Homeostasis

Investigating

Homeostasis

Nutrition Standard 1: Plan and conduct an investigation to

provide evidence that feedback mechanisms maintain

homeostasis.

What is Homeostasis?

Homeostasis is the maintenance and regulation of the internal environment within the body.

The body is not maintaining a constant environment but rather a narrow range of conditions

The body is organized so that it has many controls in place to maintain a healthy environment

Homeostasis SongFrom: http://www.youtube.com/watch?v=1iPndNB7mjw

Levels of organization

1. Cells – Each type is specialized to perform specific functions.

2. Tissues – Groups of similar cells that work together.

3. Organs – Groups of different tissues working together.

4. Organ Systems – Different organs working together.

5. Organism – Organ systems working together to maintain life.

Feedback Mechanisms

Negative Feedback Loop

Negative feedback mechanisms counteract or reverse changes within the body if conditions move above or below the narrow range of conditions

Very Common in the body

Positive feedback Loop

Positive feedback loops increase the rate of change away from the normal range

Not very common in the body

Negative feedback: Body Temperature

Positive Feedback: Oxytocin Production during labor

What happens when you exercise?

Heart Rate?Temperature?Breathing?Anything else?

Disruptions in Homeostasis

What happens when you get a virus?

These are short term effects that

generally have no lasting impact

Long Term Effects

Long term disruption of homeostasis can cause lasting damage.

Example: Diabetes

If the body fails to regulate blood glucose levels properly it can affect the entire body Kidneys excrete excess glucose and water Fat used as energy causes increased blood acidity Normal cellular function is compromised

throughout the body