Homeostasis and Behavior Flashcards
what is homeostasis?
maintenance of an internal balance regardless of external environment
do all animals have to eat?
yes
do all animals have to drink?
all animals need water but not necessarily from drinking
how do we define obesity
BMI of 30 or higher
what are examples of homeostasis factors
temperature
blood pH
glucose concentration
salinity
what do most cellular processes require?
specific internal conditions
what are some examples of specific internal conditions?
metabolic demands
enzymatic reactions
membrane transport
maintaining homeostasis requires what?
work
work requires what?
energy
maintaining homeostasis increases ….?
fitness
what can lead to higher fitness
changing homeostatic conditions
give an example of what lizards do to change their homeostatic conditions to lead to higher fitness
they elevate their body temperature when facing infection
what are examples of internal stimuli
hormones and genetics
what are examples of external stimuli
environmental cues
by maintaining certain conditions through homeostasis it makes things what?
more predictable
are humans endotherms?
yes
are animals mostly water or salt
water
adapting to land required managing what
water retention and loss
maintaining water balance relies on
osmosis
what causes thirst
changes in osmotic conditions
what is thirst
motivation to seek and ingest water
can thirst be measured directly
no
what are the two types of thirst
osmotic “intracellular thirst”
hypovolemic “extracellular thirst”
what is thirst mediated indirectly by
AVP via salt balance
what does AVP cause
water retention by kidneys
after max water retention achieved by kidneys what is triggered
thirst
what can lead to the inability to produce AVP
genetic mutations
you lose copious amounts of water through urination so what do you do to compensate
consume water
what reduces water intake
AVP injection
AVP release is triggered by?
osmoreceptors in the hypothalamus
(paraventricular nuclei and supraoptic nuclei)
what else is thirst also mediated by?
renin-angiotensin-aldosterone system (RAAS)
what detects drop in blood pressure and or volume
baroreceptors in blood vessels
baroreceptors trigger what when they detect the drop in blood pressure
release of renin
renin causes release of
angiotenin
angiotensin triggers release of
aldosterone in adrenal glands
aldosterone triggers what
drinking behavior
what do animals need to maintain homeostasis and perform necessary functions of life
energy
give examples how animals use their energy to maintain homeostasis
- growth, repair and development
- reproduction/ parental care
- activity/ behavior
where does energy come from
stored chemical energy in food
food=
macronutrients (carbs, proteins, and lipids)
macronutrients can be broken down into what
fuels
fuels are oxidized to form what?
ATP
animals need a continous supply of what for cellular work
energy
many animals do no continuously eat; this requires what
energy balance
metabolic fuels provided from digested food
fed state
metabolic fuels provided from the breakdown of stored food
fasting state
hormones associated with fed state metabolism
insulin
glucagon
leptin
ghrelin
what are neuropeptides associated with fed state metabolism
proopiomelanocortin
cocaine and amphetamine regulated transcript
neuropeptide Y
agouti-related protein
hormones associated with fasting state metabolism
insulin
glucogon
leptin
ghrelin
neuropeptides associated with fasting state metabolism
proopiomelanocortin
coacine and amphetamine regulated transcrippt
neuropeptide Y
agouti-releted protein
blood glucose concentration is main signaling controlling food intake
glucostatic hypothesis
