Question

1.6 The human body contains numerous feedback control loops that are essential for regulating key physiological variables. For example, body temperature in a healthy person must be closely regulated within a narrow range. 1. Briefly describe one or more ways in which body temperature is regulated by the body using feedback control. 2. Briefly describe a feedback control system for the regulation of another important physiological variable.

Answer 1

Body temperature is regulated by negative feedback.

1.

The stimulus is when the body temperature exceeds 37 degrees Celsius,

the sensors are the nerve cells with endings in the skin and brain,

the control is the temperature regulatory center in the brain, and the effector is the sweat glands throughout the body.

2.

Another important physiological variable.example of feedback is the control of blood sugar.

1. After a meal, the small intestine absorbs glucose from digested food. Blood glucose levels rise.
2. Increased blood glucose levels stimulate beta cells in the pancreas to produce insulin.
3. Insulin triggers liver, muscle, and fat tissue cells to absorb glucose, where it is stored. As glucose is absorbed, blood glucose levels fall.
4. Once glucose levels drop below a threshold, there is no longer a sufficient stimulus for insulin release, and the beta cells stop releasing insulin.