Presentation on theme: "Homeostasis and Feedback in the Body"— Presentation transcript:
1 Homeostasis and Feedback in the Body Colorado Life Science 2.6: Cells, tissues, organs, and organ systems maintain relatively stable internal environments, even in the face of changing external environments
2 What is homeostasis? Process that occurs in all living things All organ systems work together to achieve ___________.Ability of an organism to maintain its internal environment, despite changes to its internal or ________ environment!all images generated by Microsoft Clip Art Gallery
3 How does homeostasis work? pathwaysA cellular relay race!Specific organs and structures must communicate with each other in response to changes in the bodyKeeps levels of certain processes within a normalall images generated by Microsoft Clip Art Gallery
4 What things in your body need to be kept within a range? Body TemperatureBlood pressureBlood pHO2 and CO2 concentrationOsmoregulation-Water balanceBlood glucoseall images generated by Microsoft Clip Art Gallery
5 How Does it Work? Stimulus Receptor Integrating center Effector ResponseReverses the stimulusall images generated by Microsoft Clip Art Gallery
6 Example: Consider temperature in your home…. Stimulus- low thermal energy in the room (it’s cold)Receptor- sensor in thermostatIntegrating center- thermostatEffector- HeaterResponse- increased thermal energy (it’s warmer)
7 Negative FeedbackAlso called feedback Way in which MOST homeostatic mechanisms workStimulus produces a response that opposesor the original stimulusIn other words, theproduct of a negativefeedback pathway inhibitsor shuts down the originalsignal.
10 You can think of negative feedback like dueling mechanisms- What goes up, must come down! _______________________ Sweating (cooling) vs. shivering (warming)Blood PressureVasconstriction vs. vasodilationOsmoregulationHypotonic vs. hypertonicall images generated by Microsoft Clip Art Gallery
11 Positive FeedbackABTakes body out of homeostasis (which can be necessary in certain circumstances)Stimulus causes a _________ that causes more of the stimulus
12 Positive Feedback Examples Increase in births increases population which increases births – and so on.
13 Positive Feedback Examples in Our Body Blood clotting ______________ Injured tissue signals platelets to be activated, activated platelets produce chemical signal that activates more platelets______________The hormone oxytocin signals a contraction, which signals they brain to produce more oxytocin
14 Additional Examples…Identify the following as examples of positive or negative feedback loops within the body?
15 Homeostasis & the Integumentary System Functions of Integumentary System:ProtectionBody Temperature RegulationExcretionInformation GatheringVitamin D Production
16 Homeostasis: Body Temperature Regulation If cold, ___________ generates heat and goose bumps and constricted blood vessels help decrease the heat loss from skinIf hot, __________ blood vessels allows excess heat released from skin and sweating allows energy to leave the body
28 Processes of the Digestive System _________ – food into mouthDigestion – mechanical and chemical break down – starts in mouth, continues to break down in stomach and small intestine___________ – bloodstream absorbs nutrients in small intestine and absorbs water in large intestineElimination – Waste eliminated through anus
29 Homeostasis- The Digestive & Circulatory & Endocrine Systems- Blood Sugar Regulation! Glycogen- Stored glucose (polysaccharide of glucose)Glucagon- Hormone secreted by pancreas that _________ blood sugar (break down glycogen into glucose)Produced by alpha-cells of the pancreasReleased into the circulatory system when blood glucose is lowSignals the liver to break down glycogen into simple glucoseInsulin- Hormone secreted by the pancreas that _________ blood sugar (glucose to glycogen)Produced by beta-cells of the pancreasReleased into circulatory system when blood glucose is highFacilitates the transport of glucose into target cells
30 Homeostasis & the Digestive System Blood sugar regulation:
33 Food for thought…On average, how many organ systems are involved in each of the processes we’ve explored?Are there any organ systems that you see in all of these processes?What might happen to these pathways if just one system was not functioning properly?all images generated by Microsoft Clip Art Gallery