15.2 thermoregulation

Core Body Temperature

Core Body Temperature

process of maintaining relatively constant internal temp crucial for optimum enzyme activity

Ectotherms

animals that use surroundings to regulate body temp ex. reptiles, fish.

Endotherms

animals that rely on metabolic processes to control body temp ex. mammals, birds.

Behavioral Temperature Control

Ectotherms can only regulate body temp through behavioral changes ex. basking in sun, seeking shade

Internal Temperature Variation

ectotherms' internal temp influenced by environmental temps, while endotherms maintain stable internal temperature

Activity Level in Ectotherms

Ectotherms' activity increases with warmer temperatures and decreases when it's cooler.

Metabolic Rate in Ectotherms

ectotherms have variable metabolic rate + produce minimal heat on their own

Endothermy

ability of endotherms ex. mammals + birds, to maintain stable internal temp through physiological mechanisms

Thermoregulation in Endotherms

endothermic animals detect external temps via thermoreceptors (communicate w hypothalamus to initiate physiological responses)

Hypothalamus Role

hypothalamus regulates body temp by monitoring blood temp + initiating homeostatic responses

Advantages of Endothermy

Endotherms can remain active in cold temperatures and colonize colder regions with less competition.

Disadvantages of Endothermy

maintaining temp in cold environments requires significant energy intake + more food.

Thermoregulation Cycle

process involves detecting temperature changes, sending info to hypothalamus + producing responses to adjust body temp

Warming Up Mechanisms

endotherms raise body temp: increasing respiration rate, shivering + seeking shelter.

Cooling Down Mechanisms

lower body temp: endotherms reduce movement, sweat + relax piloerector muscles.

Conduction

A method of heat transfer where ectotherms may lie on cold ground or stay in cold water.

Convection

ectotherms move to lower ground/cold water or air currents to regulate temp

Radiation

ectotherms find shade/enter burrows to avoid excessive heat

Ectothermy

ectotherms ex. reptiles, amphibians, cannot maintain body temp efficiently + rely on external temperatures.

Advantages of Ectothermy

Ectotherms use less food for respiration and require less food overall, allowing more energy for growth.

Disadvantages of Ectothermy

ectotherms are less active in cool temps + must warm up before becoming active, increasing predation risk.

Behavioral Changes in Ectotherms

Ectotherms primarily use behavioral changes to regulate body temperature by moving between warmer and cooler areas.

Hypothalamus in Thermoregulation

hypothalamus acts as brain's thermostat, coordinating heat loss/gain to maintain optimal body temp

Heat Loss and Gain Centers

hypothalamus has 2 control centers that respond to changes in blood temp to regulate heat loss or gain

Information Processing in Hypothalamus

hypothalamus collects + processes info abt core + surface body temp to detect deviations/restore ideal temp