Endocrine System Function: Endocrine System - For glands to release products into bloodstream to deliver messages throughout the body. Regulation Is the control & coordination of other life functions to maintain HOMEOSTASIS (Stability) an organ made of epithelial cells that makes & releases substances Hormone Chemicals released in one area of the body, travels in bloodstream, & affects activities of cells in another area of the body Target Cells Cells with receptors specific for a hormone. If the shape does not match, the hormone has no effect When You Think About The Endocrine System, What Important Words Come To Your Mind? What Do Endocrine s Release (Secrete)? Hormones 1
After Organ Releases Hormones, Where Do Hormones Travel Next? Bloodstream Where Do Hormones Travel After The Bloodstream? To Target Cells Would A Hormone Connect With A Non-Target Cell? Why Or Why Not? No Specific Receptor For The Hormone To Attach Target Cells Secreting Cells Name 2 Examples Of Target Cells Tissues or s 2
Which 2 Organ Systems Work Together To Regulate Other Organ Systems? Endocrine System & Nervous System Comparing The Nervous System Endocrine System Telephone Impulses (electrochemical) that carry messages that travel from one cell to another cell. Radio Broadcast Chemicals (hormones) released that reaches almost every cell in the body. Made Up Of Nervous System Nerve cells (neurons) Controlled by Electrochemical impulses released in synapse Response time Effects Quick, rapid response Short duration (short time) Endocrine System s Hormones(chemicals) released in bloodstream Slow response Long duration (longer time) 2 Types of s Exocrine s - release hormones - release hormones into ducts (tubes) directly into bloodthen to the organ. stream (ductless). Ex: sweat tears digestive juices Endocrine s Ex: thyroid pancreas others Exocrine Duct Endocrine Ductless Exocrine or Endocrine s? 3
Exocrine or Endocrine s?? List the Endocrine s 1. Hypothalamus 2. Pituitary 3. Thyroid 4. Parathyroid 5. Adrenal 6. 7. Ovaries 8. Testes Hypothalamus Pituitary Parathyroid Pituitary Parathyroid s Hypothalamus Thyroid Thyroid Adrenal s Adrenal Ovaries (female) Ovaries (females) Testicles (males) Testes (male) Can You Explain How a Thermostat Works in Your Home? An Example of Homeostasis Is controlled by Negative Feedback (Feedback inhibition). Negative Feedback - the process where a stimulus produces a response that opposes the original stimulus. Ex: Thermostat ON, Increases Temp, Shuts OFF, Decreases Temp, Thermostat ON 4
Feedback Mechanism A way to self adjust. Endocrine s Detects the proper amount of hormones in the body. If not, will increase or decrease the hormone amount for proper regulation. Feedback Mechanism Example #1: Case Study Mario ate two boxes of chocolate chip cookies with a glass of milk. How do you think his body will help regulate the excess sugar level in his bloodstream? Let s Use Our Chain of Events Diagram. secretes insulin secretes insulin into blood to help sugar enter the cells. Raises glucose, if glucose rises above set point Glucose Regulation Lowers glucose, if glucose falls below set point Food Stomach secretes glucagon Bloodstream Happy cells Dynamic Equilibrium Between Which Times Represent Stability (Homeostasis) of Blood Sugar? Homeostasis Stability 5
Feedback Mechanism Example #2: Case Study Amanda went for a physical and the doctor reported that her thyroid levels were normal. Let s Use Our Chain of Events Diagram. H I G H Feedback Mechanism Hypothalamus Inhibit TRH Pituitary Inhibit TSH Thyroid Thyroxine Target Cells Stimulate Stimulate L O W Increase Metabolism Questions What will happen if Amanda s blood work showed a high thyroxine level? Her hypothalamus & pituitary glands will be inhibited (stopped) from releasing their substances. So no more thyroxine will be made. What will happen if Amanda s blood work showed a low thyroxine level? Her hypothalamus & pituitary glands will be stimulated to release their substances. So more thyroxine will be made. s Pituitary Location: Bean shaped in base of skull. Hormones: See chart Function: Controls many body functions & actions of other glands Disorders: Gigantism, Dwarfism 6
Hypothalamus Location: above & attached to posterior pituitary gland. Hormone: TRH Function: 1. Controls the secretions of the pituitary gland. 2. Because the endocrine & hypothalamus are closely connected, the nervous & endocrine syst. coordinate body activities together. Thyroid Location: Base of the neck Hormone: Thyroxine (made of iodine) Function: Regulate the body cells metabolism by increasing the rate of cellular respiration, protein, carb, & fat metabolism. Disorders: Hyperthyroidism, Hypothyroidism, Cretinism Parathyroidism s Location: Back surface of the thyroid gland. Hormone: PTH Function: Increase calcium level in blood promotes nerve &muscle function help bone structure Adrenal s Location: two pyramids on top of kidneys Hormones: 2 Parts: 1. Cortex: secretes corticosteriods, cortisol, aldosterone 2. Medulla: epinephrine, norepinephrine Function: Help deal with stressful situations (fight or flight) Adrenal Hormones Aldosteroone- reabsorbs Na+, excretes K+ Cortisol- control rate of metabolism: carbs, fats, proteins Epi, norepinephrine- increase heart rate, sweating, wider airway passages, increase glucose released, increase BP, & blood flow. Location: Abdomen Hormone: Insulin & Glucagon from cells called (islets of Langerhans) - Beta cells produce insulin - Alpha cells produce glucagon 7
Function: 1. Insulin (decreases sugar) by stimulating liver & muscle cells to remove sugar in the blood. 2. Glucagon (increases sugar) by stimulating liver to break down gylcogen into glucose & send into blood. Location: Ovaries (females) Hormone: estrogen progesterone Functions: 1. Produce eggs 2. secrete sex hormones Gonads Location: Testes (males) Hormone: testosterone Functions: 1. Produce sperm 2. Secrete sex hormones Sex Hormones Estrogen - dev. Eggs - breast dev. - widening hips - pubic hair Progesterone - prepares uterus for implantation Testosterone - dev. sperm - facial hair - increase body size - deepening of voice Medical Disorders Malfunctions Medical Conditions Diabetes - produces a little or no insulin. Goiter - An enlarged thyroid gland due to iodine deficiency (not enough). Gigantism -Excess (more) of growth hormone (GH) from a benign pituitary tumor. Dwarfism -A deficiency (less) of growth hormone (GH), by the pituitary gland or a gene mutation. Diabetes Type1: produces a little or no insulin. Type2: becomes resistant to effects of insulin or produces a little insulin. Effect: Raises blood sugar Treatment: Insulin, oral med., diet, exercise 8
Diabetes Risk Inactivity Poor Diet Overweight Advancing Age Heredity Thyroid Disorders Disorders: 1. Hyperthyroidism (to much thyroxine secreted) -results in increased heart and metabolic rates, increased blood pressure and weight loss. 2. Hypothyroidism (to little thyroxine secreted) -results in lack of energy, weight gain, and sometimes a goiter enlargement of thyroid Goiter An enlarged thyroid gland due to iodine deficiency (not enough). Can be from autoimmune condition. Normal Thyroid Goiter Effect: Not enough thyroid hormone made. Treatment: Iodine pills, hormone therapy pills. 9
Pituitary Disorders Disorders: 1. Gigantism: too much growth hormone (GH) secreted in early childhood 2. Dwarfism: too little GH secreted in early childhood Gigantism (Giantism) Excess (overproduction) of growth hormone (GH) from a benign pituitary tumor. Effect: Causes overgrowth of long bones. Treatment: Surgery, radiation therapy, medication. Dwarfism A deficiency of growth hormone (GH), by the pituitary gland or a gene mutation. Effect: short stature (2ft 8in-4ft 8in) Treatment: surgery for bone problems, hormone therapy (injections) 10