Homeostasis - Thermoregulation Flashcards
What is thermoregulation and why is it important?
- The maintenance of body temps within a range that enables cells to function effectively
- Enzymes have optimal temps, high temps can denature proteins
Homeotherm vs Poikilotherm
Homeotherm: animal that maintains stable body temp regardless of temp of external environment
Poikilotherm: animal whose body temp varies + often matches the temp of external environment
Endotherm vs Ectotherm
Endotherm: animal that maintains body temp by internal mechanisms
Ectotherm: animal that maintains body temp by absorbing thermal energy from environment
What are the sensors, control centre, and effectors of thermoregulation in humans?
- Sensors: central + peripheral nervous systems
- Control centre: hypothalamus
- Effectors: muscles, blood vessels, sweat glands
What is the body’s response to heat stress?
- Blood vessels in skin dilate, increasing blood flow to skin -> increases heat loss from blood
- Sweat glands produce perspiration which evaporates, taking heat w/ it
- Negative feedback: responses lower body temp to normal range
What is the body’s response to cold stress?
- Blood vessels in skin constrict
- Skeletal muscle contracts rapidly (shivering), increasing metabolism + production of heat
- Smooth muscle around hair follicles contract, producing goosebumps
- Negative feedback: responses raise body temp to normal range
What is brown fat and why is important?
- Prolonged exposure to cold stress can create hormonal associated w/ brown fat
- It insulates + generates heat
- Converts chemical energy into heat
- Especially important in newborns since they cannot shiver
- Babies have small amounts of brown fat in their neck, armpits, + near kidneys
What is hypothermia and its symptoms?
Occurs when core body temp drops below 35 degrees celsius
Symptoms:
- Look pale
- Cyanosis: blue lips + fingers
- Appear disoriented + lethargic
- Slow pulse + breathing rate
- Shivering stops in late stage
