January 24, 2017 Journal: What is the function of the endocrine system? After you complete this journal, hand in your journals. You should have at least 15 entries.

Introduction to the Endocrine System

Endocrine System Series of organs and glands that secrete hormones into your bloodstream

What does the Endocrine System control? Growth & development Reproduction Reducing body stress Maintaining water and nutrient balance Regulating cellular metabolism and energy balance Maintain homeostasis

Endocrine Glands

Hypothalamus, Pituitary Glands, and Pineal Gland

Thyroid & Parathyroid Gland

Capsule Adrenal Glands

Pancreas

Ovaries and Testes

Hormones Chemical messengers released by endocrine glands that are released into the blood stream and travel all over your body Cause a widespread response

Chemical Messenger Comparison Neurotransmitters Hormones Chemical Messenger Released at chemical synapse Released into bloodstream Intended for close target Travels to distant targets Effect happens quickly Effect takes time Effect wears off quickly Effect lasts longer Affects single cell Affects many cells

How Hormones Work Hormones bind to receptors on the outside or inside of target cells If the receptor is on the outside… It changes cell membrane permeability It changes enzyme activity inside the cell If it binds to receptors inside the cell… Its called a steroid Interact directly with the cell’s DNA to change cell activity

Control of Endocrine Activity Most endocrine organs are active all the time, but the amount of hormone produced changes Homeostasis including the amount of hormones produced is regulated through positive and negative feedback loops

Control of Hormones Neural Control Hormone levels controlled by the nervous system Ex: Adrenal gland secretes hormones to prolong sympathetic response

Control of Hormones Hormonal Control Glands are arranged in a hierarchy and each regulate the gland below them in the chain

Control of Hormones Humoral Control Hormone levels controlled by body fluids