endocrine ch18 Flashcards
what does GAS stand for and name the phases
general adaptation syndrome
- alarm phase
- resistance phase
- exhaustion phase
describe the alarm phase (GAS) and what is the dominant hormone during this phase
1st phase
quick response to stressor from the sympathetic part of the autonomic nervous system.
epinephrine is dominant hormone during this phase
- energy reserves are mobilized in glucose form
- body preps to deal with stressor by fight of flight
describe resistance phase and what is the dominant hormone during this phase
2nd phase
person enters this phase if the stress last longer than a few hours
glucocorticoids are the dominant hormone during this phase
energy demand during this phase is higher than normal. Nervous tissue has high demand for energy requiring glucose
describe the exhaustion phase
3rd phase
When resistance phase ends, homeostatic regulation breaks down and this phase begins.
inability to produce glucocorticoids
inability to sustain endocrine and metabolic adjustments from resistance phase
endocrine disorder of underproduction of GH
pituitary growth failure / pituitary dwarfism in children
overproduction of GH
gigantism in children and acromegaly (excessive growth) in adults
underproduction of parathyroid hormone (PTH)
hypoparathyroidism
muscular weakness, dense bones due to low blood CA+ levels, neurological problems
overproduction of parathyroid hormone (PTH)
hyperparathyroidism
high blood CA+ levels leading to neurological, mental, and muscular problems
weak and brittle bones
underproduction of insulin leads to
type 1 diabetes
- impaired glucose usage and depending on lipids for energy
Underproduction of glucocorticoids
addisons disease
- inability to tolerate stress
-inability to maintain normal blood glucose levels
overproduction of glucocorticoids
cushing disease
- excessive breakdown of tissue proteins and lipid reserves
- impared glucose metabolism
type 1 diabetes
problem with insulin
- inadequate insulin production by pancreatic beta cells
- person needs insulin to live and many injections of it daily/insulin pump
- usually develops in children/young adults
- born w. it
type 2 diabetes
insulin resistant
- most common form of diabetes mellitus
- most people produce normal amount of insulin but their tissues don’t respond properly (insulin resistance)
- assc. with obesity
- can be undone with diet and weightloss
Main growth hormones and what does it affect
GH (growth hormone), thyroid hormones, insulin, PTH, calcitrol, reproductive hormones
- affects protein synthesis, cellular growth in children
- helps maintain normal blood glucose levels in adults
what regulates blood pressure and blood volume
pituitary and adrenal glands
cells in heart and kidneys
endocrine cells in the heart wall detect stretching due to _____ making them secrete ___
increased blood volume / blood pressure and they secrete atrial natriuretic peptides
increase/secretion of ANP (atrial natriuretic peptides) promote…..
promote Na+ and water loss at kidneys
decrease blood volume/pressue is detected by ….
endocrine cells in kidneys
endocrine cells in kidneys release _____ for ___ fluid retention
EPO and Renin to increase fluid retention
renin makes ____ + ___ to be produced
ADH and aldosterone
the heart produces which hormone (assc. with BP/ volume)
Atrial natriuretic peptides (ANP)
- lowers BP/Blood volume
- it releases Na+
-opposite of ADH + aldosterone
when is ANP released? and what do target organ kidney do?
when Blood volume/pressure is too high in response to the stretching of atria
kidneys inhibit Na+ reabsorption and renin release
basically releases Na+ and H2O to decrease blood volume/pressure - drink less water and dilate blood vessels
the kidneys produce which hormone (assc. with BP/ volume)
EPO (eryhropoietin) in response to hypoxia and this activates renin
renin then releases adh/aldosterone telling the kidneys to hold onto water/NA+
so blood vessels constrict and you drink more water
when is EPO released? and what do target organ red bone marrow do?
when Blood volume/pressure is too low in response hypoxia
red bone marrow then stimulates production of more red blood cells
3 possible outcomes of 2 or more hormones affecting cell at the same time
(3 hormone interactions)
- permissiveness
- synergism
- antagonism
permissiveness
1 hormone can not exert its effect without another hormone being present
- 1 hormone needs a partner
synergism
2 or more hormones produce same effect (but AMPLIFIED) at target cell
antagonism
hormone opposes action of another hormone
- insulin vs glucagon fight at the cell
what type of gland is the pancreas
exocrine + endocrine
what does the pancreas produce
digestive enzymes, insulin, glucagon
does the pancreas or the pancreatic islet secrete glucagon/insulin/ somatostatin??
pancreatic islet!
alpha cells in the pancreatic islet secrete ____ when blood sugar levels are low
glucagon
note- glucagon goes to where glucose is stored in the body and tells it to come out
Beta cells in the pancreatic islet secrete ____ when blood sugar levels are high
insulin
blood sugar is the same as
glucose
delta cells in the pancreatic islet secrete ____
somatostation (growth hormone inhibiting hormone
after a meal theres an increase of ____ and the pancrease produces ___
increase blood glucose levels after eating and the pancreas produces insulin so cells use glucose as energy
where are the adrenal glands located at and how many categories of hormones are there?
atop each kidney and there are 2 diff. hormone categories (medulla and cortex)
adrenal medulla secretes ____ in response to ….
secretes epinephrine and norepinephrine in response to sympathetic stimulation (fight/flight) by neuron stimulation
adrenal cortex produces 3 major groups of steroids
- mineralocorticoids
- glucocorticoids
- gonadocorticoids
the 3 major groups of steroids the cortex produces are collectively called
corticosteroids
what do mineralocorticoids do + an example of it
regulates electrolytes and water balance such as aldosterone (goes hand in hand with ADH)
what do glucocorticoids do + an example of it
increase blood glucose levels to adapt to stress such as cortisol
what do gonadocorticoids do + an example of it
release androgens: male sex hormones to produce testosterone
and
release estrogen: female sex hormones
how does aldosterone and ADH go hand in hand?
in the kidneys, aldosterone holds up Na+ and ADH holds on to pee whenever blood pressure/ volume is low
- wherever water goes salt/Na+ follows..
adrenal medulla is the ____ and adrenal cortex is the ___
inside and cortex is outside
where are parathyroid glands located and what do they secrete
posterior surface of thyroid glands and secretes parathyroid hormone (PTH)
when do the parathyroid glands secrete PTH
in response to low blood calcium levels (hypocalcemia)
-so it increases blood calcium levels
how does PTH help blood Ca2+ levels go back to normal from being low?
mobilizes calcium from bone and increases Ca2+ absorption at small intestine + reabsorption at kidneys
PTH exerts its effects in 3 areas…
kidneys, bone, small intestine (digestive tract)
where is the thyroid gland located at
bi-lobed gland located on anterior surface of trachea, inferior to thyroid cartilage
thyroid gland secretes _____ in response to ___
secretes TH (thyroid hormone) in response to TSH from the pituitary gland and calcitonin
what is TH (thyroid hormone) made of and what does it control
T3 (tri-iodothyronine)
and T4 (thyroxin)
controls rate of body metabolism and cellular oxidation
increase metabolism means you have more _____
more energy
what does calcitonin do
decreases blood calcium levels by stimulating calcium deposition in bone
(TH disorder) what is goiter caused by?
dietary iodine deficiency (in underdeveloped countries mainly)
(TH disorder) Graves disease causes
hyperthyroidism
- bulging eyes
thyroid hormones effect on peripheral tissue
- increase O2 rate consumptions and energy consumption = leads to increase body temp.
- increase heart rate and force of contraction = leads to rise in blood pressure
-stimulation of RBC formation = enhancing O2 delivery
- increase sensivity to sympathetic stimulation
- maintains normal respiratory centers if there are changes in O2 and CO2 concentrations
relationship between hypothalamus, anterior pituitary gland, and thyroid gland
hypothalamus releases TRH (thyroidtropin release. h.) to anterior p.g, then that produces/releases TSH (thyroid stimulating h.), TSH targest thyroid gland to released T3 and T4 to the body
name the hormones from the anterior pituitary gland and their function
- GH (growth hormone)
goes everywhere (liver, muscle, bone, cartilage etc.
stimulates body/somatic growth - TSH (thyroid stimulating hormone)
goes to thyroid gland
speeds up metabolism. stimulates thyroid gland to release thyroid hormones - ACTH (adrenocorticoidtropic hormone)
goes to the adrenal cortex + tells it to released its corticoid steroid hormones - FSH (follicle stimulating h.)
go to the ovaries + testes
females: stimulates ovarian follicle maturation + estrogen production
males: stimulates sperm production
- LH (luteinzing h.)
go to the ovaries + testes
females : triggers ovulation and stimulates ovarian production of estrogen + progesterone
males: promotes testosterone production
- PRL (prolactin)
goes to breast tissue
promotes lactation
what exerts highest level of endocrine control and where is it located
the hypothalamus and its contained within the floor and wall of 3rd ventricle
- exerts both direct and indirect control over activites of many diff. endocrine organs
- integrates nervous and endocrine system activity
many of the hypothalamus function is carried out by the ____
pituitary gland
adenohypophysis
anterior pituitary gland
neuorhypophysis
posterior pituitary gland
describe hypothalamic control over anterior pit. gland
it secretes 2 specific regulatory hormones that control production of hormones in ant. pit. gland
what system transports regulatory hormones to anterior pituitary
hypophyseal portal system and this is how ant. pit gland is linked to the hypothalamus by
the 2 hypothalamic regulatory hormones
- releasing hormones (RH)
- inhibiting hormones (IH)
describe hypothalamic control over posterior pit. gland
hypothalamic neurons synthesize ADH and oxytocin and it is only stored and released in/from the posterior pit. gland
does the posterior pituitary gland synthesize ADH/Oxytcin?
NOPE only stores and released them
hypophysis
pituitary gland
where is the pituitary gland located?
sella turcica of sphenoid bone
tropic hormones are
hormones released from anterior lobe
how many classes of hormones are there chemically
2!
1. amino acid based (protein hormones)
2. steroids (lipid based)
describe amino acid based hormones
these protein hormones make up most hormones
- amino acid derivatives and peptide hormones
- almost all are water soluble except thyroid hormones
- act by using 2nd messengers
- rapid and short lasting effects
describe steroid hormones
these are lipid based (fat)
- synthesized from cholesterol
-lipid derivatives along with eicosanoids
- released by reproductive organs
-remain in circulation longer - these are only gonadal and adrenocortical hormones
- lipid soluble and can easily pass through the plasma membrane of target cell and bind to receptors inside cells
examples of steroid hormones
androgens (by testes) (testosterone)
estrogen + progestins by ovaries
examples of amino acid based hormones
epinephrine + norepinephrine
insulin
oxytocin
GH
ADH
melatonin
thyroxine
where are hormone receptors located?
inside cell or on the plasma membrane
3 ways hormones bind to receptors in target cells
- amino acid based h. are water soluble hormones (except TH) so when they reach the plasma membrane, protein receptor activates G protein which then increase cAMP production then cAMP acts as a 2nd messengers and opens ion channels and activated enzymes. ORRRRRRR they use Ca2+ as a 2nd messenger in combination with calmodulin
- lipid soluble hormones (steroids and TH) can just diffuse through the membrane and bind to cytoplasmic/ nuclear receptors then bind to hormone receptor complex to DNA then theres gene activation and transcription/mRNA production then translation / protein synthesis. then the target cell response
- Thyroid hormone can get across the cell membrane and binds to receptors at mitochondria and nucleus, linreasing ATP production the theres target cell response along with whatever went on ^^^ (no. 2)
common second messengers
cAMP and Ca2+
