endocrine system Flashcards
what are the functions of the endocrine system
- growth and development
- metabolism
- fluid composition and volume of ECF
- environmental changes
- controls all aspects of reproduction
what are the components of the endocrine system
hormone, gland, target cell
what is a hormone
chemical signal that travels through blood stream to a target cells and alters target cell activities
what is a gland
group of cells that synthesize and secrete hormones
what is a target cell
cell with specific receptors for that hormone
compare the endocrine system to the NS: what signals do they use?
end: chemical signal
NS: chemical and electrical signals
compare the endocrine system to the NS: how is they target reached
end: reached by blood stream
NS: target cell is right beside
compare the endocrine system to the NS: their reaction time and how long their affects last
end: slow to react, long lasting
NS: fast to react, short in duration
compare the endocrine system to the NS: what are they involved in
end: growth, development, reproduction, metabolism, etc
NS: movement, crisis management
what are some chemical signals that coordinate cell activities
neural synapse
gap junctions
autocrine and paracrine
hormones
how does the neural synapse coordinate cell activities
they release NT that alters adjacent cells
how do gap junctions coordinate cell activities
- they allow ion movements between cells
- ensure that cells contract as a unit
how does paracrine and autocrine coordinate cell activities
- they’re local chemical signals between same or adjacent cells
- they don’t circulate
how do hormones coordinate cell activities
travel through bloodstream to target cells, which coordinates organs and systems
how does the binding of a hormone to a receptor alter cell activity
they alter cell activity by altering a protein
ex. enzyme, regulatory factors, membrane channels
what are 3 different stimuli that stimulate hormone secretion
- change in a chemical
- NS (adrenal medulla)
- another hormone
which gland has a duct: endocrine gland or exocrine gland?
exocrine gland
how are binded hormones inactivated
by enzymes, binding or removal of kidneys or liver
how are hormones classified
water soluble or fat soluble
how are hormones classified as water soluble? give some examples
- they’re protein derived
- amino acid derived or polypeptide derived
give some examples of lipid proteins
glycoproteins
steroids
eicosanoid
what’s the difference in the way water soluble vs lipid soluble act on a cell
water: acts through second messenger signalling cascade outside of cell
lipid: acts by binding to intracellular receptor inside cell
what type of hormone uses the second messenger signalling system
water soluble
what is a G protein
- membrane bound protein
- activated by hormone-receptor complex
- activated adenylate cyclase
what is adenyl cyclase
- enzyme that synthesis cyclic AMP from atp
what is cyclic AMP
- the second messenger
- formed in cytoplasm of target cell
describe the steps in the second messenger signalling
- hormone binds to cell surface receptor and creates a hormone-receptor complex
- complex activated G protein
- G protein activate adenylate cyclase
- adenylate cyclase form cyclic AMP from ATP
- cAMP acts as second messenger and activates the protein kinases
- it then phosphorylates which results in turning on/off a protein or membrane channel
what are the steps in hormone signalling
- a steroid hormone binds to a receptor thats either in the cytoplasm or in the nucleus of the target cell
- hormone-receptor complex turn on/off transcription
what is a cascade
a series that is a chain of linked enzyme catalyzed reactions
what is a down and up regulation
inhibition or stimulation of receptor formation
what is the role of the anterior portion of the pituitary gland
- glandular
- creates/contains cell population that secrete 8 tropic hormones
what is the role of the posterior poriton of the pituitary gland
- neural
- contains axons and synaptic knobs that secrete ADH and oxytocin
what are the 7 hormones that the anterior pituitary gland releases
- ACTH
- TSH
- GH
- PRL
- FSH
- LH
- MSH
what is the role of ACTH
adrenocorticotropic hormones
- stimulates the production of cortisol
what is the role of TSH
thyroid stimulating hormone
what is the role of MSH
- melanocyte stimulating hormones
(pigment called melanin)
what is the role of FSH
- follicle stimulating hormone
- sperm and egg formation
what is the role of LH
- luitenizing hormone
- responsible for hormone production
- aids in maturation of cells of ovaries and testis
what is the role of PRL
- prolactin
- causes breasts to grow and milk to be produced during pregnancy
what is the role of GH
- growth hormone that stimulates protein synthesis in cells like bones and muscle
how is the hypothalamus related to the anterior pituitary gland
- regulatory factors are released from the hypothalamus are released into the hypophyseal portal system
- this system gives hypothalamus direct control/connection to the anterior pit gland
how is the hypothalamus and the posterior pituitary gland related
- it’s an extension of the hypothalamus neuron
- has a separate circulation
how does the hypothalamus regulate the endocrine system
- secretes regulatory factors that act on the pituitary gland
- posterior pituitary releases from axon terminal ADH and oxytocin into the blood stream
- neural pathways control sympathetic output of adrenal medulla
what is the role of the thyroid gland
synthesizes and secrets 2 hormones
- thyroid hormone
- calcitonin
what is the function of the thyroid hormone
- acts on almost all cells
- important for growth ad development
- increases metabolism (as if you’re turning a furnace on high)
how is the thyroid hormone regulated
by a negative feedback loop
describe the negative feedback loop that controls thyroid hormone
stim: dec in temp
resp: inc in temp
path: hypothalamus - TRH - anterior pituitary - TSH - thyroid and thyroid hormone - all cells
inc in thyroid hormone inhibits what?
TSH secretion
inc in temp inhibits what
stops the regulatory factors that release TRH from hypothalamus
what is the role of the pineal gland
- synthesizes melatonin
what is the adrenal gland
synthesizes mineralocorticoids, glucocorticoids, androgens
what is the role of mineralocorticoids
aldosterone
- inc blood pressure and volume
what is the role of glucocorticoids
- cortisol
- long term stress
what is androgens
testosterone
what is the role of the adrenal medulla
- secretes epinephrine and norepinephrine
- parts of the sympathetic response
describe the role of cortisol
- long term stress hormone
- provides energy by mobilizing energy reserves
- is an anti-inflammatory that suppresses the immune system
what is the role of epinephrine and norepinephrine
- inc HR and BP
- provides energy
what is the pancreas
an exocrine and endocrine gland
what hormones do the pancreas secrete
- insulin
- glucagon
what is the role of insulin
- reduces blood sugar levels by using and storing glucose
what is the role of glucagon
- inc blood glucose levels by mobilizing energy reserves
when does diabetes occur
- when glucose is not utilized
- instead fat are mobilized
what is diabetes 1
inadequate insulin production
what is diabetes 2
insulin levels are normal or high but tissues fail to respond to it
what is the secondary endocrine function of the kidneys
- release AgII and EPO
what is the secondary endocrine function of the heart
release ANP
what is the role of ANP
- decreases BP and volume
what is the role of Ag II
inc BP and volume
- vacoconstricts
what is the role of oxytocin
labor contraction
lactation
sexual response
what are antagonistic hormones and give an example
- opposing
- insulin and glucagon
what are synergistic hormones and give an example
- additive
- growth hormones and glucocorticoids
what are permissive hormones and give and example
- one hormone is needed for function of second hormone
- epinephrine and thyroid hormones
what is an integrative hormone and give an example
- different but complimentary effects
- calcitriol and parathyroid hormone
what is the alarm phase of stress
short term phase
flight or fight
what hormone is released during the alarm phase
epinephrine by the SNS
what is the resistance stress phase
- chronic or long term
what hormone is releases during the resistance stress phase
cortisol, aldosterone, ADH, glucagon, epinephrine
- to maintain BP and mobilize energy reserves
what is the exhaustion phase of the stress phase
- electrolytes, imbalance, exhausted reserves,
- inhibition of immune system causes organ damage and failure
