13.11.23 - Communication and Homeostasis: Thermoregulation and Homeostasis Flashcards
What is thermoregulation?
Maintenance of relatively CONSTANT core body temperature
What is homeostasis?
Maintenance of constant INTERNAL conditions in response to INTERNAL or EXTERNAL changes
What is negative feedback?
Keeps certain PHYSIOLOGICAL factors within **CERTAIN LIMITS **
Give an example of a physiological factor
Blood GLUCOSE concentration
How does negative feedback work?
- Change in INTERNAL environment detected
- Change SIGNALLED to other cells
- Cells REVERSE these changes
How does positive feedback work?
- Change in INTERNAL environment detected
- Change SIGNALLED to other cells
- Cells respond to INCREASE change
Give an example of positive feedback
- When temperature below certain core body temperature, enzymes less active
- Less activity means less EXOTHERMIC reactions
- Less heat released
- Body temperature continues to DECREASE
What is the role of the hypothalamus?
Constantly MONITORS blood flowing through it
What is our core body temperature?
37°C
What does our core body temperature depend on?
People, level of ACTIVITY, time of day and STAGE of menstrual cycle
What part of the body first detects temperature change?
Skin
What happens when you first feel cold?
Skin receptors respond and CORE body temperature remains UNCHANGED
What are ectotherms?
Animals whose core body temperature DEPENDENT on temperature of environment
What are endotherms?
Animals whose core body temperature remains CONSTANT regardless temperature of environment
Give three examples of ectotherms
Fish, amphibians and reptiles
