Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
76 Cards in this Set
- Front
- Back
|
Hormones from the Neural Posterior Lobe of the Pituitary
= Neurohypophysis = Pars Nervosa --- and --- |
Vasopressin;Oxytocin
|
|
|
Hormones from the Neural Posterior Lobe of the Pituitary
= ---- = --- Vasopressin and Oxytocin |
Neurohypophysis ; Pars Nervosa
|
|
|
Vasopressin and Oxytocin
Produced in the --- of the Hypothalamus Released following an action potential in the neurosecretory cells that produced them |
Supraoptic Nucleus and Paraventricular Nucleus
|
|
|
Vasopressin and Oxytocin
Produced in the Supraoptic Nucleus and Paraventricular Nucleus of the --- Released following --- |
Hypothalamus;an action potential in the neurosecretory cells that produced them
|
|
|
Vasopressin and Oxytocin
Structure: Are --- = 9 aa’s long Have 1 ---bond - is required for activity Produces 6 aa ring with 3 aa “tail” Exist as a family of molecules 3 are vasopressins: Vaso ------; Pressin - ---- Arg - vasopressin: arg @ 8 pos. Lys - vasopressin: lys @ 8 pos. 4 - ser - lys - vasopressin |
nonapeptides;disulfide ; circulation;pressure
|
|
|
Vasopressin and Oxytocin
Structure: Are nonapeptides = 9 aa’s long Have 1 disulfide bond - is required for activity Produces 6 aa ring with 3 aa “tail” Exist as a family of molecules 3 are vasopressins: Vaso - circulation; Pressin - pressure ---- |
Arg - vasopressin: arg @ 8 pos.
Lys - vasopressin: lys @ 8 pos. 4 - ser - lys - vasopressin |
|
|
Vasopressin and Oxytocin
Structure: |
Are nonapeptides = 9 aa’s long
Have 1 disulfide bond - is required for activity Produces 6 aa ring with 3 aa “tail” Exist as a family of molecules 3 are vasopressins: Vaso - circulation; Pressin - pressure Arg - vasopressin: arg @ 8 pos. Lys - vasopressin: lys @ 8 pos. 4 - ser - lys - vasopressin |
|
|
Vasopressin and Oxytocin
Precursor peptide is produced via protein synthetic pathway: |
Transcription Translation
DNA ---->mRNA ------>Protein |
|
|
Vasopressin and Oxytocin
Product of translation is a --- |
precursor:
“Preprohormone” Is larger Gets cleaved |
|
|
Vasopressin and Oxytocin
Product of initial cleavage is a --- |
“Prohormone”
|
|
|
Vasopressin and Oxytocin
Product of initial cleavage is a “Prohormone” is subject to additional processing which may include: |
Folding
Formation of disulfide bonds Additional cleavage Modification of amino acid residues |
|
|
Vasopressin and Oxytocin
General path during precursor processing: |
RER Golgi Secretory granules
|
|
|
Vasopressin and Oxytocin
Final cleavage and processing in the --- Occurs as the --- travels down axon to terminal --- contains the hormone and a larger peptide cleavage product, neurophysin |
secretory granule;granule;Granule
|
|
|
Vasopressin and Oxytocin
Final cleavage and processing in the secretory granule Occurs as the granule travels down axon to --- Granule contains --- |
terminal;the hormone and a larger peptide cleavage product, neurophysin
|
|
|
Vasopressin and Oxytocin
--- in the secretory granule |
Final cleavage and processing
|
|
|
Vasopressin and Oxytocin
Neurophysin is thought to have function, exact role unknown: |
carrier?
stabilizer? |
|
|
Vasopressin and Oxytocin
---is thought to have function, exact role unknown: carrier? stabilizer? |
Neurophysin
|
|
|
Vasopressin and Oxytocin
Following secretion, the half-life of the hormone is on the order of --- |
minutes
|
|
|
A family of --- exists:
Some are characteristic of particular vertebrates |
Nonapeptides
|
|
|
A family of Nonapeptides exists:
Some are characteristic of particular --- |
vertebrates
|
|
|
Vasopressin
Function: Vasopressin Is --- |
antidiuretic hormone (ADH)
|
|
|
Vasopressin
Function: Vasopressin Is antidiuretic hormone (ADH) Diuresis: Dia = ---, ouresis = --- Antidiuresis Antidiuretic: stops, slows urine production |
through;urine
|
|
|
Antidiuretic:
|
stops, slows urine production
|
|
|
Vasopressin
Most of the antidiuretic hormone activity is associated with the vasopressins: |
Arg - vasopressin
Lys - vasopressin 4-ser-lys - vasopressin |
|
|
There is also a ---
= half of one, and half of other has intermediate effects |
vasotocin
|
|
|
There is also a vasotocin
= |
half of one, and half of other
has intermediate effects |
|
|
Vasopressin
Q: What is ADH? Precisely: The total antidiuretic activity = |
total vasopressins
= all forms present; must specify all |
|
|
Vasopressin, Mechanism of Action
Target: |
Collecting duct, Nephron, Kidney
|
|
|
What targets Collecting duct, Nephron, Kidney?
|
Vasopressin
|
|
|
Vasopressin, Mechanism of Action
Causes insertion of water channels into --- Affects the permeability of --- More water exits duct, reenters tissue Result: Kidney retains more water; urine more concentrated, reduced in volume |
apical cell membrane, collecting duct;collecting duct cells
|
|
|
Vasopressin, Mechanism of Action
Causes insertion of water channels into apical cell membrane, collecting duct Affects the permeability of collecting duct cells More water exits duct, reenters tissue Result: --- |
Kidney retains more water; urine more concentrated, reduced in volume
|
|
|
Vasopressin, Mechanism of Action?
|
Causes insertion of water channels into apical cell membrane, collecting duct
Affects the permeability of collecting duct cells More water exits duct, reenters tissue Result: Kidney retains more water; urine more concentrated, reduced in volume |
|
|
Vasopressin, Mechanism of Action
Human without ADH: Produces --- of urine per day Compare: Desert species: Kangaroo Rat which produces --- of ADH per day Non-desert species: Dog which produces ---of ADH per day Kangaroo rat urine is -- more conc. than that of dog |
4-12 liters;50mU;6mU ;6x
|
|
|
Vasopressin, Mechanism of Action
Osmolarity is --- |
a measure of total solute concentration
|
|
|
a measure of total solute concentration
|
Osmolarity
|
|
|
Vasopressin, Mechanism of Action
Vasopressin works by: |
Increasing the permeability of the epithelial barrier:
Enabling water movement due to preexisting osmotic gradient (concentration). |
|
|
Vasopressin, Mechanism of Action
Example: Epithelial barrier Functional unit of kidney is the nephron Nephron tubule composed of epithelial cells Epithelial cells have special cell-cell junctions, including Tight Junctions Tight Junctions control -- |
the permeability of the paracellular path: “Tight” or “Leaky”
|
|
|
Vasopressin, Mechanism of Action
Example: Epithelial barrier Functional unit of kidney is the nephron Nephron tubule composed of epithelial cells Epithelial cells have --- Tight Junctions control the permeability of the paracellular path: “Tight” or “Leaky” |
special cell-cell junctions, including Tight Junctions
|
|
|
Vasopressin controls water permeability in the --- path
|
Transcellular
|
|
|
---, for most substances, requires a membrane channel
|
The transcellular pathway
|
|
|
The transcellular pathway, for most substances, requires a ---
|
membrane channel
|
|
|
Vasopressin, Mechanism of Action
Physiological osmolarity of blood = |
286
|
|
|
Experiment:
1. Establish concentration gradient across membrane 2. Affect permeability of membrane with agent; i.e. +/- vasopressin Result: |
+Vasopressin = 5x rate of untreated
increase in permeability acceleration of water flow |
|
|
Experiment:
Result: +Vasopressin = 5x rate of untreated increase in permeability acceleration of water flow |
1. Establish concentration gradient across membrane
2. Affect permeability of membrane with agent; i.e. +/- vasopressin |
|
|
Vasopressin, Mechanism of Action
Vasopressin causes the insertion of --- into the apical membrane of cells of the collecting duct of the nephron --- constitutes the principal water channel in the brain |
Aquaporin-2 water channels;Aquaporin-4 (AQP4)
|
|
|
Vasopressin, Mechanism of Action
Vasopressin causes the insertion of Aquaporin-2 water channels into the --- Aquaporin-4 (AQP4) constitutes the -- |
apical membrane of cells of the collecting duct of the nephron;principal water channel in the brain
|
|
|
Vasopressin, Mechanism of Action
Aquaporin-1 water channels are present in both --- Vasopressin provides more channels (Aquaporin-2) in the apical membrane of cells in the collecting duct |
apical and basolateral domains of kidney tubule cells;
|
|
|
Vasopressin, Mechanism of Action
--- water channels are present in both apical and basolateral domains of kidney tubule cells Vasopressin provides more channels (Aquaporin-2) in the apical membrane of cells in the collecting duct |
Aquaporin-1
|
|
|
Vasopressin, Mechanism of Action
Aquaporin-1 water channels are present in both apical and basolateral domains of kidney tubule cells Vasopressin provides more channels (Aquaporin-2) in --- |
the apical membrane of cells in the collecting duct
|
|
|
Vasopressin, Mechanism of Action
Vasopressin (ADH): affects permeability of ---; + VP (ADH) increased permeability more water leaves urine, returns to tissue Result: --- |
collecting duct;urine concentration increases
urine volume decreases |
|
|
Vasopressin, Mechanism of Action
Vasopressin (ADH): affects permeability of collecting duct; + VP (ADH) ---- ----- Result: urine concentration increases urine volume decreases |
increased permeability
more water leaves urine, returns to tissue |
|
|
Vasopressin, Mechanism of Action
The vasopressin receptor acts via --- |
adenylate cyclase, cAMP
|
|
|
Vasopressin, Mechanism of Action
The --- acts via adenylate cyclase, cAMP |
vasopressin receptor
|
|
|
Vasopressin, Mechanism of Action
Regulation of vasopressin: Primarily by --- |
input at hypothalamus
|
|
|
Vasopressin, Mechanism of Action
Regulation of vasopressin: Primarily by input at hypothalamus; --- monitor blood osmolarity Also: --- monitor blood pressure Low blood pressure is --- Low blood volume is --- Both increase vasopressin levels |
Osmoreceptor cells;Baroreceptors;hypotension;hypovolemia
|
|
|
Vasopressin, Mechanism of Action
Regulation of vasopressin: Primarily by input at hypothalamus; Osmoreceptor cells monitor ---- Also: Baroreceptors monitor --- --- is hypotension ---is hypovolemia Both increase vasopressin levels |
blood osmolarity;blood pressure ;Low blood pressure ;Low blood volume
|
|
|
Vasopressin, Mechanism of Action
Regulation of vasopressin: Primarily by input at hypothalamus; Osmoreceptor cells monitor blood osmolarity Also: Baroreceptors monitor blood pressure Low blood pressure is hypotension Low blood volume is hypovolemia Both --- vasopressin levels |
increase
|
|
|
Oxytocin
Primary Functions: |
Oxytocic Effect resulting in Partuition (childbirth)
Milk Let Down Reflex during nursing |
|
|
Oxytocin
Oxytocic Effect Is the response of --- Causes smooth muscles in the uterine wall to --- Results in --- |
the pregnant uterus to oxytocin ;contract;the induction of labor
|
|
|
Oxytocic Effect
|
Is the response of the pregnant uterus to oxytocin
Causes smooth muscles in the uterine wall to contract Results in the induction of labor |
|
|
Is the response of the pregnant uterus to oxytocin
Causes smooth muscles in the uterine wall to contract Results in the induction of labor |
Oxytocic Effect
|
|
|
Oxytocin
Milk Let Down Reflex |
Touch receptors in the nipples provide stimulus to the hypothalamus
Posterior pituitary releases oxytocin |
|
|
Oxytocin
Milk Let Down Reflex Touch receptors in the nipples provide stimulus to the -- --- releases oxytocin |
hypothalamus;Posterior pituitary
|
|
|
Touch receptors in the nipples provide stimulus to the hypothalamus
Posterior pituitary releases oxytocin |
Oxytocin
Milk Let Down Reflex |
|
|
Oxytocin
Milk Let Down Reflex Oxytocin acting upon the mammary gland causes the contraction of --- --- are very similar to smooth muscle cells but differentiate from ectoderm (instead of from mesenchyme) |
myoepithelial cells in the walls of lobules (alveoli);Myoepithelial cells
|
|
|
Oxytocin
Milk Let Down Reflex ---causes the contraction of myoepithelial cells in the walls of lobules (alveoli) Myoepithelial cells are very similar to ---but differentiate from --- |
Oxytocin acting upon the mammary gland ;smooth muscle cells ;ectoderm (instead of from mesenchyme)
|
|
|
Oxytocin
Milk Let Down Reflex Oxytocin acting upon the mammary gland causes the contraction of myoepithelial cells in the walls of lobules (alveoli) Myoepithelial cells are very similar to smooth muscle cells but differentiate from ectoderm (instead of from---) |
mesenchyme
|
|
|
Oxytocin
Milk Let Down Reflex contraction ----- |
myoepithelial cells lobules
|
|
|
Vasopressin
Diabetes Insipidus Diabetes = |
to pass through: a large amount of urine
|
|
|
Vasopressin
Diabetes Insipidus Diabetes = to pass through: a large amount of urine Diabetes is a disease of --- |
too little hormone or hormone activity
|
|
|
Vasopressin
Diabetes Insipidus Diabetes = to pass through: a large amount of urine Diabetes is a disease of too little hormone or hormone activity Failure to --- |
produce / transport / secrete / respond to vasopressin
Anything in the pathway |
|
|
Vasopressin
E.G. Brattleboro Rats Have a hypothalamic defect that causes them to have --- |
no circulating vasopressin
|
|
|
Vasopressin
E.G. Brattleboro Rats Have a hypothalamic defect that causes them to have no circulating vasopressin Single nucleotide deletion changes --- Result:---- |
amino acid sequence of preprohormone which is not processed properly;No hormone released
|
|
|
Vasopressin
E.G. Brattleboro Rats Have ---that causes them to have no circulating vasopressin --- changes amino acid sequence of preprohormone which is not processed properly No hormone released |
a hypothalamic defect ;Single nucleotide deletion
|
|
|
Vasopressin
E.G. --- Have a hypothalamic defect that causes them to have no circulating vasopressin Single nucleotide deletion changes amino acid sequence of preprohormone which is not processed properly No hormone released |
Brattleboro Rats
|
|
|
Vasopressin
Brattleboro Rats With no circulating vasopressin: |
Drink 80% of their body weight per day
Excrete 70 % of their body weight per day as urine |
