Notes 34.1 The Endocrine
System
How does the endocrine system help maintain homeostasis? Endocrine System •  The Endocrine system is a group of glands that release hormones into the bloodstream in order to help maintain homeostasis. •  The effects of hormones are generally more gradual and longer las<ng than those of the nervous system. Components of the Endocrine System •  The endocrine system is made up of glands that release hormones into the blood and the hormones that carry messages throughout the body. •  Examples: Adrenal gland releases adrenaline or epinephrine. Endocrine Glands Hormones
•  Chemical messengers that are released in one part of the body and affect cells in another part of the body. Target Cells
•  Cells that have a receptor for a par<cular hormone are called “target cells.” Target Cell Continued Endocrine and Exocrine
•  Endocrine glands: release hormones in the bloodstream. •  Example: Pituitary Gland •  Exocrine glands: release hormones into the diges<ve system or outside of the body. •  Example: Sweat glands, Liver Endocrine vs. Exocrine Glands Prostaglandins
•  A Hormone-­‐like substance, these modified faLy acids are released by a cell to affect other nearby cells. “Local Hormones” Hormones vs Local Hormones •  Prostaglandins are short range communica<on while hormones can travel throughout the body. Steroid Hormone
Non-­‐Steroid Hormone Endocrine/Nervous System Analogy •  An analogy is a way of comparing two things based on their being alike in some way. •  Example: The firing of a neuron could be compared to the firing of a gun. •  What do those two things have in common?