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152 Cards in this Set
- Front
- Back
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autocrine signaling is when the same cell is stimulated
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a cell secretes a hormone or chemical messenger (called the autocrine agent) that binds to autocrine receptors on the same cell, leading to changes in the cells
think masturbation...stimulates itself :P |
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paracrine signaling occurs between cells that are placed close to one another
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know
think para-meter...stimulates things in the vicinity |
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endocrine signaling involves distance between cells
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know
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endocrine capable organs include
TPTP GHOKH |
each organ is capable of synthesizing and secreting one or more hormones
-hypothalamus -pituitary -testes -ovaries -pineal gland -kidneys -gastrointestinal glands -heart -thymus |
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hormones comes in two types
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steroids
peptides |
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hypothalamus
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master control gland in the brain
-controls pituitary gland -negative feedback by cortical hormones |
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pituitary has two sections
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anterior
posterior |
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hypothalamus secretes compounds into hypophyseal portal system
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link hypothalamus to anterior pituitary in the brain
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hormones enter portal system, bind to anterior pituitary receptors and trigger release of other hormones
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know
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hypothalamus secretes CRH and vasopressin
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CRH acts on anterior pituitary to release ACTH
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what are the hormones released by the anterior pituitary?
FLAT PEG |
Follicle stimulating hormone
Luteinizing hormone ACTH Thyroid stimulating hormone Prolactin Endorphins Growth Hormone |
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GnRH -->
gonadotropin-releasing hormone |
LH and FSH
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GHRH -->
growth human releasing hormone |
GH
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PIF -->
prolactin inhibitory factor |
prolactin
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TRH
thyroid releasing hormone |
TSH
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CRF --->
corticotropin-releasing factor |
ACTH
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with the past few cards...the question part was the hypothalamus hormone released to stimulate the release of the "answer" from the anterior pituitary gland
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:P
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ACTH causes adrenal glands to release/increase the levels of _____ in the blood
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cortisol
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cortisol can have negative feedback on the hypothalamus and anterior pituitary from secreting...
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CRF (hypo)
ACTH(ant. pit.) |
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posterior pituitary
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hypothalamus stimulates post. pit. to release oxytocin and ADH
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ADH = vasopressin
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know
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anterior pituitary hormones can be categorized as either direct or tropic
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know
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direct hormones will bind to ____ on target organs and have a ___ effect
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receptors
direct effect |
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tropic hormones also bind to receptors on organs and cause the release of ____ hormones
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effector hormones
-act as an intermediate |
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direct hormones include...
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PEG
prolactin endorphins growth hormone |
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growth hormone
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promotes growth of bone and muscles
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growth hormone prevents glucose uptake in non-growing tissues and stimulates the breakdown of fatty acids
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know
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gigantism =
dwarfism = |
excess GH release
inexcess GH release |
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acromegaly
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when hands, feet, head still grow after puberty
-although plates sealed with bones, GH still has an effect on smaller bones |
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prolactin is important in females since it stimulates ___ production
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milk production in mammory glands
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endorphins
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direct effect on pain modulation
-decrease the sense of pain |
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tropic hormones include...
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FLAT
FSH LH ACTH TSH |
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FSH/LH affect the ovaries and testes
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know
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TSH stimulates thyroid to take up ___
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iodine
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ACTH regulated by CRF
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ACTH encourages adrenal glands to release glucocorticoids
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oxytocin is secreted during...
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childbirth
-allows for coordinated contraction of uterine and smooth muscle -secreted also from suckling --> lead to milk production also |
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ADH used to regulate blood osmolarity
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functions with the collection duct to reabsorb fluids
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osmolarity differences are sensed by the ____ while blood volume is sensed by ____
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osmoreceptors = osmolarity
baroreceptors = blood volume |
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thyroid gland is controlled by anterior pit(TSH) and hypothalamus(TRH)
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know
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thyroid has two major functions...
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setting basal metabolic rate
calcium homeostasis |
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basal metabolic rate is controlled through release of ___ and ___
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thyroxine
triiodothyronine (thyroid hormones) |
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calcium levels are controlled using calcitonin
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know
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thyroxine = T_
triiodothyronine = T_ |
T4
T3 |
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T4 and T3 are both produced by iodination of amino acid tyrosine in the follicular cells of the thyroid
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know
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t4 means it has 4 iodines attached...etc
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know
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increasing T3 and T4 levels will lead to in/decreased cellular respiration
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increased cellular respiration
-cause increased amt of proteins and fats to turnover -speeds up synthesis and degradation of both |
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high plasma levels of thyroid hormones will decrease TSH/TRH release
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know
-negative feedback |
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hypothyroidism
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deficiency in iodine or inflammation of thyroid can cause this
-thyroid does not secrete enough hormones or none at all |
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hypothyroidism symptoms
L/T/RH/W |
lethargy
decreased body temperature slowed respiratory and heart rate weight gain |
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cretinism is disorder that results in mental retardation or delayed development
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results from hypothyroidism in young children
-lack of iodine also |
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hyperthyroidism
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excess release of thyroid hormones
-results from tumor |
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symptoms of hyperthyroidism
A/T/RH/W |
-increased activity
-increased body temperature -increased heart and respiration rate -weight loss |
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goiters can form with both hypo and hyperthyroidism
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know
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within the thyroid, there are
-follicular cells that produce thyroid hormones -C-cells that produce calcitonin |
know
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calcitonin decreases plasma calcium levels by...
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1. increase kidney excretion(urine)
2. decreased gut absorption 3. increase bone storage |
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high levels of calcium in blood recruit calcitonin production and storage
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know
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parathyroid glands produce PTH
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antagonistic hormone to calcitonin
-increases plasma calcium levels -decreases excretion(kidney) -decreases storage(bone) -increases reabsorption(gut) |
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PTH activates vitamin D which is required by gut to absorb calcium
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know
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PTH is subject to feedback inhibition
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as calcium levels rise in blood, PTH levels decrease
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adrenal glands are located on top of the kidneys
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have adrenal cortex and adrenal medulla
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adrenal cortex secretes corticosteroids due to ACTH stimulation
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all corticosteroids are steroid hormones
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corticosteroids fall into 3 categories
1. glucocorticoids 2. mineralocorticoids 3. cortical sex hormones |
know
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glucocorticoids
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regulate glucose levels
-affect protein metabolism |
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two types of glucocorticoids
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1. cortisol
2. cortisone |
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cortisol and cortisone increase gluconeogenesis and decrease protein synthesis
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they can also decrease inflammation and immunological responses
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cortisol is usually the stress relieving hormone
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know
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mineralocorticoids
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regulate mineral balance
-control salt balance with kidneys |
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aldosterone = mineralocorticoid
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released into kidneys to reabsorb Na and H2O
-blood volume regulator also |
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aldosterone linked to control over K and H+ ions
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aldosterone enhances the secretion of K+ and H+ into tubule
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potassium and hydrogen excreted through urine
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know
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aldosterone secretion controlled by angiotensin release from the renin-angiotensin system
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know
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decreased blood volume causes juxtaglomerular cells of kidneys to secrete renin --> activates angiotensinogen to angiotensin I
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angiotensin I converts to angiotensin II --> stimulates adrenal cortex --> secretion of aldosterone
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negative feedback with aldosterone and blood volume levels
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know
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ACE inhibitors prevent angio I --> II which lowers blood volume...
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good prescription for high BP patients
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cortical sex hormones
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adrenals capable of making male sex hormones = androgens
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adrenal medulla is responsible for the production of fight/flight sympathetic hormones....
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epinephrine
norepinephrine |
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nor/epinephrine are both ___ hormones
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peptide hormones
-belong to catecholamines |
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epinephrine increases conversion of glycogen(stored) to glucose(useable) in the liver and muscle
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also increase metabolic rate
-increased HR, resp. rate -increased blood flow -vasodilation in muscles -vasoconstriction in digest. tract, kidneys and skin |
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pancreas contains islets of langerhan
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has 3 distinct cell types
1. alpha 2. beta 3. delta |
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alpha cells secrete glucagon
beta cells produce insulin delta cells make somatostatin |
know
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glucagon is a hormone that is ant/agonist to insulin
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antagonist
-works opposingly |
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glucagon is secreted when famined/hungry
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glucagon stimulates degradation of fats/proteins and conversion of glycogen to glucose
-promotes gluconeogenesis |
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CCK will increase glucagon from alpha cells
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know
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insulin is secreted to encourage muscle and liver cells to uptake glycogen
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glucose --> glycogen storage
-insulin promotes fat and protein synthesis |
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insulin can cause hypoglycemia =
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low blood glucose levels
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diabetes mellitus is...
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characterized by lowered/no insulin production and characterized as hyperglycemia
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hyperglycemia =
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high blood glucose levels
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high glucose levels are secreted through urine
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know
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diabetics report polyuria =
and polydipsia |
increased urination frequency
increased thirst |
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two types of diabetes
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type 1
type 2 |
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type 1 =
causes |
insulin dependent
-caused by autoimmune destruction of beta cells -require insulin injections |
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type 2 =
causes |
non-insulin dependent
-result of insulin resistance at receptor site -caused by high sugar diets -weight related |
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somatostatin
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inhibitor of both glucagon and insulin
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somatostatin is released due to high glucose levels in blood and high amino acid concentrations
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know
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testes
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site of spermatogenesis
-FSH and LH stimulate this |
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FSH stimulate sertoli cells
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FSH is necessary for sperm maturation
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LH causes interstitial cells to produce testosterone
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major sex hormone
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testosterone is important for male sex differentiation, embryonic development, maintenance of secondary sex characteristics
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testosterone provides negative feedback on FSH and LH and GnRH
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if lack testosterone receptors, can not be affected by testosterone
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know
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androgen insensitivity syndrome
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when a genetic male (XY) has female sex characteristics
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ovaries are under FSH and LH
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know
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ovaries secrete estrogen and progesterone
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know
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estrogen
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secreted in response to FSH and LH secretion
-develop 2ndary sex characteristics |
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estrogen is responsible for thickening of the endometrium
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know
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in embryo, estrogen syimulates development of female reproductive tract
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know
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estrogens are secreted by ovarian follicles and corpus luteum
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know
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progesterone
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secreted in response to LH and FSH
-released from corpus luteum |
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progesterone is responsible for development and maintenance of endometrium...but not its generation
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know
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by end of 1st trimester progesterone is supplied by placenta and corpus luteum ceases production
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know
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menstrual cycle
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shedding of endometrial lining
-controlled by estrogen and progesterone |
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stages of menstruation
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1. follicular phase
2. ovulation 3. luteal phase 4. menstruation |
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follicular phase
-begins when menstrual flow stops |
know
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lowered GnRH secretion =
lowered LH/FSH secretion |
beginning of follicular stage
-levels remain rather low in this stage |
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FSH and LH work together to stimulate follicle production
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know
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follicles begin to produce estrogen, having (-) feedback on GnRH, LH, and FSH
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these hormones level off
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estrogen is main hormone in effect with follicular phase
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know
-aka estradiol |
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estrogen works to regrow endometrial lining
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know
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estrogen is capable of + and - feedback effects
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know
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late follicular phase = follicles secreting estrogen
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estrogen levels increase and positively feedback on GnRH, LH and FSH (spike in levels)
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ovulation is noted by a SURGE in LH hormone
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high levels of LH stimulate ovulation phase to occur
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luteal phase begins when high LH levels rupture follicle to form corpus luteum
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corpus luteum secretes progesterone
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estrogen helps maintain uterine lining while progesterone maintains it for implantation
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know
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progesterone levels and estrogen levels are high during luteal phase
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negative feedback on GnRH, LH, FSH
-prevent multiple ova development in same cycle |
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contraceptive pills include progesterone and estrogen to inhibit ovulation by preventing LH/FSH release
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know
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menstruation
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if implantation does not occur, hCG will not be produced
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without hCG to stimulate corpus luteum, progesterone levels deline and uterine lining shed
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loss of high estrogen and progesterone allow GnRH to start next cycle
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if fertilization occurs, corpus luteum will be maintained by hCG
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hCG is secreted by blastocyst and developing placenta
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during 1st trimester, estrogen and progesterone are secreted by corpus luteum keep the uterine lining in place
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know
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2nd trimester, hCG levels decline but progesterone/estrogen rise since secreted by placenta
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know
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high estrogen and progesterone negatively feedback on GnRH during pregnancy
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know
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menopause
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45-55yoa
-decreased response of ovaries to FSH and LH -results in decreased estrogen and progesterone levels |
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menopausal women will have high levels of FSH and LH since not negatively inhibited by estrogen or progesterone
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know
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pineal gland
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located in brain
-secretes hormone melatonin |
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melatonin involved in circadian rhythm
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know
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gastrointestinal tract...contains glandular tissue in both stomach and intestine
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gastrointestinal peptides include
-secretin -gastrin -CCK |
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kidneys produce erythropoietin
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stimulates bone marrow to produce RBC
-secreted in response to low oxygen levels in blood |
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heart releases atrial natriuretic peptide
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helps regulate salt and water balance
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thymus releases thymosin
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important for proper t-cell development and differentiation
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hormones are classified into three main groups
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1. peptide hormones
2. steroid hormones 3. amino acid-derived hormones |
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peptide hormones
-made up of amino acids |
small to large size range
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peptide hormones (smaller than polypeptides) transported to golgi and modified(activated) and guide in right direction
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know
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peptide hormones are charged....can not cross the phospholipid membrane
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bind to receptors on cell surface
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peptide hormones act as 1st messengers
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stimulate the production of 2ndary messengers (cAMP)
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adenylate cyclase promotes ATP ---> cAMP
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cAMP can bind to intracellular targets like proteins or DNA to cause changes
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phosphodiesterase terminates cAMP's signal cascading
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know
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steroid hormones
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derived from cholesterol
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steroid hormones, derived from a non-polar molecule, are capable of traveling through cell membrane
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know
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steroid hormones have intracellular or intranuclear receptors
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know
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upon steroid hormone binding to receptor, it dimerizes and bonds directly to DNA to alter transcription by in/decreasing transcription depending on hormone and gene
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dimerize = 2 identical molecules bound together
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effects of steroid hormones are longer lived than peptides
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they alter amount of mRNA and protein present in cell
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however, it takes longer to see effects of steroid hormones vs. peptide hormones
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due to transcription/translation are not immediate
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amino acid-derivative hormones
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less common
-epinephrine -norepinephrine -thyroxine |
