Introduction to Homeostasis

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

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

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

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

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

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