Chapter 10

• Endothermy is when an animals tissues are warmed by its metabolic production of heat.
• Thermoregulation refers to the maintenance of a relatively constant tissue temperature
• Ectotherms body temperature is determined by the thermal conditions outside their bodies.
• Poikolotherms is another way to define ectotherms because they have variable body temperatures.
• Ectotherms have high body temperatures in warm environments and low body temperatures in cool environments.
• An individual may exhibit different thermal relations to its environment at different times.
• Thermal relations may also exhibit spatial variation, differing from one region of an animals body.
• Heterothermy refers to a difference in thermal relations from one time to another, or one body region to another, within a single individual.
• Hibernating species of mammals exemplify temporal heterothermy.
• Temperature is always a major factor in the lives of individual animals, regardless of the particular thermal relation the animals exhibit.
• The environmental temperature is also known as ambient temperature.
• Ambient temperature is a principal determinant of an animals metabolic rate and therefore the rate at which the animal must acquire food.
• The temperature of an animals tissues universally plays a principal role in determining the functional properties of the tissues.
• Temperature also exerts major effects on the properties of entire ecological communities.
• Temperature affects a species geographical range.
• The temperature of a substance is a measure of the speed or intensity of molecular random motions.
• Heat is a form of energy that a substance possesses by virtue of the random motions of its atomic-molecular constituents.
• The amount of heat in a piece of matter thus depends on the number of atoms and molecules in the piece, as well as the speed of each atom and molecule.
• Temperature dictate the direction of heat transfer.
• Heats always moves by conduction or convection from a region of high temperature to one of low temperature.
• The transfer of heat raises the temperature of the object receiving heat and lowers the temperature of the object losing heat.
• Objects are at thermal equilibirum when their temperatures are the same because then heat does not tend to move in net fashion between them.
• The four heat-transfer mechanisms are conduction, convection, evaporation, and thermal radiation.
• An animal may gain heat by one mechanism while it simultaneously loses heat by another.
• For the body temperature of animal to be constant, the sum total of its heat gains must equal the sum total of all its heat loses.
• Conduction and convection can be discussed together.
• Conduction in the transfer of heat through a material substance that is macroscopically motionless.
• Conduction mechanistically has much in common with simple solute diffusion.
• Convection is the transfer of heat through a material substance by means of macroscopic motion of the substance.
• Fluid flow is required for convection.
• Heat faster by convection is must faster than by conduction.
• Evaporation of body water from the respiratory passages or skin of an animal takes heat away from the animals body.
• The amount of heat requires to vaporize water, called the latent heat of vaporizations, depends on the prevailing temperature.
• Thermal-radiation heat transfer occurs by means of beams of radiant energy that all objects emit and that travel between objects at the speed of light.
• Thermal-radiation heat transfer allows objects to exchange heat at a distance.
• Ecothermy is by far the most common type of thermal relation exhibited by animals.
• Aquatic poikilotherms typically have body temperatures that are essentially the same as water temperature.
• Terrestrial poikilotherms do not necesarily match the temperature of the air because of thermal-radiation what transfer.
• Poikilotherms often exert behavioral control over their body temperatures.
• Behavioral thermoregulation when a poikilotherm behaviorally maintains a relatively constant body temperature.