Convection – Vocabulary Flashcards (Heat Loss/Gain)

Vocabulary terms and definitions covering convection, heat transfer, and thermoregulatory adaptations from the lecture notes.

Convection

Movement of heat between a body and a moving fluid (e.g., air); can be natural/passive or forced and often important in energy balance.

Natural Convection

Fluid motion caused by buoyancy from temperature differences, without external forcing.

Forced Convection

Fluid motion driven by external means (e.g., fans, pumps, or body movement).

Boundary Layer

Thin layer of fluid near the surface where most heat exchange occurs between surface and environment.

Conduction

Heat transfer through direct contact; rate depends on area, temperature difference, and material properties.

Radiation

Heat transfer by electromagnetic waves; depends on surface area and temperature.

Evaporation

Heat loss via phase change of water to vapor on the skin; requires heat extraction from the body.

Panting

Cooling via rapid breathing; increases surface area (tongue) for evaporative cooling.

Rete mirabile

A counter-current heat exchanger in animals that enables efficient heat transfer for thermoregulation.

Counter-current heat exchange

Arrangement where arteries and veins run in opposite directions to exchange heat, aiding cooling or heat retention.

Sinus evaporation

Evaporation from nasal/sinus regions contributing to cooling.

Piloerection

Hair standing up to trap an insulating air layer, reducing convective heat loss.

Tropically adapted cattle (Senepol)

Breed with traits (short/sparse/unmedullated hair, pigmented skin, short ears, mobile tail, wrinkled skin) that enhance heat loss.

Surface Area to Volume ratio and heat loss

Higher SA:V leads to faster heat loss; small animals lose heat more quickly and may eat more relative to body weight.

Aquatic convection

In water, convection is typically faster, significantly impacting heat loss in aquatic animals.