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;
14 Cards in this Set
- Front
- Back
|
What are Hormones
|
Hormones are chemical messengers that produce effects by modifying the action of a target cell
|
|
|
Where are steroid hormones derived from?
|
Cholestrol
|
|
|
Whats special about peptide hormones?
|
They are chains of amino acids that are water soluble
|
|
|
Prostaglandis
|
derived from fatty acid and usually function as local hormones
|
|
|
How Steroid Hormones Work
|
1. Produced by endocrine glands and released into bloodstream.
2. lipid soluble, easily cross plasma membrane 3. inside target cells, move to nucleus and combiune with receptors 4.mRNA directs synthesis of proteins that alter activity of target cells |
|
|
The responsiveness of a target cell depends on...?
|
the number of receptors, consentration of hormone and influences exerted by other hormones
|
|
|
Permissive Interaction and ex.
|
Hormone 1 acts on target, allowes hormone 2 to act on target
ex. milk under control of prolactin |
|
|
Synergetic Interaction and ex.
|
Hormone 1 & 2 act on same target, greater than either hormone alone
ex. prolactin and testosterone can work together in brest cancer cells |
|
|
Antagonistic Interaction and ex.
|
Hormone 1 has opposite affects as hormone 2
ex. endometrial growth of uterus is stimulated bty estrogen but inhibited by progesterone |
|
|
Negative Feedback
|
1. A hormone is released from the gland
2. blood levels of the hormone begin to rise and trigger a response from target 3.The response of the target inhibits further production and release of the hormone 4. hormone levels decrease and the target is less responsive |
|
|
2 ways other than + - feedback that hormones are released
|
endocrine glands secrete hormones in response to nerves, and hypothalamus
|
|
|
Positive feed back
|
1. a hormone is relesed from enocrine gland
2.blood levels rise and trigger response 3.the response by the target increases produiction and releases hormone 4. Hormone levels increase and target is more responsive |
|
|
Hormonal Control of Puberty
|
1.Hypothalamus releases GNRHP
2.Pituatary- folicle stimulating hormone 3. Lutenizing hormone travels from pituatary to the gonads |
|
|
Low levels of testosterone=
|
more GnRH and more gonadotropic
|
