Anatomy & Physiology Ch.16 Endocrine System Marieb Flashcards

Terms Definitions
Target cells
nervous signals get to destinations quicker, but endocrine hormones have longer effects
endocrine glands vs. exocrine glands
endocrine have no ducts - release hormones into surrounding tissue
list the endocrine glands
pituitary, thyroid, parathyroid, adrenal, pineal, thymus glands
which gland is a neuroendocrine organ?
which endorcrine glands are in the brain? (3)
pineal, hypothalmus, pituitary
which endorcrine glands are in the neck? (2)
thyroid, parathyroid
which endocrine gland is near the heart?
thymus gland
which endocrine glands are in the thoracic cavity? (2)
adrenal glands (2), pancreas
which endocrine glands are in the gonads?
ovaries or testes
what other cells produce hormones?
adipose cells produce LEPTIN, and there are pockets of hormone-producing cells in the walls of the small intestine, heart, stomach, & kidneys (but only affect their immediate area.)& tumor cells (produce hornones in extreme amounts)
most hormones are made of ______?
ammino acids
are ammino acid-based hormones hydophilic or hydrophobic? (& what does this mean/effects of this?)
hydophilic = H2O soluble = CAN'T go through cells' phospholipid bilayer
steroid hormones are made of?
cholesterol (lipid/fat based) = fat soluble = can get across the phospholipid bilayer easily
eicosanoids & their purpposes
leukotrines (inflamatory mediators) & prostaglandins (pain mediators)
target cells
what the hormones affect - all other cells ignore the hormones all around them
which ammino-acid hormone does not use the 2nd messenger system to get into cells?
thyroid hormone
how do ammino acid based hormones get into cells?
2nd messenger system
explain the 2nd messenger system
1. hormone binds to its receptor protien, 2. which binds inside the cell membrane to an inactive G-protien. 3. The GDP inside the G-protien is kicked out by GTP, so the G-protien turns on (light switch). 4. Now the activated G-protien moves along membrane & binds to ADENYLATE CYCLASE (2 either stimulate or inhibit it). 5. GTP atachaced to G-protien is hydrolyzed in to GDP again. 6. adenylate cyclase makes cAMP from ATP. 7. cAMP triggers cascade of RXions by binding with protein kinase - starting with the activation of protein kinase (this starts a number of reactions.)
what does "kinase" mean?
that something is phosphorylated
oxytocin, anti-diuritic hormone, catacholamines, & thyroid-releaseing hormone use what process to get into cells?
PIP-Calcium mechanism (also a 2nd messenger process)
steroids & thyroid hormone use what method to get into the cell?
direct gene activation mechanism
explain the process of the direct gene activation mechanism
they pass right through the phospholipid bilayer and into nucleus, binds to a receptor, binds to DNA & starts transcription of a certain gene, mRNA is transcribed, leaves the nucleus & mRNA directs synthesis of a specific protein.
hormone-receptor interaction depends equally on 3 factors - what are they
1. blood levels of hormone 2. # of receptors in target cells 3. affinity (strength) of bond between hormone & receptor
when target cells form more receptors in response to rising blood levels of a specific hormone
when target cells are desensitized to a hormone b/c of its high concentrations - they respond less vigorously
half-life of hormones & 2 examples
the length of time for hormone BLOOD levels to be reduced by 1/2 - (from a couple minutes to a week) H2O-soluble - (epinephrine) have a short 1/2 life. Fat-suloble (steroids) have a long 1/2 life
3 mjor mechanisms for hormone release (list them)
1. humoral stimuli 2. neural stimuli 3. hormonal stimuli
humoral stimuli & ex.
when glands secrete hormones in direct response to changing blood levels of certain critical ions & nutrients ("Humor" = body fluid) EX: when calcium levels get too high, calcitonin gets released
neural stimuli & ex.
when nerve fibers stimulate glands to release hormones EX: adrenal gland innervated by sympathetic nervous system 2 release epinephrine
hormonal stimuli & ex.
most glands are under control of hormone released by hypothalmus - EX: pituitary glad makes 6 hormones - completely under control of the hypothalmus's FSH releasing hormone, etc.
pituitary gland relseases what 9 hormones?
1. ACTH 2. TSH 3. LH 4. FSH 5. PRL 6. GH 7. MSH 8. ADH 9. Oxytocin
what is the stalk attaching the pituiatary to the hypothalmus?
what are the 2 lobes of the pituitary
posterior lobe (neuronal tissue), & anterior lobe (glandular tissue)
posterior lobe of pituitary does what?
storage place - stores oxytocin & ADH (these are produced in the hypothalmus
"adeno" means what?
what hormones are from the anterior lobe of the pituitary? (6)
1. ACTH 2. TSH 3. LH 4. FSH 5. PRL 6. GH
pro-opiomelanocortin - a precursor that can be split to produce othe hormones - MSN & natural poiates of the brain
melanocyte stimulating hormone -more of a neuro-transmitter - to modulate our appetite - (in OTHER animals - it stimulates the melanicytes to produce melanin pigment)
tropic hormones (tropins) & pituitary gland examples
stimulate their target cells - regulate the secretory action of other endocrine glands -all affect their target cells via an AMP 2nd messenger system EX's: TSH, ACTH, FSH, LH
growth hormone
produced in somatotrophs - stimulates ALL the body's cells 2 increase in size & start mitosis - major targets = bones & skeletal muscle. = increased muscle mass & elongation = anabolic hormone - also has insulin-like activity (breaks down fats for fuels & breaks down glycogen. increases blood sugar levels
glucose-spearing effect or diabetogenic effect
causes a transient hyperglycemia - (high blood sugar level) (opposite of what insulin does)
GH under control of what 2 hormones?
GHRH & GHIH (or somatostatin)
when is the most GH released?
when you're sleeping
when do GH levels peak?
in adolescence (growth spurts)
Hypersecretion of GH is
giantism = during active epipyseal plates are still open - can get up to 8 ft tall - normally these people have heart problems - valvular failures/congestive heart failure - normally die young
hypersecretion of GJ AFTER epipyseal plates are closed
acromegaly - large hands, feet, & face - thickening of the toungue & jaws - tumor needs to be removed to treat, but all growth effects are permanent
hyposecretion of GH
pituitary dwarfism - no taller than 4 feet - typically there are failures of all hormones in the anterior pituitary = no sexual maturation, etc. If ID'd in time, can get hormone replacement therapy, etc.
Thyrotropin - stimulates thyroid gland. Release of TSH triggered by TRH (thyrotropin-releasing hormone) -
corticotropin - stimulates the adrenal gland to produce its steroids
follicle stimulating hormone - stimulates gamate production (eggs & sperm)
Lutenizing hormone - in female - triggers maturation of ovarian follicles & promotes ovulation, promotes sythesis of extrogen & progesterone. In males - stimultes production of testosterone
Prolactin - stimuates milk production in breasts - this is a supply & demand hormone - not understood in males
hypersecretion of PRL
hyperprolactinemia - dripping milk when you're not feeding a baby
stimulates uterine contractions
anti-diuretic hormone- prevents swings in H2O balance, helps body avoid dehydration & H2O overload
inhibiting ADH producion w/alcohol causes what?
HUGE amount of urine output (5L/day) & dehydrates you
diabetes insipidus
output of huge amounts & intense thirst is pathopneumonic ("diabetes" = overflow "insipidus" = tasteless)
diabetes mellitus
"Diabetes" = overflow "mel" = honey sweet urine = huge amounts of blood glucose lost in urine
what can cause diabetes insipidus
blow to the head that damages the hypothalmus or posterior pituitary
thyroid gland
in the neck - largest pure endocrine gland in the body - 2 sides connected by an isthmus
thyroid hormone is the only tissue in the body that does what?
selectively uptake iodine from the blood (in a 6-step reaction)
Thyroid hormone made up of what?
2 iodine-containing amine hormones - T4 (Thyroxine) & T3 (Triiodothyronine)
Target organs of the thyroid hormone?
everything in the body EXCEPT adult brain, spleen, testes, uterus, & thyroid gland itself
how is thyroid hormone produced?
1. thyroglobulin made in rough ER & sent 2 colloid. 2. Iodide brought in cell by active transport - oxidized to IodiNe 3. attaches to tyrosine - forms MIT & DIT. 4. MIT & DIT couple & become T3 or T4. 5. T3 & T4's are endocytosed (popped out) in a lysosome. 6. T3 & T4 leave lysosome, leave cell, and enter bloodstream
Iodine deficiency causes?
excessive colloid buildup = goiter (in the neck)
hypothyroid syndrome
untreated = myxedema = the fat pads behind your eyes swell & your eyes pop out - the thyroid will give up & atrophy if not treated
hypothyroid in infants - mantal retardation - child won't grow right - developmental abnormalities mentally are not reversable - from lack of meternal dietary iodine or problem with gland development
grave's disease
Hyperthyroidism - increased metabolic rate - rapid heartrate - removal of the tyroid gland - ingest Iodine 131 (radioactive - only the thyroid cells pull it in and it gets destroyed
none of 2 hormones responsible for blood CA regulation - when the levels are too high - calcitonin is released - stimulates osteoBlasts (bone builders) to pull Ca out of blood and deposit into bones
parathyroid glands
located posterior (or just inside) the thyroid gland - secretes PTH - stimulates oseoClasts when blood Ca levels are too low
parathyroid hormone - stimulates osteoClasts to break Ca out fo bones and into the blood
usually b/c of accidental removal during surgery - you're jumpy.
if you don’t have enough parathyroid hormone - not enough Ca in blood - muscles can't contract b/c of Ca deposits in the muscles = deadly
when you don't have enough Ca in diet, so bones are broken down & fracture all the time
adrenal gland (or suprarenal) - name the 2 sections
inner adrenal medulla and outer adrenal cortex
adrenal cortex produces… (3)
mineralocorticoids (adosterone), Glococorticoids (cortisol), and gonadocorticoids (androgens that’s later change into testosterone/estrogen)
adrenal medulla produces… (2)
epinepherine & norepinepherine
regulate mineral salt (electrolyte) conentrations in extracellular fluids - aldosterone is the most potent & is 95% of mineralocorticoids produced - maintains sodium balance in body
describe the mechanisms that regulate aldosterone secretion
1. kidneys get excited when blood pressure & volume declines & release Renin in to blood. 2. renin breaks off angiotensiogen, which ACE converts into Angiotensin I, and then into Angiotensin II (which stimulates aldosterone release). 3. more Na+in blood casue more aldosterone to be released, more K+ in blood limits aldosterone release. 4. when you are stressed, hypothalmus secretes more CRH & higher ACTH levels cause more aldosterone secertion also. 5. ANP secerted by the heart inhibits the release of aldosterone.
hypersecretion of aldosterone
Aldosteronism - from an adrenal tumor - excessive Na+ & H2O retention (edema)& loss of K+ ions - b/c loss of K+ = muscle weakness & eventual paralysis
hyposecretion of aldosterone (& low mineralocorticoids)
Addisons disease - deficit output of mineralocorticoids & glucorticoids - brozing of the body = bronze diabetes - severe dehydration & hypotension
released in response to stress - antiinflammatory - under control of ACTH - enhanes action of epinepherine - higher blood pressure, etc. - rise in blood levels of glucose, fatty acids, and ammino acids - slows healing - immunosupressive - usually from an adrenal tumor
long-standing glucorticoid excess produces?
Cushing's syndrome - moon face - more fat at the buffalo hump - more fat on stomach & neck - immunosupressed -
excessive glucocorticoids = ?
cushings syndrome
hypO-mineralocorticoids = ?
addison's disease
androgenital syndrome
hypersecretion of gonadocorticoids - females look like males - little boys mature early
adrenal medulla produces… (2)
hypersecretion of chatecholamines
pheochromocytoma - uncontrolled sympathetic nervous system activity - hyperglycemia, higher metabolic rate, rapid heartbeat, nervousness & sweating
breaks down glycogen - (& other fats) 2 increase blood sugar
produced by beta cells - produced as 83 ammino acids & is broken down to 51 in a chain - enhances membrane transport of glucose -
diabetes mellitus
hyposecretin or hypoactivity of insulin - blood glucose constantly high, but glucose can't get into the cells -
excessive urination
excessive thirst
excessive hunger & food consumption
brain disorientation, convulsions, inconsciousness & death
3 gonads hormones
estrogen, progesterone, testosterone
pineal gland hormone
melatonin - sleep/wake cycles - also has a role in
Thymus -
stimulates production of T lymphocytes
"red marker" - signals to bone marrow ro increase production of the red blood cells
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