Term
True or False
GnRH peptides are present in only a select few vertebrates |
|
Definition
False
present in all vertebrates |
|
|
Term
| How many types of GnRH are there? |
|
Definition
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Term
| Describe the release, circulation and action of GnRH |
|
Definition
-released in a pulsatile manner in the median eminence
-travel via portal system to ant. pituitay
-GnRH neurons in hypothalamus receive info about internal/external status |
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Term
| Describe the action of GnRH receptors |
|
Definition
-G protein coupled receptors
-GnRH binding can stimulate G-alpha-q & G-alpha-s
-leads to synthesis & release of LH & FSH (gonadotropins) |
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Term
True or False
There are different types of pituitary cells for the production of LH vs FSH |
|
Definition
False
In most mammals the same gonatoropic cells produce both FSH & LH |
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Term
| Describe the structure & function of LH & FSH |
|
Definition
-composed of an alpha subunit (common among hormones) & beta subunit (unique for each hormone)
-beta subunit is the limiting factor
-control gene transcription
-stored in vesicles until GnRH release signal is received |
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Term
| What causes the release of LH vs FSH when a GnRH signal is receivedere is in the pituitary |
|
Definition
| -the pulse frequency of GnRH |
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Term
| What is the role of LH & FSH receptors? |
|
Definition
-G protein coupled receptor which activates G-alpha-s
-increases cAMP |
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Term
| Where is Inhibin produced? |
|
Definition
Sertoli cells (males)
Granulosa cells (females) |
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|
Term
| What are the roles of inhibin & activin? |
|
Definition
Inhibin: inhibits FSH
Activin: stimulate FSH |
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|
Term
| Where is activin produced? |
|
Definition
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Term
| What hormones act in conjunction with GnRH? |
|
Definition
|
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Term
| What is the original molecule used to produce gonadal steroids? What determines which type of steroid will be produced? |
|
Definition
cholesterol
-determined by the enzyme substrate present in the cell |
|
|
Term
| What distinguishes estradiol-17B from testosterone? |
|
Definition
| the presence of a phenolic A ring |
|
|
Term
| Which is more effective, estradiol-17B, testosterone or progesterone? |
|
Definition
|
|
Term
| What type of receptors do sex steroids use? |
|
Definition
| nuclear hormone receptors |
|
|
Term
| How do estrogen receptors work? |
|
Definition
Two receptor types (ER alpha & ER beta)
require co-activators to mediate their effects on the target gene
-alpha receptor stimuates transcription while beta receptor inhibits it |
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Term
| What type of receptor is used by LSH & FSH |
|
Definition
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