chapt 29 Flashcards
homeostasis
maintain intetnal environment, including temperature, pH, ion concentrations, O2 and CO2 levels, snf levels of fuel molecules such ad glucose
interstitial fluid
between the cells of body; majority of extracellular fluid; allows the exchange of materials/nutrients between cells; dumping site for waste in cells (poisons it)
epithelial tissues
sheets that are densely packed; cover inner and outer body surfaces; secrete substances (like hormones or sweat), serve as selective barriers, transport, and sense
connective tissue
dispersed populations in extracellular matrix
composition and properties differ between tissues. ex: a matrix of bone gives rigid structural stength
nervous tissues
consists of neurons (electrical signals/nerve impulses around body) and glial cells (chem signals and support neurons)
muscle tissue
most of body mass in vertebrates; elongated cells that can contract, skeletal muscle vs heart muscle vs smooth muscle
set point
speed at which you control your body to go
feedback info
information that gets sent back about set pt
error signal
diff between set pt and feedback info
regulatory systems
obtain, process, and integrate feedback info and then issue commands to effectors
negative feedback
most common; used to counteract influence created by error signal
negates factors that push away from set pt (decresdes deviation from set pt)
positive feedback
amplifies a response (increases deviation from set pt)
feedforward information
changes set pt
like if you suddenly see a deer in the road and you slow down
temperature of cells
cells cool at < 0C (and ice crystals damage structure)
their proteins denature at > 40C
0-40C WITH THE MOST VARIATION
humans are actually 35C-40*C
ectoderms
temp of fish, amphibian, or reptile relies on temp of environment
endotherm
temp of birds and mammals maintain high and constant body temperatures over wide range range of temp
*can generate internal heat metabolically
basal metabolic rate (BMR)
metabolic rate is at min that still allows for homeostasis in resting animal
thermoneutral zone (TNZ)
range where the metabolic rate remains low and constant
metabolism
conversion of chem bond energy to atp, and the use of atp to make heat
radiation
warmth goes to cold objects
incoming: absorbed heat
outgoing: emitted heat
convection
heat transfers to surrounding medium
conduction
direct heat transfer when objects touch
evaporation
heat transfere away from surface
lower critical temperature
when temp is lower than an endotherm’s rhermoneutral zone and the animal must increase metabolism
(like by shivering thermogenesis)
brown fat
used as animals hiberate so that tissues can burn fuel without producing
concurrent heat exchange
heat exchange between blood vessels carrying blood in opp directions
happens in fish conserving metabolic heat because it allows the fish to have a higher internal body temp than the water (it can be faster and stronger)
behavioral thermoregulation
ectotherms can regulate body temp with behavior, like if a lizard starts catching sunlight in early morning
hypothalamus
thermostat in brain: causes you to seek cooler/warmer environment
stimulates changes in body such as sweating and dilating/constricting blood vessels
if hypothalamic set pt rises, fever
daily torpor
lowering body temp at parts of day ro conserve energy
lasts multiple days in hibernation
