Concept 32.3: Feedback Control

Why would managing an animal’s internal environment be challenging?

Due to environmental fluctuations

What are the two methods animals use to manage their internal environment?

• Regulating

• Conforming

What is regulating?

Involves maintaining a stable internal environment despite external changes

What is conforming?

Means allowing the internal environment to change in accordance with external conditions

What do regulators use internal mechanisms for?

To maintain stable internal conditions despite external fluctuations

Why do conformers allow their internal conditions to change?

In response to external environmental changes

What is an example of a temperature regulator?

The river otter; maintains a constant body temperature regardless of the water temperature

What is an example of a temperature conformer?

Largemouth bass; with its body temperature changing to match the water temperature

What is homeostasis?

Maintenance of a relatively constant internal environment despite significant external changes

Name three physical and chemical properties animals maintain homeostasis for.

• Body temperature

• Blood pH

• Blood glucose concentration

What is an nonliving example of a control system for achieving a steady state?

Thermostat regulating room temperature

What is thermoregulation?

The process by which animals maintain their body temperature within a set range to ensure efficient enzymatic reactions and proper cellular function

What are endotherms vs ectotherms?

• Endotherms: Generate heat through metabolism (e.g., mammals, birds)

• Ectotherms: Gain heat from external sources (e.g., amphibians, reptiles, invertebrates)

Describe the abilities of endotherms vs ectotherms.

• Endotherms: can maintain stable body temperatures despite environmental changes

• Ectotherms: adjust body temperature behaviorally, such as basking in the sun or seeking shade

Name the four mechanisms of heat exchange.

• Radiation

• Convection

• Conduction

• Evaporation

What is radiation?

Emission of electromagnetic waves

What is convection?

Transfer of heat by air or liquid movement

What is conduction?

Direct transfer of heat between objects in contact

What is evaporation?

Heat loss through the conversion of liquid to gas