Midterm Flashcards
Define homeostasis
relative consistency of physico-chemical properties of the internal environment of an organism being maintained by regulation
Define variable
characteristic of the internal environment that is monitored and controlled
Define set point
ideal or normal value of the variable that is previously set/ stored in memory
Define sensor
detects changes in variable and feeds that info back to integrator
Define controller/comparator
integrates and compares data from sensory and stored set point data
-calculates error and initiates effector
Define effector
mechanism that has an effect on the variable
What are some factors that influence the outcome of an exposure to a stressor
age, nature, personal appraisal of stressor, intelligence, emotional response
Define allostasis
maintaining stability through change
Define adaptation
changes to the human system induced by exposure to an environmental stressor
Define adaptation (genotypic)
genetically fixed condition of species or its evolution which favours survival in a particular total environment
-irreversible
Define adaptation (phenotypic)
-acclimation/acclimatization
-changes that reduce the physiological/ emotional strain produced by stressful components of environment and occurring within the lifetime of the species
-reversible
Define habituation
reduction of responses to repeated stimulation
Define acclimation
physiological/behavioural changes occurring within organism which reduces strain/enhances endurance of strain caused by experimentally induced stressful changes in particular climatic factors
-become accustomed to new climate
Define acclimitization
physiological/behavioural changes occurring within lifetime of an organism that reduce strain caused by stressful changes in natural climate (seasonal/ geographical)
Define temperature
a number defined as the average kinetic energy of a system based on the random motion of atoms within an object
Explain the zeroth law of thermodynamics
if object a and b have the same temperature, and object b and c have the same temperature, then object a and c have the same temperature
Describe the first law of thermodynamics
the internal energy of a system increases if energy is added via heat, and it decreases if energy is lost via work done by the system
What is heat
energy that is transferred from one body to another
-transfer into a system is positive heat gain
-transfer out of a system is negative heat loss
(follows a gradient, from hot to cooler)
-objects will transfer heat until they maintain a constant temo and reach thermal equilibrium
Define conduction
transfer of heat between surfaces that are in contact with each other
What variables does heat flow depend on
-thermal conductivity of the object
-the size of the exposure area
-the difference in temp between objects
-the thickness of the object
Thermal conductance is dependent on ____________
thickness
Low thermal conductance value= _______
good resistor to heat
(there will be less transfer of heat between the objects)
Define specific heat
the amount of heat required to raise the temp of an object by 1deg
What does it mean if something has a high specific heat?
it is harder to change the temp/ requires a lot of energy to do so
(water and our bodies have high specific heat)
Subcutaneous fat has a ______ specific heat and _______ thermal conductivity
high
poor
*due to this it plays a major role in heat gain and heat retention
In hot weather, do we want clothes that are good thermal conductors or bad?
Good
-having high thermal conductive fabrics lets heat pass from the hot body to the cooler air on the other side of the shirt
(thermal resistant fabric won’t easily move heat away from the body)
Define convection
heat transfer within and because of a fluid (gas or liquid)
-heat rises, cold sinks
-temp differences within fluids create currents
What role does convection play in regards to the clothes you wear?
there is a microenvironment between your clothes and your skin
-as your body heats up, it warms the microenvironment so now your body is perceiving the environment temp as the microenvironment temp
-this is why you have to take layers off when working out outside
Define radiation
transfer of heat by electromagnetic eaves
-objects will absorb, reflect, store, and emit radiation
_________ objects absorb light, __________ objects reflect light
black/dull (get more heat through radiation)
light/reflective (don’t gain much heat from radiation)
Define emissivity
a measure of a material’s radiating efficiency
-higher number= better at radiating energy
(human skin has good emissivity)
Define thermoregulation
process of regulating body temp
-occurs via basal metabolic heat production, food, and physical activity
___________ is one of the primary homeostatically controlled processes in the human body
thermoregulation
