Homeostasis and its Role in Physiology

Definition of Homeostasis

• Homeostasis is the process by which the brain and body maintain stability in the internal environment.
• It regulates temperature, heartbeat, metabolism, etc., despite changes in external conditions.

Examples of Homeostasis

• Exercise:
  • When exercising, you become out of breath and hot.
  • Post-exercise, the body cools down and lowers heart rate to return to normal.
• Drug Use:
  • Example: Amphetamines raise heart rate, but the body attempts to lower it back to normal.

Homeostasis and Drug Use

Ritualistic Behaviors

• Regular drug users develop ritualistic behaviors linked to drug intake.
• Examples include taking drugs in a specific location, at a particular time of day.

Brain's Anticipatory Response

• The brain recognizes external cues indicating imminent drug intake.
• It preemptively adjusts functions such as lowering heart rate before drug use.

Tolerance Development

• Over time, due to pre-adjustment, a higher drug dose is needed to achieve the same effect.

Scenarios Explaining Homeostasis in Drug Use

Scenario 1: Cue Without Drug

• Body pre-adjusts for the drug but receives none.
• Results in a crash due to lack of counteractive drug effects.

Scenario 2: Drug in a New Environment

• In a new environment, the body doesn’t pre-adjust.
• Taking the usual high dose can lead to overdose as the body is unprepared.
• This lack of anticipation can result in the body being overwhelmed by the drug.

Conclusion

• Understanding homeostasis and how the body anticipates changes can explain physiological responses during drug use and the risks of overdose.