Biology Forums - Study Force

Science-Related Homework Help High School Level Science Topic started by: mikelobco on Aug 27, 2012



Title: Oxytocin is different from most hormones because its effects are due to positive feedback loops?
Post by: mikelobco on Aug 27, 2012
true or false? why


Title: Oxytocin is different from most hormones because its effects are due to positive feedback loops?
Post by: rjedlicka on Aug 27, 2012
True.  When too much pressure is applied to the cervix during childbirth, oxytocin is released and stimulates uterine contractions, which causes more oxytocin to be produced, and so on until the child is delivered.  This is called the Ferguson reflex.


Title: Oxytocin is different from most hormones because its effects are due to positive feedback loops?
Post by: mikejuies on Aug 27, 2012
Positive feed back in this case is neuronal, not hormonal. Prolactin also acts similarly.


Title: Oxytocin is different from most hormones because its effects are due to positive feedback loops?
Post by: rjcool123 on Aug 27, 2012
True. Most hormones are released to stimulate endocrine glands when the level of their particular hormone drops in the blood plasma. Oxytocin is released in several cases: it responds to dilation of the cervix during childbirth to stimulate uterine contractions; it also stimulates mammary glands to release milk in response to a suckling infant, which is called "milk let-down reflex". Oxytocin levels during pregnancy also increase maternal instincts to love and protect the fetus and new-born infant. All of these are positive feedback loops; wider cervix=more oxytocin; suckling infant=more oxytocin and more milk; pregnancy and delivery=more oxytocin to accentuate maternal feelings.
There is even evidence that oxytocin increases in response to physical nearness of lover, husband..in other words, it helps women 'get in the mood', but this is still being researched. This would definitely be a feedback loop, though!