Question

Which of the following describes a negative feedback loop?

When the heart rate is too high, the body sends hormones that continually increase the heart rate higher.
When a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones.
When blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows.
When a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs

Answer 1

The statement - When blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows, describes a negative feedback loop.

Step-by-step explanation:

In the human body, the term homeostasis means the tendency of the various systems in the human body to stay in optimal ranges for health by self regulation through feedback controls. It is very important because it maintains equilibrium and provides stability to the human body. A negative feedback loop (inhibitory loop) is a type of self-regulating system in which increased output from the system inhibits the future production by the system. Example of negative feedback to achieve homeostasis are blood pressure , body temperature, blood sugar. In blood sugar regulation, the hormone insulin lowers blood glucose when levels are high and the glucagon increases blood glucose when levels are low. In a positive feedback system, the output amplifies the original stimulus. Examples of a positive feedback system are child birth, lactation, blood clotting etc. During child birth, the hormone oxytocin released increases and speeds up the contractions.