Card Set Information
Lecture 1- Form & Function
Miscommunications between pancreas and glucose storage tissues (liver and muscles)
Lou Gehrig’s Disease (ALS)
Lack of communication between brain and muscles
uses internal control mechanisms to moderate internal change in the face of external/environmental fluctuation
Allows its internal condition to vary with certain external changes
“steady state,” internal balance regardless of external conditions
Mechanism that helps return a variable to its normal range, helps maintain homeostasis
when homeostasis adjusts to changes in the external environment (climbing mountains)
process by which animals maintain an internal temperature within a tolerable range
generate heat by metabolism (birds, mammals)
gain heat from external sources
things that help reduce heat flow between an animal and its environment (skin, feathers, fur, blubber)
How does signaling by hormones work? Which system is involved?
endocrine cells release hormones into the bloodstream, which ravel thought the body, only the cells with a specific receptor will be able to recognize the signal
How does neuronal signaling work?
stimulus travels down axon and stimulates a specific cell (can be a neuron or another cell)
Main difference between hormonal signaling and neuronal signaling?
There are fewer cells involved in neuronal (only 1)
Hormonal affects more than one area/organ while neuronal is localized to a specific area/cell
widening of blood vessels near the skin, which causes blood flow to increase
reducing blood flow and heat transfer by decreasing diameter of blood vessels near skin
Vasodilation vs. Vasoconstriction: want to cool down
want to get as much blood to get close to the surface of the skin as possible
vasodilation causes capillaries to circulate blood
skin gets warmer
results in loss of heat
Vasodilation vs. Vasoconstriction: want to warm up
blood is prevented from flowing near surface of skin
don’t lose as much heat because skin gets colder
Two alternative ways to cool down?
: moistens the skin, when the sweat evaporates, the skin cools down
: increases cooling effect in birds and mammals, releases hot air and brings cold air in
What role does hypothalamus play? (2 things)
Serves as thermostat for the body
Activates cooling mechanisms in the body
Why is it a bad idea to cool down brain quickly if you are hot?
If your body is really hot, cooling the hypothalamus too fast will make it think that the body is cold, and warming up response will be activated instead
Responses to body temperature decreasing?
Responses to body temperature increasing?
Overall flow and transformation of energy in an animal
Amount of energy an animal uses in a unit of time
Metabolic rate can be determined by:
an animals heat loss
amount of oxygen consumed or carbon dioxide produced
Basal Metabolic Rate
metabolic rate of an endotherm at rest at a “comfortable” temperature
Standard Metabolic Rate
metabolic rate of an ectotherm at rest at a specific temperature
As body mass increases, BMR (increases or decreases)?
Mouse vs. Elephant — which has higher BMR?
mouse does because it has a higher metabolic rate per gram than the elephant does
Mouse consumes more energy per gram of body than elephant