Thermoregulation

Question 1

what does a climate include?

Answer 1

• temp
• sunlight
• wind
• precipitation
• humidity

Question 2

any behavioural or physiological characteristics that help survive in own environment

Answer 2

adaptation

Question 3

structural changes that give an animal a greater change of survival in it habitat

Answer 3

morphological adaptations

Question 4

physical features of the animals which help them to survive in a specific environment

Answer 4

anatomical adaptations

Question 5

environmental factors that influence animals

Answer 5

• ambient temp
• relative humidity
• radiation (solar)
• atmospheric pressure
• wind velocity

Question 6

why is heat stress accumulative?

Answer 6

if an animal isn’t in prime health, it can’t effectively adapt to changing temps

Question 7

core body temp body thermoregulation is an interaction between…

Answer 7

core and surface temperatures
- being too high can cause cellular breakdown

Question 8

mean body core temperature is calculated by

Answer 8

weighted mean between core & skin temp

Question 9

1st law of thermodynamics

Answer 9

all energy in the world has already existed

Question 10

2nd law of thermodynamics

Answer 10

all order goes towards disorder, there is less organised energy today than yesterday
- results in ultimate release of energy in its lowest form = heat

Question 11

endotherms

Answer 11

• ‘warm’ blooded
• CBT is stable & determined by internal sources
• thermoregulation

Question 12

advantages of endotherms

Answer 12

• continuation of temp-dependant reactions
• continuation of enzyme controlled reactions

Question 13

disadvantages of endotherms

Answer 13

• requires regulation
• needs energy, body modification
• moderate deviations from normal CBT can have serious effects

Question 14

ectotherms

Answer 14

• CBT derived from external sources of heat
• CBT fluctuates w/ environmental temp
• ET rapidly effects function
• May still be modification

Question 15

advantages of ectotherms

Answer 15

• fluctuates w/ external temps
• use less food in respiration
• survive w/ less food for longer periods
• more energy to be used for growth

Question 16

disadvantages of ectotherms

Answer 16

• less active in cooler temps
• not capable of activity during climate extremes
• need sufficient energy stores
• can’t increase respiration rates to generate internal heat

Question 17

regulation mechanisms

Answer 17

• balance between heat production & heat loss
• sensors detect temp
• feedback via CNS
• responses both voluntary & involuntary

Question 18

ability to regulate temp depends on

Answer 18

• ability to produce heat at low ETs
• ability to lose heat at high ETs

Question 19

the range of ambient temperatures where the body can maintain its core temp solely through regulating dry heat loss

Answer 19

thermal neutral zone

Question 20

requires an organism to increase its metabolic rate to meet the environmental demands for heat
- organism reaches LCZ when ambient temp decreases

Answer 20

lower critical zone

Question 21

• realised when evaporative heat loss for cooling occurs due to temps over TNZ

Answer 21

upper critical zone

Question 22

energy/heat storage

Answer 22

temporary storage of heat
- production greater than loss

Question 23

channels of heat exchange

Answer 23

• conduction = through medium
• convection = through fluid
• radiation = as waves
• evaporation = usually only heat loss

Question 24

sources of heat production

Answer 24

• basal metabolic rate
• productive processes = pregnancy, growth
• heat increment of feeding
• shivering

Question 25

processes that inc/dec rate of energy loss from body

Answer 25

- vasodilation/constriction - pilo-erection - sweating - panting

Question 26

factors effecting rates of heat production

Answer 26

- environmental temp - body size - plane of nutrition - increment of feeding - rumen = heat generated as byproduct of fermentation - non-shivering thermogenesis

Question 27

factors effecting heat loss

Answer 27

- evaporation - sweating, panting - radiation - convection - conduction - insulation

Question 28

cattle are cold tolerant due to

Answer 28

- relatively large size - small SA/V ratio - loses heat more slowly - coat = insulation - rumination produces heat

Question 29

cattle are heat tolerant due to

Answer 29

- sweating profusely - panting effectively - coat can reflect radiation

Question 30

uk requirements for keeping cattle

Answer 30

- optimum temp 10-15oC - dry, drought-free condition - increasing awareness of heat stress

Question 31

sheep are well adapted to the cold by

Answer 31

- insulating fleece - internal fat insulation - effective vasoconstriction - high metabolic rate in cold - lambs have brown adipose tissue at birth

Question 32

sheep are well-adapted to heat by

Answer 32

- fleece reflects radiation - effective panting

Question 33

uk requirements for keeping sheep

Answer 33

- comfortable outdoors for most of year - beware weather conditions at shearing - not suited to wet conditions

Question 34

why pigs become heat intolerant

Answer 34

- piglets are relatively small - high SA/V ratio - little adipose tissue

Question 35

uk requirements for keeping pigs

Answer 35

reduce heat loss & increase supply - insulate building - heat lamps - electric heater - encourage huddling - beware of draughts