates the liver to catabolize glygogen to glucose(glycogenolysis) and to increase gluconeogensis to use for fats and excess amino acids for energy production-overal effect is to raise blood glucose level for cellular uptake and respiration |
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the secretion of glucagon from apha cells is stimulated by?
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hypoglycemia-a low blood glucose level
insulin decreases the blood glucose level by increasing the use of glucose for energy, promoting storage of excess glucose and decreasing energy production from other food sources insulin secretion is stimulated by the hyperglycemis(high blood glucose level |
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Urine tests
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to measure the amount of hormones in a 24 hour period:obtain a urine specimen container from lab-opaque
find out if it needs to be on ice ask Pt. to urinate and discard-this is considered the starting of the 24 hr test at the end ask Pt to void and save urine it is labeled(the entire collection) and sent to lab place signs to instruct Pt and caregivers to save urine-the time of the test-start and end time replace ice |
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nuclear scannin
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to deterime nodules or tumors in thyroid
radioactive material is injected or iodine is taken orally the material is taken up by the thyroid after a specific time the thyroid is scanned with a scintillation camera the scan shows hot spots-which are nodules that are not malignant or cold spots(areas that do not take up material) which indicate malignancy-cold spots can be biopised to confirm diagnosis |
