Final Exam Study Guide ECOL 182R Q Why did circulatory systems evolve A Bigger organisms needed something to get things to individual cells Circulatory System o In flatworm all cells are within 1mm of water o No need for circulatory system o Trade off of circulatory system is that cells are not easily protected o Circulatory system allowed animals to get BIGGER focus on vertebrates Anatomy physical structure form of an organism and or it s components o Organism level o Organ system level o Organ tissue level Ex skeletal muscle o Cellular level Ex skeletal muscle cell o Macromolecular level Ex Actin Myosin filament used for muscle contraction o Molecular level Ex Actin molecules and Myosin molecule o Tissues Organs Systems o Tissues are organized into organs o Organs are organized into systems o Tissue examples Epithelia Connective tissue Smooth muscle Nerves o Organ examples Salivary glands Esophagus Stomach Liver Pancreas Small intestine Large intestine o Example of a system Digestive system Biggest Smallest Trade Offs o Animals can t do everything well or maximally o Hard to be Olympic sprinter and Olympic marathon runner o If laying eggs you either can do few large or many small assuming resources are constant o Some structures are better suited to certain tasks than others o Natural selection shapes adaptations Animal form function o In Gal pagos finches different morphologies allow them to outcompete each other for their particular food choice o Smaller beaks eat smaller seeds larger beaks eat larger seeds longer beaks eat insects and nectar Physiology study of the mechanical physical and biochemical functions of living organisms from Greek words meaning nature origin and knowledge Homeostasis regulate maintain stable conditions in the internal environments term coined by Walter Cannon o Regulates transportation of 1 Gases 2 Food 3 Salts 4 Water 5 Waste 6 Temperature o A stable internal environment of extracellular fluid makes complex multicellular animals possible o Cells are specialized for maintaining parts of the internal environment o External functions o Transport of nutrients and waste Nutrients and gases go in and waste goes out otherwise we would poison ourselves o Maintenance of ion concentrations o Internal functions o Circulation o Energy storage o Movement o Information processing o External fluctuation are minimized internally o Changes over time of a physiochemical variable such as oxygen concentration Negative feedback cycle o Set point reduces external stimulus sensor records a parameter compares sensor input with set point instructs effector effector increases the internal response to change the parameter to return it to set point set point reduces external stimulus sensor records a parameter o Ex Thermostat heat vs cool During blizzards when the window is open the heater goes on When it s hot outside and the windows are open the cooler turns on o Ex Stomach full vs empty When you re hungry you eat When you re full you re body stops wanting you to put food in it so you stop eating Temperature Allometry and Metabolism o Chemical and biological reactions tend to happen faster at higher temperatures o This affects animals via their metabolic rates o Q10 effect o How much metabolic rate changes with a 10 C change in temperature Typically between 2x and 3x Which means they need 2 3 times more food Applicable to ectotherms such as a snake Can save energy by reducing metabolic rate Does not really apply to humans because body temperature is very specific and does not drastically deviate o Metabolic rate is the rate at which oxygen and energy are consumed Often measured as oxygen consumption per unit time because that is what cellular respiration uses Higher for endotherms Because they rely on their own energy reserves for thermoregulation o Ex Cow eats more in the winter than in the summer because it needs to burn energy to stay warm Trade off is that even though we use a lot of energy we can do things at times when ectotherms cannot function because of the temperature o Cold blooded is not necessarily a correct term for ectotherms because they often thermoregulate quite well and have a warm body temperature Ex Snakes are not out in January to maintain a warm body temperature but they come out a lot in June o Ectotherms more efficient than endotherms Lizard uses 3 of energy of similar sized mammal 1 1 10 the metabolic requirements at a given Tb 2 Let Tb decrease at night 3 Overall lower activity Production vs maintenance conversion efficiency 1 4 mammal vs 50 lizard In ectotherms half the energy of food that is eaten becomes biomass when in endotherms less than 2 of the energy from food that is eaten because biomass the rest goes to metabolism and wastes energy which created high entropy o Thermoregulation cardiovascular control of heating and cooling o Peripheral vasodilation increase in diameter of blood vessels Occurs when it s hot Ex Going jogging makes skin turn red because the capillaries open to release heat o Peripheral vasoconstriction narrowing of vessel diameter Occurs when it s cold Ex Losing a ring in the cold because your finger gets thinner o Temperature exchange in environment o Conduction solid solid o Convection solid liquid gas Example could be wind o Radiation no direct contact Infrared thermal radiation everywhere everything emits this o Evaporation phase change Water being consumed takes heat away from skin Thermal Neural Zone of endotherms TNZ o Within TNZ Vasodilation constriction Posture Insulation fluff fur feathers o Below TNZ Outside TNZ Increase metabolism above basal endotherm burn o Above TNZ more energy Cool via evaporation Saved by Torpor during torpor body temperature can drop almost 50 F active temperature is 102 2 F o Hummingbirds burn energy FAST they often eat 1 5 to 3 times their weight in nectar and insects per day Heart rate may slow from 500 beats per minute to fewer than 50 Breathing may be intermittent Because tissues aren t producing oxygen at such a high rate Trade off for torpor is that it can take as long as an hour for the bird to come back into an active state Can t fly during torpor so when predators come they are out of luck Water and Temperature o Water and temperature are related because evaporation is a very useful cooling tool o For terrestrial animals evaporation is an effective cooling mechanism o For aquatic animals it is VERY difficult to be a different temperature than the water Because water has a