BIO 112 Homeostasis

regulators

______ use internal mechanisms to control internal change in the face of external fluctuations.

conformers

______ allow internal conditions to change in accordance with external fluctuations.

homeostasis

ability to main physiologically favorable internal environment

negative feedback

control mechanism that reduces the stimulus and brings back to set point

positive feedback

control mechanism that amplifies the stimulus to drive processes to completion.

stimulus

physical condition of the body being monitored

sensor

the part of the body that monitors the conditionc

omparator

the parts of the body that compare the current condition to the set point and issues the command for a change in the activity.

effector

activity that acts to bring stimulus back to set point

thermoregulation

maintaining body temperature within a tolerable range

enzymes

____ catalyze all your internal (metabolic) reactions.

proteins

enzymes are ____?

they denature, lose shape, and cannot work

what happens to proteins at high temperatures?

move slow and do not interact as much, do not work sometimes

what do proteins and molecules do at low temperatures?

endotherm

type of organism where body temperature is regulated by metabolism

ectotherm

type of

generate body heat through metabolism and have mechanisms to regulate, more activity in non-optimal temperature, high levels of aerobic metabolism, perform vigorous activity for longer periods than ectotherms

advantages of endothermy

energetically expensive, consume more food

disadvantages of endothermy

vasodilation

expansion of the diameter of superficial blood vessels increasing blood flow and heat to skin

vasoconstriction

constriction of the diameter of superficial blood vessels decreasing blood flow and heat to skin

countercurrent heat exchange

arteries carrying warm blood are in close contacts with veins conveying cool blood back toward the trunk

evaporation across the skin

terrestrial animals lose water by ____?

thermogenesis

varying heat production to match changing rates of heat loss

torpor

physiological state in which activity is low and metabolism decreases; can be short or long term

hibernation

long-term torpor that evolved as an adaptation to winter cold and food scarcity

estivation

summer torpor

osmoregulation

balancing water gain and loss

osmosis

occurs whenever 2 solutions separated by a membrane differ in osmolarityo

osmolarity

moles of solute per liter of solution

isosmotic

if two solutions separated by a selectively permeably membrane have the same osmolarity they are ________?

hyperosmotic

when two solutions differ in osmolarity, the one with a higher concentration of solutes is _____?

hypoosmotic

when two solutions differ in osmolarity, the one with a lower concentration of solutes is _____?

high to low

net movement of water is from ____ to _____?