Homeostasis PowerPoint Presentation PDF

‫‪HOMEOSTASIS‬‬ ‫)ما ترى فى خلق الرحمن من تفاوت(‬  1.5: Maintenance of Life Life depends on five (5) environmental factors: Water Food Oxygen Heat Pressure 2 Requirements of Organisms W...

‫‪HOMEOSTASIS‬‬ ‫)ما ترى فى خلق الرحمن من تفاوت(‬  1.5: Maintenance of Life Life depends on five (5) environmental factors: Water Food Oxygen Heat Pressure 2 Requirements of Organisms Water - most abundant substance in body - required for metabolic processes - required for transport of substances - regulates body temperature Food - provides necessary nutrients - supplies energy - supplies raw materials 3  Requirements of Organisms Oxygen (gas) - one-fifth of air - used to release energy from nutrients Heat - form of energy - partialy controls rate of metabolic reactions Pressure - application of force on an object - atmospheric pressure – important for breathing - hydrostatic pressure – keeps blood flowing 4  Human affects and is affected by his environment : External environment Internal environment  In the average young adult male, 18% of the body weight is protein and related substances, 7% is mineral, and 15% is fat. The remaining 60% is water  Homeostasis* Homeostasis (from Greek : ὅμοιος, "hómoios", "similar", and στάσις, stásis, "standing still" is the property of a system that regulates its internal environment and tends to maintain a stable, relatively constant condition of properties such as temperature or pH. It can be either an open or closed system. In simple terms, it is a process in which the body's internal environment is kept stable. It was defined by Claude Bernard and later by Walter Bradford Cannon in 1926, 1929 and 1932. (the various physiologic arrangement which serve to restore the normal state once it has been disturbed).  Homeostasis* * Maintaining of a stable internal environment “physiological normal” dynamic involves maintaining the volume and composition of body fluids – intracellular (ICF) – extracellular (ECF) 9  The actual environment of the cells of the body is the interstitial component of the ECF. The normal cell function depends on the constancy of this fluid,  W.B. Cannon coined the term homeostasis to describe "the various physiologic arrangements which serve to restore the normal state, once it has been disturbed," HOMEOSTASIS IS MAINTANING:-  THE INTERNAL ENVIRONMENT CONSTANT INSPITE OF CHANGES IN SURRONDING.  THE STEDY STATE DURING CHANGES OF  THE FUNCTION OF ALL OF THE ORGAN SYSTEMS OF THE BODY IS TO ENSURE THAT THE PHYSICAL AND THE CHEMICAL CHARECTERISTICS OF TISSUE FLUID REMAINS CONSTANT WITHIN HOMEOSTATIC. ARE ALL THE MECHANISMS:- AUTOMATIC REACTIONS WHICH TAKE PLACE IN THE BODY IN RESPONSE TO CHANGES IN EXTERNAL AND INTERNAL ENVIRONMENTS AND WHICH TEND TO CORRECT ALL DIVIATIONS FROM NORMAL Homeostatic Control Mechanisms Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. components – receptor monitors changes input to control center – control center evaluates input and generates output – effector receives output from control center produces a response 15 Homeostatic Control Mechanisms Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. continually disrupted by internal and external environments balance regulated by – nervous action potentials rapid – endocrine hormones slow 16 Homeostatic Control Mechanisms Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The hypothalamus detects the deviation from the set point and signals effector organs. Receptors Effectors Thermoreceptors Skin blood vessels send signals to the dilate and sweat glands control center. secrete. Stimulus Response Body temperature Body heat is lost to rises above normal. surroundings, temperature drops toward normal. too high Normal body temperature 37°C (98.6°F) too low Stimulus Response Body temperature Body heat is conserved, drops below normal. temperature rises toward normal. Receptors Effectors Effectors Thermoreceptors Skin blood Muscle send signals to the vessels constrict activity control center. and sweat glands generates remain inactive. body heat. Control center The hypothalamus detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals 17 muscles to contract Involuntarily. Homeostatic Control Mechanisms There are two (2) types: Negative feedback mechanisms Positive feedback mechanisms 18 THE -VE FEEDBACK INPUT DIVIATION FROM CONTROL NORMAL RECEPTOR COMPARATO SET R NORM CONTROL CENTER EFFECTOR ORGANS. CONTROLLED VARIABLES CORRECTION OF DIVIATIONS FROM -VE ERROR SIGNAL Homeostatic Control Mechanisms Negative feedback summary: Prevents sudden, severe changes in the body Reduces the actions of the effectors Corrects the set point Causes opposite of bodily disruption to occur, i.e. the ‘negative’ Limits chaos in the body by creating stability Most common type of feedback loop Examples: body temperature, blood pressure & glucose regulation 20 REGULATION DEHYDRATIO N OSMOCEPTE 300 RS THIR HYPOTHALAMI ST C NEUCLEI POST -VE PETUTA RY ADH CONCENTRAT ED URINE Homeostatic Control Mechanisms Positive feedback summary: Increases (accelerates) the actions of the body Produces more instability in the body Produces more chaos in the body There are only a few types necessary for our survival Positive feedback mechanisms are short- lived Controls only infrequent events that do not require continuous adjustments Considered to be the uncommon loop Examples: blood clotting and child birth 22 BENIFITAL +VE FEEDBACK  CLOTT FORMATION IN A RUPTURED VESSLE.  UTERINE CONTRACTIONS DURING CHILDBIRTH.  Na + CHANNELS IN NERVE  Animation: Positive and Negative Feedback Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. 24 ‫ما ترى فى خلق الرحمن(‬ ‫من تفاوت فارجع البصر‬ ‫هل ترى من فطور ثم‬ ‫ارجع البصر كرتين‬ ‫ينقلب إليك البصر خاسئا‬ ‫) وهو حسير‬