Midterm

Question 1

Define homeostasis

Answer 1

relative consistency of physico-chemical properties of the internal environment of an organism being maintained by regulation

Question 2

Define variable

Answer 2

characteristic of the internal environment that is monitored and controlled

Question 3

Define set point

Answer 3

ideal or normal value of the variable that is previously set/ stored in memory

Question 4

Define sensor

Answer 4

detects changes in variable and feeds that info back to integrator

Question 5

Define controller/comparator

Answer 5

integrates and compares data from sensory and stored set point data
-calculates error and initiates effector

Question 6

Define effector

Answer 6

mechanism that has an effect on the variable

Question 7

What are some factors that influence the outcome of an exposure to a stressor

Answer 7

age, nature, personal appraisal of stressor, intelligence, emotional response

Question 8

Define allostasis

Answer 8

maintaining stability through change

Question 9

Define adaptation

Answer 9

changes to the human system induced by exposure to an environmental stressor

Question 10

Define adaptation (genotypic)

Answer 10

genetically fixed condition of species or its evolution which favours survival in a particular total environment
-irreversible

Question 11

Define adaptation (phenotypic)

Answer 11

-acclimation/acclimatization
-changes that reduce the physiological/ emotional strain produced by stressful components of environment and occurring within the lifetime of the species
-reversible

Question 12

Define habituation

Answer 12

reduction of responses to repeated stimulation

Question 13

Define acclimation

Answer 13

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

Question 14

Define acclimitization

Answer 14

physiological/behavioural changes occurring within lifetime of an organism that reduce strain caused by stressful changes in natural climate (seasonal/ geographical)

Question 15

Define temperature

Answer 15

a number defined as the average kinetic energy of a system based on the random motion of atoms within an object

Question 16

Explain the zeroth law of thermodynamics

Answer 16

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

Question 17

Describe the first law of thermodynamics

Answer 17

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

Question 18

What is heat

Answer 18

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

Question 19

Define conduction

Answer 19

transfer of heat between surfaces that are in contact with each other

Question 20

What variables does heat flow depend on

Answer 20

-thermal conductivity of the object
-the size of the exposure area
-the difference in temp between objects
-the thickness of the object

Question 21

Thermal conductance is dependent on ____________

Answer 21

thickness

Question 22

Low thermal conductance value= _______

Answer 22

good resistor to heat
(there will be less transfer of heat between the objects)

Question 23

Define specific heat

Answer 23

the amount of heat required to raise the temp of an object by 1deg

Question 24

What does it mean if something has a high specific heat?

Answer 24

it is harder to change the temp/ requires a lot of energy to do so
(water and our bodies have high specific heat)

Question 25

Subcutaneous fat has a ______ specific heat and _______ thermal conductivity

Answer 25

high poor *due to this it plays a major role in heat gain and heat retention

Question 26

In hot weather, do we want clothes that are good thermal conductors or bad?

Answer 26

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)

Question 27

Define convection

Answer 27

heat transfer within and because of a fluid (gas or liquid) -heat rises, cold sinks -temp differences within fluids create currents

Question 28

What role does convection play in regards to the clothes you wear?

Answer 28

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

Question 29

Define radiation

Answer 29

transfer of heat by electromagnetic eaves -objects will absorb, reflect, store, and emit radiation

Question 30

_________ objects absorb light, __________ objects reflect light

Answer 30

black/dull (get more heat through radiation) light/reflective (don't gain much heat from radiation)

Question 31

Define emissivity

Answer 31

a measure of a material's radiating efficiency -higher number= better at radiating energy (human skin has good emissivity)

Question 32

Define thermoregulation

Answer 32

process of regulating body temp -occurs via basal metabolic heat production, food, and physical activity

Question 33

___________ is one of the primary homeostatically controlled processes in the human body

Answer 33

thermoregulation