Animals Function and Development Dr Waters Office Hours M 9 00 9 50 am T 2 30 3 20 pm W 2 00 2 50 pm R 1 30 2 20 pm Homeostasis vs Equilibrium Homeostasis Any process that actively maintains a fairly stable environment This requires energy The body monitors its internal environment and takes action to correct disruptions that threaten its normal function A dynamic steady state where the internal environment fluctuates within a set range of values Equilibrium When the internal and external environments are balanced and unchanging When all of the variables of a process are in balance and do not change Homeostasis regulates Body temperature ion concentration glucose glycogen water balance pH oxygen metabolism cell division carbon dioxide blood pressure heart rate and more In fl o w high limit low limit set point Homeostasis Any process that actively maintains a fairly stable environment Set point the ideal value High and low limits the acceptable range of change What will happen to In flow if the water level rises to the red arrow increase decrease or not change Homeostasis Any process that actively maintains a fairly stable environment In fl o w high limit low limit set point Negative Feedback Loops resist change maintain homeostasis If it is too high then lower it If it is too low then raise it If it is ok then change nothing Homeostasis Any process that actively maintains a fairly stable environment Negative Feedback Loops resist change maintain homeostasis If it is too high then lower it If it is too low then raise it If it is ok then change nothing Homeostasis Any process that actively maintains a fairly stable environment Negative Feedback Loops resist change maintain homeostasis If it is too high then lower it If it is too low then raise it If it is ok then change nothing Homeostasis Any process that actively maintains a fairly stable environment Negative Feedback Loops help maintain homeostasis Stimulus When blood pressure temperature or other parameter changes Sensor measures and transmits the change to IC Integrating Center IC makes decision on what to do about information transmitted by sensor If too high then lower it If too low then raise it If ok then change nothing Target sometimes called Effector Implements any change decided on by IC Stimulus Sensor Input Signal Output Signal Target Integrating Center k c a b d e e f Response What happens when the Target actually carries out the Integrating Center s decision Response Homeostasis Any process that actively maintains a fairly stable environment Homeostatic Regulation of Blood Pressure Baroreflex Identify the Stimulus Identify the Sensor What does it do Where is it located Identify the Integrating Center What does it do Where is it located Identify the Target What might it do Where is it located What structures transmit action potentials Examples Blood Pressure Baroreceptor Action Potentials Vasomotor Center Action Potentials Blood Vessels Response k c a b d e e f Homeostasis Any process that actively maintains a fairly stable environment Blood Pressure Baroreceptor Action Potentials Cardioinhibitory Cardioacceleratory Center Center Vasomotor Center k c a b d e e f Action Potentials Action Potentials Heart Heart Action Potentials Blood Vessels Response Response Response The Circulatory System Use a sphygmomanometer to measure blood pressure Cuff is pumped out so there is no blood flow through brachial artery Pump pressure is released as you listen for the sound of turbulent flow When blood can just squeeze through inflated cuff you can hear the turbulent flow Sounds of Korotkoff When sounds of Korotkoff are first audible cuff pressure systolic pressure Continue to release pressure on cuff When brachial artery is no longer constricted no more turbulent flow When sounds of Korotkoff can no longer be heard cuff pressure diastolic pressure The Circulatory System The blood pressure during ventricular systole is called the systolic pressure The blood pressure during ventricular diastole is called diastolic pressure In general both decrease as blood moves further from the heart BLOOD PRESSURE DRIVES BLOOD FLOW No Pressure No Flow 5 quarts of blood in an average human Not enough to support all organs at their highest O2 consumption levels Blood flow regulated Vasoconstriction Vasodilation Neural circuits in the brain IC regulate heart rate strength of contraction vasoconstriction and dilation throughout the entire body to regulate blood pressure
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