BIOL 371 Topic 4 Animals (I made these)

homeostasis is the maintenance of a stable ______ environment

internal

homeostasis is regulated by ____ ____ loops

negative feedback

describe the flow of negative feedback loops

change in a physiological variable → receptor detects change → integrator processes information → effector produces response

t/f cell location changes how homeostasis occurs

true

t/f cells of exchange surfaces can be either dead or alive

false; must be alive to properly maintain homeostasis

regulation of solute content and volume in extracellular fluid is an example of ______ regulating internal environments

homeostasis

what is osmoregulation

regulation of internal osmotic environment (water/salt/waste)

what is ficks law

the rate in which particles diffuse across a concentration gradient proportional to surface area

what mechanism allows bulk flow to occur

hydrostatic pressure (mechanical)

what is established after letting diffusion occur in a closed space

equilibrium

t/f osmoles are the total number of dissolved particles of solvent per kg of solute

false; solute per kg of solvent

what is osmolality ad what is it measured in

osmotic concentration of a solution'; measured in osmoles

t/f hypoosmotic things have a higher osmolality than its reference solution

false; lower osmolality

what is the difference between isoosmotic and hyperosmotic

iso: same osmolality as solution

hyper: higher osmolality than solution

what is osmosis

tendancy of water to diffuse across a selectively permeable membrane from area with lower conc

t/f osmosis involves movement of solutes across membrane

false; movement of water

what substance has the highest osmotic potential and what is that potential

pure water; zero

t/f less solute = higher (more positive) osmotic potential

true; more solute = lower (more negative) potential

in osmosis water moves from ____ negative to _____ negative volumes

less; more

what happens when pressure potential is added to the side with a lower osmotic potential

flow across membrane decreased, reversed or stopped

water moves from areas of ____ water potential to ___ water potential

high; low

what is the difference in significance between animal and plant cells

animal: cell shrinks or swells

plants: swells based on turgor pressure

how are fluids transported in animals and what is that mechanism reliant on

bulk flow; hydrostatic pressure

t/f bulk flow affects water and solute exchange in open circulatory systems

false; closed systems

describe how pressure potential impacts water/solute movement in capillaries in relation to osmotic potential and hydrostatic pressure

upstream side of capillary: pressure potential on blood > osmotic potential → water/solutes leave capillary

downstream side of cap: osmotic potential > hydrostatic pressure of extracellular fluid → water/solutes enter capillary

t/f osmoconformers adjust only the extracellular fluid concentration to match with cell concentration

false; adjusts both EF and cell conc to match the environment conc

osmoregulators adjust conc of _____ _____ to match with ____ conc and has a ____ outer layer to protect against the environment conc

extracellular fluid; cell; thick

what is the difference between water loss/gain in fresh vs salt water animals

fresh: body is saltier than environment so water → body (water gain)

salt: environment saltier than body so water → environment (water loss)

marine bony fish are ______ so they are constantly ____ water to their surroundings

hypoosmotic; losing

how do marine bony fish counteract drying out

drink seawater in through gils → filter out sodium, chloride and potassium → produce small urine to get rid of extra solute

freshwater bony fish are ______ so they are constantly _____ water from environment

hyperosmotic; gaining

freshwater bony fish produce _____ amounts of _____ urine

large; dilute

t/f saltwater and freshwater bony fish drink

false; only saltwater

elasmobranches are _______ to seawater

isoosmotic

what makes up for the difference in concentration between elasmobranches and their environment

urea; elasmo less concentrated ions compared to surroundings

what is secreted from the rectal gland of elasmobranchs

very concentrated salt solution

t/f elasmobranchs still experience diffusion of ions through their gills

true

land animals experience constant water loss through ______

evaporation

where does evaporation in land dwellers occur

wet respiratory membrane & skin

why do land dwelling animals need a waterproof outer layer

minimize evaporation

t/f land animals should not limit salt intake

false; salt/electrolyte intake should be limited

excretion is the elimination of _____ from the body

waste

in the excretory tubule, what is the level of selectivity for these stages:

filtration

secretion

reabsorption

non selective filtration (molecules from blood goes into tubule) → selective reabsorption (nutrients/ions/conserved water goes back into blood) → selective secretion (excises ions/toxic products moved into tubule from blood)

what is the specialized layer of cells in excretory tubules that facilitates movement of substances

transport epithelium

the transport epithelium allows active transport of ions between ____ and _____

ECF; filtrate

different functions of the excretory tubule is localized along its ____

length