Is the clotting of blood an example of positive or negative feedback?
Positive Feedback--It reinforces the stimuli
Negative feedback.
Positive
Aldosterone is both responsible for absorption of sodium and excretion of potassium. If it is regulated by the level of potassium in blood, then we have negative feedback as high levels of aldosterone causes a decrease in potassium level in blood. If it is regulated by the level of sodium in blood, the story is just the opposite and we have positive feedback. -my own conclusion from several researches-
positive
negative feedback via baroreceptors in the carotid artery and aortic arch
Control of blood pressure.
It depends on whether it is positive or negative feedback. Most biological organisms exhibit both negative and positive feedback, including humans. An example of positive feedback is contractions during childbirth. Negative feedback is blood sugar regulation based upon the release of insulin into the bloodstream at necessary times.
If high blood pressure is at play then a negative feedback system would reverse this. Through this negative feedback the stimulus of increased pressure is reversed or decreased by decreasing heart rate which decreases the blood pressure. If low blood pressure is at play the negative feedback system would also be appropriate because your body needs to reverse this stimulus. Your heart rate would increase to increase blood pressure. NOTE: Positive Feedback system enhances or further intensifies the stimulus so we would not want that for blood pressure. This is seen for birth contractions. You want to intensify contractions to enable the baby to get out of the canal. However, usually you need some external event to turn off the positive feedback or it could be fatal. In this case the baby is born so that stops the contractions.
Negative feedback mechanisms
It depends on whether it is positive or negative feedback. Most biological organisms exhibit both negative and positive feedback, including humans. An example of positive feedback is contractions during childbirth. Negative feedback is blood sugar regulation based upon the release of insulin into the bloodstream at necessary times.
Perhaps you don't understand the meaning of positive and negative feedback. Positive feedback keeps adding to a process. Negative feedback doesn't. If a person fills a bathtub, positive feedback will continue the filling even if it runs over. Negative feedback will turn the water off when the tub is filled. So, negative feedback maintains homeostasis. Homeostasis means "steady state". When a processes is completed, it turns it off. Example: Blood sugar levels remain in a certain range.
Its a negative feedback,because the smaller the lumen , the higher the blood pressure because of the deposit in the vessel thus causing the resistance.
Postive feedback
This process is called negative feedback. There are only two that are positive: childbirth and blood clotting. Negative feedback keeps things in balance.