Do Now (looseleaf) What is the difference between a motor neuron, sensory neuron and an interneuron? How do nerves communicate with one another? How does a neurotransmitter know what receptor to go to? Explain

Do Now (looseleaf) How do neurotransmitters and hormones travel around the body? Where are neurotransmitters and hormones secreted from? How are neurotransmitters and hormones similar? Using your knowledge, predict which system causes a change in your body faster (endocrine or nervous)

DO NOW #11 Finish early: Work on Do Now #12

DO NOW Complete section “G” on the back cover of your note packet (the one you received yesterday)

DO NOW Complete (Section “E”)…one question Complete (Section “F”)…chart ON BACK OF NOTE PACKET

Endocrine System Glands, Hormones, Receptors, Target Cell, Non-target Cell, Negative Feedback

Endocrine System How does the endocrine system help maintain homeostasis? Controls and coordinates the body’s response to changes in the environment using hormones! Is this the same function as the nervous system? Explain Yes! Both perform REGULATION So are the nervous and endocrine systems the same thing? Explain Are you crazy? NO Nervous system uses nerves and neurotransmitters Endocrine system uses glands and hormones

What organs are in the endocrine system? Glands Synthesize and secrete hormones What are hormones? Hormones Chemical signals secreted in one area of the body that affect other areas Hormones are proteins with a specific shape Travel in blood vessels Allow body to RESPOND to CHANGE

How do hormones have a specific shape? *Hormones are proteins! Sequence of amino acids determines shape of proteins So, how do hormones work? Different glands secrete different hormones Specific hormones are secreted into the blood and travel everywhere in the body! Hormones only affect / attach to certain cells, called target cells How do hormones know what cells to affect or deliver a message to? Target cells recognize specific hormones because hormones have specific shapes that only fit in certain cell receptors!

Specific Hormones & Specific Receptors Hormones and receptors fit together like a: Lock and Key Hormone Target Cells Can’t read signal Receptors Secreting Cell (Gland Cell) Can’t read signal Non-target Cells Why? Blood Vessel

Binding of a hormone to a receptor on the surface of its target cell causes… A specific reaction Lets take a look at the types of glands, hormones and the reactions they cause!

Glands of the Human Body

Pituitary Gland Also known as… The MASTER Gland Location - BRAIN Hormone(s) Target(s) Function(s) TSH (Thyroid Stimulating Hormone) Thyroid Gland Causes Thyroid to secrete its hormone Affects metabolism FSH (Follicle Stimulating Hormone) Ovaries / Testes Stimulates sperm and egg development Growth Hormone Bones Stimulates elongation of the bones

Thyroid Gland Location - Neck Hormone(s) Target(s) Function(s) Thyroxine Various Cells Increases metabolism, digestion and energy levels

Adrenal Gland Location – Top of Kidneys Hormone(s) Target(s) Function(s) Epinephrine / Adrenaline Heart Blood Vessels Skin Muscles Emergency Response “Fight or Flight” Response

Pancreas Location – Behind Stomach Hormone(s) Target(s) Function(s) Insulin Body Cells Especially Liver & Muscle Cells Lowers blood sugar levels Stores sugar in in liver and muscle cells as glycogen Glucagon Raises blood sugar levels Stimulates the release of sugar stored in liver cells

Gonads – Testes & Ovaries Hormone(s) Target(s) Function(s) Estrogen & Progesterone Ovaries & body cells Influences development of female secondary sex characteristics Testosterone Testes & body cells Influences development of male secondary sex characteristics

Type 2 Diabetes Type 1 Diabetes (insulin-dependent diabetes) The body does not produce insulin. Developed before 40th birthday, often in early adulthood or teenage years. Only about 10% of all diabetes cases are type 1. Patients with type 1 diabetes will need to take insulin injections for the rest of their life. They must also carrying out regular blood tests and following a special diet. Type 2 Diabetes Body does not produce enough insulin for proper function, or the cells in the body do not react to insulin (insulin resistance).

How is hormone production regulated? Hormones are NEVER released at a constant rate! Example: Growth Hormone – If released at a constant rate… You would be a GIANT!! (Gigantism) Hormones are released based upon… The needs of the body

The mechanism that alters (stimulates or stops) the activity of a gland is usually an example of a FEEDBACK MECHANISM Example: Heating your home using a thermostat If the home is cool, you raise the heat, thermostat, to 70⁰F and the home begins to warm up What happens when 70⁰F has been reached? The heat will shut off because 70⁰F was reached! The heat will turn back on when the temperature is below 70⁰F

How does the process of Feedback work in your body? When is your blood glucose level low? When is your blood glucose level high? Low blood glucose usually happens when you do not eat for a while or when you workout and use the available sugar in your blood. This will lower your blood sugar, stimulus, and your pancreas will secrete glucagon to get the liver and muscle cells to release sugar into the blood. This will STOP your blood sugar from going down and increase your blood-sugar level to normal (homeostasis). High blood glucose usually happens after you eat, especially carbohydrates and sugary foods. Your blood sugar goes up (stimulus) and your pancreas will secrete insulin to store the glucose in the liver and muscle cells as glycogen. This will drop the blood sugar level down to normal (homeostasis).

Both Positive & Negative Feedback helps to… Types of Feedback: Positive Feedback – Negative Feedback – Both Positive & Negative Feedback helps to… hormone secretion continues hormone secretion STOPS Maintain Homeostasis Positive Feedback… excretion of waste, birthing a baby

Are you ready? If liver cells usually have 100 insulin receptors each, and they dropped down to only 50 each, what would happen? Draw a neurotransmitter that would attach to this receptor:

Type 2 Diabetes Type 1 Diabetes (insulin-dependent diabetes) The body does not produce insulin. Developed before 40th birthday, often in early adulthood or teenage years. Only about 10% of all diabetes cases are type 1. Patients with type 1 diabetes will need to take insulin injections for the rest of their life. They must also carrying out regular blood tests and following a special diet. Type 2 Diabetes Body does not produce enough insulin for proper function, or the cells in the body do not react to insulin (insulin resistance).

What is happening in this picture?

Blood pH lowers What happens next in this feedback process?

Lets compare the Nervous and Endocrine Systems

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