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
