1 / 19

The Endocrine System

The Endocrine System. http://www.brightstorm.com/science/biology/the-human-body/endocrine-system/. Introduction. The endocrine system is the second part of the message-relaying system of the human body It is a system of glands that release chemical messengers into the bloodstream

wilton
Download Presentation

The Endocrine System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Endocrine System http://www.brightstorm.com/science/biology/the-human-body/endocrine-system/

  2. Introduction • The endocrine system is the second part of the message-relaying system of the human body • It is a system of glands that release chemical messengers into the bloodstream • These messengers are called hormones • These messengers act much more slowly that the neurotransmitters of the nervous system • They must travel through the blood stream to where they are needed – They do, however travel throughout the body

  3. Glands of the Endocrine System

  4. Glands of the Endocrine System • Hypothalamus • A part of the brain that secretes hormones • Tell the pituitary gland to either secrete or stop secreting • This provides a link between the nervous and endocrine system • Also produces hormones that regulate other body processes • These hormones travel to the pituitary for storage until they are needed

  5. Hormones of the Hypothalamus • Antidiuretic Hormone • Stimulates the kidneys to conserve water by producing more concentrated urine • Oxytocin • Stimulates the contractions of childbirth, among other functions

  6. Pituitary Gland (Master Gland) • Pea-sized gland attached to the hypothalamus • Posterior lobe stores hormones from the hypothalamus • Front lobe secretes pituitary hormones • Most of these control other glands

  7. Hormones Produces by the Pituitary Gland

  8. Other Endocrine Glands • Thyroid Gland – in the neck • Hormones increase the rate of metabolism in cells throughout the body • Control how quickly cells use energy and make proteins • Parathyroid gland – located behind the thyroid • Helps keep the level of calcium in the blood within a narrow range • Stimulates bone cells to dissolve calcium in bone matrix and release it into the blood

  9. Other Endocrine Glands • Pineal Gland – located at the base of the brain • Secretes the hormone melatonin which controls sleep-wake cycles and several other processes • Pancreas – located near the stomach • Produces insulin and glucagon • They work together to control blood sugar levels • Insulin causes excess blood glucose to be taken up the by liver and store it as glycogen • Glucagon stimulates the liver to break down glycogen into glucose and release it back into the blood stream • Also secretes digestive enzymes into the digestive tract

  10. Other Endocrine Glands • Adrenal Glands – located above the kidneys • Outer portion secretes cortisol which helps the body deal with stress along with aldosterone which helps regulate mineral balance in the body • Inner portion secretes the fight-or-flight hormones • Adrenalin – increases the among of oxygen and glucose going to the muscles • http://www.abpischools.org.uk/page/modules/hormones/horm8.cfm?coSiteNavigation_allTopic=1

  11. Other Endocrine Glands • Gonads – secrete sex hormones • Testes secrete testosterone • Ovaries secrete estrogen • These two hormones are responsible for the changes of puberty and the control of the production of gametes by the gonads

  12. How do hormones work? • They affect only certain cells called target cells • These target cells have specific receptors on their surface that create a matching combination with its hormone • When the hormone binds to the receptor it causes a change within in the cell • What happens depends upon if the hormone is a steroid or non-steroid • http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP13704 • http://www.youtube.com/watch?v=HrMi4GikWwQ&feature=related

  13. Steroid Hormones • Made of lipids like phospholipids and cholesterol • They are fat soluble so they can diffuse through the plasma membrane of target cells and bind with the receptors in the cytoplasm

  14. Non-Steroid Hormones • Made of amino acids • They are not fat soluble so they can’t diffuse across the plasma membrane • When they bind the trigger enzymes within the cell membrane the active other molecules

  15. Hormone Regulation • Typically Controlled by feedback mechanisms • This is a loop in which a product (hormone) feeds back to control its own production • Most involve negative feedback loops • Keeps the concentration within a very narrow range

  16. Negative Feedback http://www.youtube.com/watch?v=CLv3SkF_Eag

  17. Endocrine System Disorders • Hypersecretion • Too much • Usually caused by a tumor • Too much growth hormone leads to gigantism • Hyposecretion • Too little • Type I diabetes

  18. Hormone Resistance • Normal amounts of hormone but target cells do not respond to the hormones • Type II diabetes • Cells don’t take up glucose • Need to follow a specific diet along with medication • Insulin doesn’t work

More Related