Kategóriák: Minden - radiation - conduction - metabolism - evaporation

a Nurul Shazwa 3 éve

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THERMAL PHYSIOLOGY

The study of thermal physiology encompasses various mechanisms and responses that organisms employ to maintain their body temperature within optimal ranges. Key strategies involve both physiological and behavioral adaptations.

THERMAL PHYSIOLOGY

THERMAL PHYSIOLOGY

Heat production may happen as a by-product of metabolic processes.

Thermogenesis
An endothermic organism struggles in face of a colder-than-desirable ambient.
Thermal energy will not be transferred when there is thermal equilibrium.
The inefficient part of molecular transformations that causes part of the energy not to be used for work, but instead, lost as heat.

Thermoregulation

Physiological response
Countercurrent Exchange
Circulating Adaptation

Vasocontriction

Vasolidation

Non-shivering

Metabolism --> increase heat production.

Shivering

Muscle contraction --> increase heat production.

Sweating
Insulation
Behavioral response
Surface area/ volume

Thermal strategies

Homeotherm
Maintain relatively constant internal environmental.
Poikilotherm
Body temperature varies directly with environmental temperature.
Endotherm
Rely heavily on metabolic energy.
Ectotherm
Rely mainly on external energy source.

To investigate the biological implications of temperature to the function of living organisms.

Thermal zone

Thermoneutral zone
Metabolic rate is minimal (basal metabolic rate).
Lower critical zone
Metabolic rate ↑ to induced heat production. (Hyphothermia)
Upper critical zone
Metabolic rate ↑ to induced a physiological response to prevent overheating. (Hyperthermia)

Heat fluxes (Body Temperature, TB)

Evaporation
Magnitude of heat loss depend on volume of H2O and its heat of vaporization.
Water molecules absorb thermal energy from an object when making the transition from liquid to vapor.
Radiation
All bodies, including mammals, emit heat by radiation.
Transfer of thermal energy in the form of light waves, as exemplified by the heat we receive from the sun.
Convection
Exchanged depend on: • thermal gradient • rate of flow the fluid • the conductivity of the fluid
The heat is being carried from one point to another by a moving substance.
Conduction
Rate depend on: • area of physical contact • different temperature • thermal conductive properties
Heat flows from a region of ↑ temperature to a region of lower temperature.
Direct transfer of heat between two substances in contact with each other.
Metabolism
Main source of thermal energy in the heat balance equation.

This includes adaptations in face of environmental challenges.