Metabolism And Energetics Flashcards
What happens when an animals body temperature is hotter than the outside environment temperature?
The heat exits the anima to colder temp. Via gradientl; cooling the animal
What happens when an animal’s body temperature is lower than the outside environment temperature?
The heat from the outside environment goes into the animal’s cooler body temp. via gradient; animal gets hotter
Thermoregulation
Maintaining a certain temp.; if exceed limit -> denaturing of enzymes
Where does heat production occur?
Heat is produced in organs or muscles like brain and liver; calories are being burned=heat production
Where does heat loss occur?
In extremities like feet, fingers, nose, and ears
Why is the core cooler compared to the extremities?
Heat is being sent out in the extremities; core is cool because even though it produces heat it retains the heat via insulation
Insulation
Keeping warm; fur and feathers increase boundary layer
Boundary layer
Region near surface where fluid velocity drops to zero
How do fur and feathers help w/ increasing the boundary layer?
They trap air causing the air to not move, like “wearing a jacket”
Blubber
Internal insulator; white fat under skin used for storage and prevents heat loss to ocean
Countercurrent exchange
Minimizes heat loss in extremities via gradients
What is an example of countercurrent exchange?
A seagull is standing in cool water. It’s warmer blood travels down to its feet (an extremity) and gets colder. In the feet, the there are two vessels (artery and vein) next to each other traveling in different directions and they meet in the feet arranged in a web. As the blood travels up back to the core, the heat from the core that is traveling down transfers some heat to the colder blood.
Differences between countercurrent and concurrent flow.
Countercurrent: blood flows in opposite directions and vessels are next to each other
Concurrent: blood flows in same directions and vessels are not flowing near each other
Thermogenesis
Keeping warm; burning calories; Ex: shivering and brown fat
Shivering
Spend energy and let muscles contract to burn calories to heat up the body
Brown fat
Stored in the body just for generating heat; bears have mostly brown fat; heat energy from brown fat does not go to other organs or muscles only locally
Behaviors for warmth
Decomposition and huddling
Decomposition
Birds(?) bring dead corpses in a ring to heat their chicks(?) up
Huddling
Stay close together keeping warm and reducing airflow
Vascularization
Keeping cool; anything w/ vessels
Example of vascularization.
An elephant carries warmer blood to ear and it flaps ears to cool itself; veins are arranged randomly in the ear (an example of cocurrent blood flow)
Evaporative cooling
Transferring heat energy to water where it can evaporate to the atmosphere; splashing oneself w/ water, licking oneself, panting, sweating
Behaviors for staying cool
Nocturnality, burrowing
Nocturnality
Only appear at night when it’s cool
Burrowing
Digging underground to stay in the cooler dirt compared to the hot surfacs
Basal Metabolic Rate (BMR)
Metabolic rate at rest
Absolute metabolism
BMR vs Body Mass; the bigger the animal the more calories burned/energy needed; Elephants have the highest
Mass specific metabolism
BMR per kg body mass vs. Body mass; how much energy needed per gram to maintain temp.; smaller animal needs to eat more per gram to conserve heat; bigger animals do not lose heat as fast due to higher volume to SA ratio; Shrews (tiny) have the highest
Which of the following statements abt animal evolution is TRUE?
Complex organ systems evolve only in large animals
Metazoans and chanoagellates share a common ancestor
Integumentary structures are homologous
Shivering thermogenesis warms an animal by increasing its boundary layer
Metazoans and chanoflagellates share a common ancestor
Torpor
Occurs when cold; hibernation to save energy
Estivation
When hot; hibernation underground
Would torpor benefit large or small animals more?
Benefit small because it takes a lot of energy to warm up the body for large animals
