1. Introduction to Homeostasis

2. Class Discussion What do you notice happening to your body when:
You’re not feeling well
Running a temperature
Shivering
Sweating
Being thirsty

3. Reading
Read the article: A degree of luck: How did a 13-month-old baby come back to life after being “frozen solid”?
Record the key changes that happen due to lower body temperature
Provide an indication as to whether these changes are potentially positive or negative or both
Positive: lower heart rate, lower oxygen requirements, reduced enzyme activities
Negative: blood clotting, kidneys work overtime, hallucinations

4. Maintaining Homeostasis
What are 2 ways in which the body regulates its respiratory gases during exercise?
1. Increasing breathing rate
2. Increasing heart rate

5. Immune system produces antibodies
Describe two mechanisms that operate to restore homeostasis after infection by a pathogen:
Immune system produces antibodies
Fever
Pathogen: An agent causing disease or illness to its host
Getting a fever is a good thing. A fever is our bodies natural response to fighting germs
Increase production of WBC
Inflammation at the site of infection

6. Describe 2 mechanisms by which responses to stimuli are brought about and coordinated:
Hormonal response: release of adrenaline
Nervous response: reflexes = withdrawal from pain

7. Reading Read: Homeostasis
Together we will go through the “Negative Feedback Mechanism”