Test 3: 58 Flashcards
what are the two main systems of control of the body
endocrine→ hormones
neurological
nervous system has a ___ signal path and a __ response time
discrete anatomic pathway
rapidd
endocrine has a __ signal path and a __ response time
dispersed (hormones can go anywhere)
slow (minutes to weeks)
endocrine system regulates
reproduction
growth and development
electrolyte, water and nutrient balance in blood
cellular metabolism and energy balance
immune defenses
endocrine glands
receptors for hormones are either :
extracellular or intracellular
specific ___ interactions will determine how strongly the target cell can respond to any given hormone
hormone receptor
3 ways to increase hormone response
level of hormone in blood
level of receptors on target cell
affinity of hormone-receptor interactions
up regulation of receptors will ___ a cell’s response
increase
amino acid derived hormones ___ pass membranes and require ___ receptors
cannot
extracellular
lipid/steroid hormones have ___ receptors and ___ move through membrane
intracellular
can pass
direct gene action of hormones
lipid- soluble(steroid) hormones can enter the cell and modify genetic activity directly without the need for 2nd messengers
once bound to intracellular receptors, binds to a specific region of DNA
steps of steroid hormone in cell
steroid hormone comes into cell
binds to receptor inside cell forming a receptor-hormone complex
this complex binds to DNA
DNA transcription to mRNA
mRNA made into a protein
protein changes activity within the cell
mechanism of cAMP pathway
hormone binds receptor on outside of cell
receptor binds to G protein
G protein activates adenylate cyclase
adenylate cyclase makes cAMP
cAMP activates protein kinases
protein kinase causes changes inside the cell
what is a hormone that uses cAMP as a second messenger
glucagon
how does cAMP regulates glycogenolysis
glucagon attaches to g protein receptor, which causes release of cAMP→ PKA
PKA will inhibit glycogen synthase (stop storage of glucose)
PKA will activate glycogen phosphorylase (tell cell to breakdown glycogen into usable glucose)
cAMP will help with the storage or breakdown of glucose
the breakdown
glucagon→ cAMP → PKA → breaks down glycogen → releases glucose
how cAMP regulates insulin ____ from pancreas
release
what are some hormones that use the secondary messenger IP3
catacholamines
TRH
ADH
LHRH
ocytocin
how does IP3 act as secondary messenger
amino-derived hormones bind to transmembrane receptor
triggers PIP→ IP3 → EF to release calcium
calcium acts as 3rd messanger
how do diseases cause hormonal signaling goes awry
excess hormones
activated/ down regulated receptors
3 types of endocrine gland stimuli
humoral stimulus (ions in blood will trigger endocrine tissue to release hormones)
neural stimulus (Nervous system will stimulate hormone release)
hormonal stimulus (endocrine tissue talks to other endocrine tissue)
what two hormones are released by the hypothalamus and stored in the pituitary? where in the pituitary?
ADH and oxytocin
posterior pituitary (neurohypophysis)
two parts of the pituitary gland
anterior (adenohypophysis) produces and secretes 6 hormones
posterior (neurohypophysis) stores and secretes 2 hormones
what are the 6 hormones made in the adenohypophysis
TSH
LH/FSH
ACTH
GH
PRL (prolactin)
hypothalamus makes what
ADH
oxytoxin
TRH (Thyrotropin RH)
GnRH (gonadotropin RH)
CRH (corticotropin RH)
GHRH (somatocrinin and somatostatin)??
dopamine
pituitary gland makes what in the anterior pituitary
somatotrophs (GH)
lactotrophs (Prolactin)
thyrotrophs (TSH)
gonadotrophs (LH and FSH)
corticotrophs (POMC→ ACTH, MSH, B-lipotropin and B endorphin)
adenomas
pituitary tumors
pituitary tumors can be __ or __
secretory (prolactinoma, acromegaly, cushing’s)
non secretory
prolactinoma
noncancerous tumor (adenoma) of the pituitary gland in your brain overproduces the hormone prolactin in breast. The major effect is decreased levels of some sex hormones — estrogen in women and testosterone in men.
prolactinoma causes a decrease in levels of what hormones in women and men
women : estrogen
male: testosterone
amenorrhea
absence of menstruation
oligomenorrhea
infrequent menstrual periods (fewer then 6 a year)
galactorrhea
milky discharge from non pregnant females
what are some symptoms of prolactinoma in females
amenorrhea (none or few periods)
galactorrhea (milky discharge)
infertility
what are some symptoms of prolactinoma in males
headaches
visual impairment
reduced sex drive
ED
lack of body and facial hair
treatment for prolactinoma
dopamine agonist therapy
bromocriptine (parlodel)
cabergoline (dostinex)
or
surgery
acromegaly
(giant)
syndrome of bony and soft tissue overgrowth and insulin resistance due to excessive growth hormone (GH) secretion
acromegaly is due to excess of what hormone
growth hormone (GH)
___ therapy is used to treat prolactinoma
dopamine agonist
(dopamine will stop prolactin)
acromegaly is usually caused by ___
pituitary adenoma (98%)
can be from tumors in other parts causing release of growth hormones (breast cancer) or growth hormone releasing hormone (lung cancer)
symptoms of acromegaly
prognathism
macroglossia (really big tounge)
diabetes
teeth issues
ect.
acromegaly can happen in which animals? what are the clinical signs
dogs and cats
more common in male cats
teeth issue, diabetes, weight gain
growth hormone has an indirect action to cause the ___ to release ___
liver and other tissues
insulin like growth factors (IGFs)
causes increase in cartilage and skeletal growth, cell growth and protein synthesis
growth hormone direct effect
(metabolic, anti-insulin)
increased fat breakdown and release
increased blood glucose and other anti-insulin effects
(diabetic)
how to diagnosis acromegaly
serum IGF-1 level
elevated levels
treatment for acromegaly
antagonist to GH-R (pegvisomant)
radiation therapy
surgery to remove part of pituitary
mortality high if not treated (slow progress)
cushing’s disease
serious condition of an excess of the steroid hormone cortisol in the blood level caused by a pituitary tumor secreting adrenocorticotropic hormone (ACTH). ACTH is a hormone produced by the normal pituitary gland.
___ is an excess of the steroid hormone cortisol in the blood level caused by a pituitary tumor secreting adrenocorticotropic hormone (ACTH).
cushing’s
ACTH is a hormone produced by the ___.
pituitary gland
ACTH-secreting pituitary adenomas account for 70% of patients with ___
cushing’s
what is the most common cause of cushing disease
related to medication glucocorticoids also commonly known as steroid or prednisone
how to diagnose cushing’s disease
step 1: establish biochemical proof of cortisol excess
step 2: localize source of hormone excess (pituitary, ectopic or adrenal gland)
hard to diagnose, no good blood test
dexamethasone suppression test
dexamethasone suppression test
The high-dose dexamethasone suppression tests help to distinguish patients with Cushing’s disease (Cushing’s syndrome caused by pituitary hypersecretion of corticotropin [ACTH]) from most patients with the ectopic ACTH syndrome (Cushing’s syndrome caused by nonpituitary ACTH-secreting tumors
cushings happen more in ___
males
