Systems PART 5 Endocrine System RAGING HORMONES Outcomes

Systems PART 5

Endocrine System RAGING HORMONES!

Outcomes �Explain how an organism maintains homeostasis by diagramming feedback loops and describing the role of the endocrine system.

Endocrine System - Another communication system �Endocrine system is “all about the balance…” �HOMEOSTASIS- the ability of the body to maintain a “steady state, ” an internal balance even though the external environment is constantly changing. � EXAMPLE: blood sugar levels– when you eat, glucose levels elevate. Insulin, an endocrine hormone, is produced to bring the levels down. When the glucose level is too low, another hormone, is produced to bring the levels back up. In this way, the glucose levels in our blood are kept in balance.

Comparing the Nervous & Endocrine Systems Endocrine Both • Uses hormones to send messages • Travel through blood stream • Controls things like growth, development, temperature • control body and maintain homeostasis by communicating information to appropriate cells, tissues, organs, and organ systems Nervous • Messages are electrical impulses • Impulses travel along pathways made of neurons • Controls reactions, reflexes

Components of the Endocrine System �Hormones- Chemical signals that are secreted by glands and then transported throughout the body to regulate the activity of other cells. �Glands- The organs that produce and secrete hormones.

How Do Hormones Get Around? �Hormones are transported from the glands where they are produced to their target cells by the blood stream (circulatory system)

Hormone Function �Hormones regulate growth, development, behavior and reproduction �Hormones coordinate the production, use and storage of energy �Hormones maintain homeostasis (temperature, water and salt balance)

Examples of Hormone Action �Hormones can direct a cell to make more of a protein, increase or decrease the rate of an activity or activate a specific enzyme. �Hormones can tell a muscle to relax or tell a cell membrane to alter its permeability.

Regulating the Endocrine System �The Endocrine System is Regulated by Feedback Loops � 2 Types: Positive & Negative feedback systems Basically, your endocrine system monitors the body for information (feedback) and responds accordingly

Positive Feedback �The production of certain hormones triggers a response to produce more of that hormone �Often seen in situations of great stress: i. e. Adrenalin: you’re scared, you produce adrenalin. � Your body senses adrenalin and produces more adrenalin. Childbirth hormones: a woman giving birth produces hormones to help get the baby out. � Her body senses those hormones and produces more.

Negative Feedback �There is a “set point, ” an optimal level for each factor (ex: body temp: 98. 6 °F, blood p. H: 7) �The body compares the actual level of a factor to the set point. �A “negative” result means that the actual level is either higher or lower than what it should be �The endocrine system launches the correct response

Example of Negative Feedback Monitor body temperature It is NOT 98. 6 °F Too High Continue to… Is it… Body temperature returns to 98. 6 °F, homeostasis achieved Too Low Endocrine system launches warming response Shivering, etc Endocrine system launches cooling response Sweating, etc