VETS20019 Frontiers of Veterinary Science
overview - Key Concepts and Mechanisms
final exam 2026 prep University of Melbourne
Topic 1: Thermoregulation
Learning Outcomes
What constitutes an animal's environment?
What types of environment are there?
How do animals adapt to changes in environmental conditions?
How can changes in environmental conditions potentially lead to disease?
In what ways do veterinary professionals or researchers investigate the influence of
environment on animal health?
1. Explain how heat is lost from animals
2. Explain how heat is gained by animals
3. Describe the concepts of homeothermy and the thermoneutral zone
4. Provide examples of the adverse consequences of exposure to temperatures above and
below the thermoneutral zone
,Key definitions
Thermoregulation : Physiological + behavioural process to maintain a stable internal
temperature by regulating heat loss and gain
Homeotherm : animal able to maintain relatively stable internal core temperature range
internally in various environmental temperatures
Thermoregulatory set point = target temperature that the body's hypothalamus maintains for
optimal physiological function
Poikilotherm = (non-homeotherms)
Thermoneutral zone = range of ambient temperatures where temp regulation is attained without
regulatory changes in heat production or evaporative cooling
Cold stress = A physiological condition where heat loss exceeds heat production, leading to a
drop in core body temperature below the normal range.
Heat stress = A physiological condition where the body absorbs or retains more heat than it
can dissipate, causing a rise in core temperature and risk of hyperthermia.
Summary
Thermoregulation summary
- Concepts: homeothermy, thermoneutral zone, UCT, LCT
- Heat loss mechanisms
- Heat gain and conservation mechanisms
- Interpretation of elevated and decreased body temperatures
,- Effects of heat stress and cold stress
Key aspects + Ideas
Outputs (heat loss): Inputs (heat gain):
• Evaporation • Metabolic heat production
= liquid evaporates from body surface -> heat - Important for ruminants which produce
required for L to G state = transformational a lot of metabolic heat
heat absorbed from body surface = heat
energy removed away from body surface =
cooling the body
- Panting
• Infrared radiation from the animal • Infrared radiation from solid objects
= electromagnetic waves -> emission of heat
energy from body surface
- Emit and absorb radiant heat based
on environment
• Conduction into the in-contact environment • Conduction from the in-contact environment
= heat transfer through direct contact
between body surface and other object
-pigs wallow in mud
• Convection • Infrared radiation from the sun
= heat energy transfer via air currents= skin in
immediate contact with air -> air warmed by
skin via conduction -> warm air rises from
body -> cool air replaces= convection current
formed -> wind
-airflow
Dependent on skin contact
- Extra skin = inc convection = more
heat loss
, Homeotherm
- Regulate internal process controlling heat production and conservation
How?
Shivering Thermogenesis Non-Shivering Thermogenesis
Aspect Details Aspect Details
Definitio Involuntary, rapid rhythmic skeletal muscle Definitio Heat production without muscle activity
n contractions n
Mechani Reflex initiated by hypothalamus to cold Primary Brown adipose tissue (BAT)
sm Tissue
Function Increases metabolic heat production without
doing external work Mechan Hormone-driven fat metabolism; norepinephrine
ism stimulates UCP1 in mitochondria
Energy High – energy from muscle contractions is
Use converted into heat
Functio Converts chemical energy into heat instead of
Effective Quick response; effective in generating large n ATP
ness amounts of heat
Effectiv Sustained heat production especially important
Seen In All mammals including adult humans eness in neonates and small mammals
Seen In Newborns, hibernators; very limited in adult
humans
Piloerection (Goosebumps) Skin Vasoconstriction
Aspect Details Aspect Details
Definition Contraction of arrector pili muscles Definition Constriction of skin blood vessels to reduce
causing hair to stand on end blood flow to skin
Function Increases insulation by trapping warm air Function Keeps warm blood in core (away from
close to skin extremities) to reduce heat loss
Additional - Reduces heat loss by convection and
Effects radiation Effect Skin temperature drops; minimizes heat
- Mimics thick fur insulation in animals loss by radiation and conduction
Significance in Mostly vestigial due to sparse body hair
Humans Common Fingers, toes, ears, nose
Sites
Trigger Cold or emotional stimuli (fear, arousal) Affected
Controlled By Sympathetic nervous system
Summary Table
overview - Key Concepts and Mechanisms
final exam 2026 prep University of Melbourne
Topic 1: Thermoregulation
Learning Outcomes
What constitutes an animal's environment?
What types of environment are there?
How do animals adapt to changes in environmental conditions?
How can changes in environmental conditions potentially lead to disease?
In what ways do veterinary professionals or researchers investigate the influence of
environment on animal health?
1. Explain how heat is lost from animals
2. Explain how heat is gained by animals
3. Describe the concepts of homeothermy and the thermoneutral zone
4. Provide examples of the adverse consequences of exposure to temperatures above and
below the thermoneutral zone
,Key definitions
Thermoregulation : Physiological + behavioural process to maintain a stable internal
temperature by regulating heat loss and gain
Homeotherm : animal able to maintain relatively stable internal core temperature range
internally in various environmental temperatures
Thermoregulatory set point = target temperature that the body's hypothalamus maintains for
optimal physiological function
Poikilotherm = (non-homeotherms)
Thermoneutral zone = range of ambient temperatures where temp regulation is attained without
regulatory changes in heat production or evaporative cooling
Cold stress = A physiological condition where heat loss exceeds heat production, leading to a
drop in core body temperature below the normal range.
Heat stress = A physiological condition where the body absorbs or retains more heat than it
can dissipate, causing a rise in core temperature and risk of hyperthermia.
Summary
Thermoregulation summary
- Concepts: homeothermy, thermoneutral zone, UCT, LCT
- Heat loss mechanisms
- Heat gain and conservation mechanisms
- Interpretation of elevated and decreased body temperatures
,- Effects of heat stress and cold stress
Key aspects + Ideas
Outputs (heat loss): Inputs (heat gain):
• Evaporation • Metabolic heat production
= liquid evaporates from body surface -> heat - Important for ruminants which produce
required for L to G state = transformational a lot of metabolic heat
heat absorbed from body surface = heat
energy removed away from body surface =
cooling the body
- Panting
• Infrared radiation from the animal • Infrared radiation from solid objects
= electromagnetic waves -> emission of heat
energy from body surface
- Emit and absorb radiant heat based
on environment
• Conduction into the in-contact environment • Conduction from the in-contact environment
= heat transfer through direct contact
between body surface and other object
-pigs wallow in mud
• Convection • Infrared radiation from the sun
= heat energy transfer via air currents= skin in
immediate contact with air -> air warmed by
skin via conduction -> warm air rises from
body -> cool air replaces= convection current
formed -> wind
-airflow
Dependent on skin contact
- Extra skin = inc convection = more
heat loss
, Homeotherm
- Regulate internal process controlling heat production and conservation
How?
Shivering Thermogenesis Non-Shivering Thermogenesis
Aspect Details Aspect Details
Definitio Involuntary, rapid rhythmic skeletal muscle Definitio Heat production without muscle activity
n contractions n
Mechani Reflex initiated by hypothalamus to cold Primary Brown adipose tissue (BAT)
sm Tissue
Function Increases metabolic heat production without
doing external work Mechan Hormone-driven fat metabolism; norepinephrine
ism stimulates UCP1 in mitochondria
Energy High – energy from muscle contractions is
Use converted into heat
Functio Converts chemical energy into heat instead of
Effective Quick response; effective in generating large n ATP
ness amounts of heat
Effectiv Sustained heat production especially important
Seen In All mammals including adult humans eness in neonates and small mammals
Seen In Newborns, hibernators; very limited in adult
humans
Piloerection (Goosebumps) Skin Vasoconstriction
Aspect Details Aspect Details
Definition Contraction of arrector pili muscles Definition Constriction of skin blood vessels to reduce
causing hair to stand on end blood flow to skin
Function Increases insulation by trapping warm air Function Keeps warm blood in core (away from
close to skin extremities) to reduce heat loss
Additional - Reduces heat loss by convection and
Effects radiation Effect Skin temperature drops; minimizes heat
- Mimics thick fur insulation in animals loss by radiation and conduction
Significance in Mostly vestigial due to sparse body hair
Humans Common Fingers, toes, ears, nose
Sites
Trigger Cold or emotional stimuli (fear, arousal) Affected
Controlled By Sympathetic nervous system
Summary Table
