What is the endocrine system?

1. What is the endocrine system? The endocrine system is a complex collection of hormone-producing glands that control basic body functions such as metabolism, mood, growth and sexual development.

2. How does the Endocrine System Regulate the Body? It is made of glands that secrete hormones directly into your bloodstream These hormones cause changes in your body

3. What is a hormone and what do they do? • A hormone is a “chemical messenger” • A chemical that delivers a message • Hormones are made in the glands of your endocrine system and secreted into your blood • They travel through your blood until they reach specialtarget cells

4. Examples of Hormones

5. Fight or Flight Response Controlled by an area of the brain called the hypothalamus: the part of the brain that links the nervous and endocrine systems.

6. Fight or Flight Response When we think we are in danger, the hypothalamus begins a series of nerve cell firings and releases hormones like adrenaline, into our bloodstream. These patterns of nerve cell firing and chemical release cause our body to undergo a series of very dramatic changes.

7. These changes are designed to either help you fight or run away (flight) to safety in times of danger

8. Stimulus/Response • Stimulus: any change in an organism’s environment that causes to the organism to react. It is a fancy way of saying “cause”. • Response: how the organism reacts to a stimulus and results in a change in behavior. It is a fancy way of saying “effect”.

9. Stimulus : Response Response = Hypothalamus releases hormones into body Response = Heart rate and breathing rate increase, sweating increases, blood thickens, blood flow to muscles increase all so we can RUN! Bear = external stimulus Hormones become = Internal stimulus

10. Stimulus/Response Examples Stimulus – You are hot. Response – You sweat. Stimulus – Your body needs fuel. Response – Your stomach growls and churns. Stimulus - Bright light Response – Closed pupils