chapter one

the science or doctrine that explains the universe in terms of ends or final cause, why events happen

explains phenomena of nature on principles of physical processes (sequence of events), how events happen

study of mechanisms by which living organisms function

stuff inside the cell (cytoplasm)

buffer between cells and outside world (outside cells but inside body), external environment of the body

interstitial fluid, blood plasma

materials moving between cells and ECF must cross the cell membrane, separates cells from ECF

maintenance of a relatively stable internal environment

concentration of nutrients, gases, wastes, water & salts, pH, temperature

is the balance between inputs & outputs

is not maintained (body temperature fluctuates)

existing body load + intake or metabolic production - excretion or metabolic removal

strive to maintain a near constant set point, molecular motion flucuates

changes move the variable back towards the initial set point

can be physiologically reset (raised or lowered), they can be changed

because not everything can be homeostatically maintained at the same time

study of diseased conditions

changes internally, haven’t eaten in 5 days means you lack nutrients coming in

changes outside the body, hot day/environment, walk into a cold room

local control & feedback (response) loops

stimulus & control occur within the same area, isolated changes within a tissue, no response loop is utilized

slamming your finger in the door. stimulus and response at the finger

stimulus & response are not necessarily together, long distance communication & coordination

sensor in brain trying to regulate body temp by sweating, stimulus in brain, response all over skin connected by nerves & hormones