Topic Test 3 Flashcards
Physiology 
The study of the functions of traits that help organisms deal with problems
The chemical functions of anatomical structure, molecular traits and features of organisms 
Variables regulated by homeostasis 
PH temperature water, concentration, concentration of other ions, and substrates blood pressure 
Conduction
Heat transfer between two solids
Convection 
Heat transfer between a solid and a liquid or gas 
Radiation 
Heat transfer between bodies that are not in contact 
Evaporation 
Heat loss that occurs through energy required to evaporate water
Negative feedback loop
Stimulus, sensor, signalling, control centre (hypothalamus), effectors 
Control centre
Aka integrator compares current state to a set point, and sends a signal to initiate the appropriate response to move back towards set point 
Effector
Some structure that moves the internal conditions back towards the boys, example shivering hair, raising vasoconstriction 
Negative feedback loops 
Constant process that can move internal conditions in either direction to maintain a set point 
Conformers 
Internal conditions conform to the external conditions no homeostatic mechanism example ectotherm‘s organisms his internal depends on external temperatures 
Can behaviourally regulate their internal temp by moving to warmer and colder places
Surface area to volume ratio 
Smaller object has a larger surface area to volume ratio series object of the lowest surface area to volume ratio. Pyramid is object with the highest more surface area provides more area for diffusion. Smaller organisms, Thusi faster than larger organisms exchange requires surfaces 
Regional heterothermy
Where areas of the body vary in temperature example rabbit ears plays a role in various functions where exchange occurs 
Countercurrent heat exchange 
Heat from arterial blood flowing from coil transfers to cooler blood returning from appendages and extremities. Heat exchange within the body minimize heat loss at the surface. 
How does an ectotherm‘s metabolic rate change? 
And low temperatures, low metabolism and pace of life, normal temperatures, normal, and high temperatures metabolism 
Metabolic rate 
Amount of energy expended by an organism in a given time. Depends on temperature for ectotherms. 
 Interspecific
Between different species 
Absolute metabolic rate versus mass specific 
Absolute rate increases with increasingly large organisms
Mass specific metabolic rate is the metabolic rate per unit of body, mass and smaller organisms have a higher mass, specific metabolic rate and larger organisms because larger organisms are more efficient per unit mass 
Why are larger organisms more efficient per unit mass? 
Hypothesis is that surface area to volume ratio is high for small organisms like ground coffee beans they lose internal heat faster than whole coffee beans 
 Torpor
State of decreased physiological activity, lower temperature in metabolic rate can happen daily or can happen for days weeks or months, like hibernation can occur with occasional arousals 
Heterothermy 
Words to describe organisms to undergo torpor, whose internal temperature varies over time or whose temperature varies across the body (ex ears)
Brown adipose cells 
Burn energy for heat, have more mitochondria, and are responsible for nonshivering thermogenesis 
What makes mitochondria different in brown adipose tissue? 
Mitochondria have an uncoupling proteins, which allows protons through without creating ATP energy is just dissipated as heat
1. Burns available energy to create proton gradient, but doesn’t produce useable energy
2. Releases energy as heat none shipping thermogenesis 
Strategies ectotherms use to avoid freezing
- Avoid freezing
Torpor/hibernate,
Get rid of ice nucleating agents
Use cryptoprotectants to lower freezing point & avoid freezing - Tolerate freezing
Control where freezing happens (usually in extracellular space) through use of nucleating agents & crypto proteins
Significant drop in metabolism on freezing temps