Catalyst: (pg. 100) Name one hormone that you read about this week Agenda Catalyst Endocrine system MELCon Summary Homework Objectives: SWBAT Identify the function of hormones within the human body Explain how the nervous and endocrine systems work together to maintain homeostasis

Maintaining Homeostasis Animals rely on 2 systems for regulation of Homeostasis – endocrine system system of glands – secrete chemical signals directly into blood – chemical travels to target tissue – target cells have receptor proteins – slow, long-lasting response – nervous system system of neurons – transmits “electrical” signal & release neurotransmitters to target tissue – fast, short-lasting response

Endocrine System & Hormones

Why are hormones needed? – chemical messages from one body part to another – communication needed to coordinate whole body – daily homeostasis solute levels in blood – glucose, Ca ++, salts, etc. metabolism growth development maturation reproduction The Endocrine System Produces Hormones growth hormones

Regulation by chemical messengers axon endocrine gland receptor proteins target cell Neurotransmitters released by neurons Hormones release by endocrine glands receptor proteins hormone carried by blood neurotransmitter Lock & Key system

Learning Check 1.How do hormones maintain homeostasis? 2.What are the two systems are the source of the body’s chemical signals? 3.What system is composed of neurons? 4.What system is composed of glands? 5.How are nerve signals different than hormone signals?

Classes of Hormones Protein-based hormones – Stored in endocrine cells until needed Metabolism Growth Reproduction – Insulin, growth hormones Amino Acid based hormones – Bind to receptors OUTSIDE of the cell – Activate gene expression from DNA and the building of proteins Lipid-based hormones – Steroids Sex hormones (estrogen, androgen, progesterone) Pass into the nucleus of a cell and bond to specific receptors that activate gene expression from DNA insulin

Maintaining homeostasis high low hormone 1 lowers body condition hormone 2 gland specific body condition raises body condition gland Negative Feedback Model

Nervous & Endocrine systems are linked Hypothalamus = “master nerve control center” – nervous system – receives information from nerves around body about internal conditions – releasing hormones: regulates release of hormones from pituitary Pituitary gland = “master gland” – endocrine system – secretes broad range of “tropic” hormones regulating other glands in body hypothalamus pituitary posterior anterior

Thyroid gland anterior pituitary gonadotropic hormones: follicle- stimulating hormone (FSH) & luteinizing hormone (LH) Mammary glands in mammals Muscles of uterus Kidney tubules posterior pituitary thyroid-stimulating hormone (TSH) antidiuretic hormone (ADH) Adrenal cortex Bone and muscle Testes Ovaries Melanocyte in amphibian adrenocorticotropic hormone (ACTH) melanocyte-stimulating hormone (MSH) oxytocin prolactin (PRL) growth hormone (GH) tropic hormones = target endocrine glands

Learning check 2 1.What are the three classes of hormones? 2.For each class identify where they activate within the body (where the receptors are) 3.Is your bodies use of hormones considered positive or negative feedback? EXPLAIN your answer using the definition of the feedback loop you chose. 4.What are the ‘master controls’ in the nervous AND endocrine system? 5.Where are they found in the body? 6.How do they work together to maintain homeostasis?

MELCon Summary Purpose: Describe how the endocrine system and the nervous system work together to maintain homeostasis. M- What is homeostasis? What internal balances are maintained by your body? How do your body systems work together to maintain balance? E- Use 2 examples from this week to explain how the endocrine system and the nervous system work together L- Use the examples to explain homeostasis Con- Restate the big idea and connect examples back to the main idea.