Urinary System-Chapter 50 Flashcards
what must an animal’s body be able to do in order to maintain osmotic balance?
(1) take in water from environment
(2) excrete excess water into the environment
(3) exchange solutes to maintain homeostasis
the measure of a solution’s ability to change the volume of a cell by osmosis
osmotic pressure
the measure of a solution’s ability to change the volume of a cell by osmosis
tonicity
more solute, less water, will take in water from surroundings
hypertonic
less solute, more water, will lose water to surroundings
hypotonic
equal water exchange with surroundings
isotonic
water will always move from ______ to _________
hypotonic to hypertonic
organisms that are in osmotic equilibrium with their environment, most marine invertebrates and chondrichthythes
osmoconformers
maintain a constant (hypertonic or hypotonic), includes most vertebrates and all terrestrial animals
osmoregulators
produced when amino acids and nucleic acids are broken down, the amino group is removed and __________ is formed
ammonia (NH3)
ammonia is only safe in dilute concentrations, excessive accumulation of ammonia derivatives in joints causes _______ in humans
gout
How do bony fishes and immature amphibians eliminate nitrogenous waste?
by diffusion via the gills
Who do chondrichthyes, adult amphibians and mammals eliminate nitrogenous waste?
convert ammonia into urea which is dissolved in water
How do birds, reptiles and insects eliminate nitrogenous waste?
convert ammonia into water insoluble uric acid, uses more carbon
way for nitrogenous waste to be excreted through a membrane
vacuoles
flatworms have a network of tubes called __________ that branch into bulblike _________
protonephridia
flame cells
remove solutes and excess water from the body
flame cells
open to the outside of the body through a pore
protonephridia
one in each segment of an earthworm, a series of convoluted tubules that remove excess water and solutes from blood and produce urine, urine excreted through a pore
nephridia
extensions of the digestive tract seen in insects, water and K+ are secreted into tubules by active transport, create an osmotic gradient that draws water into the tubules by osmosis, waste left behind and water and K+ reabsorbed
malphigian tubules
cartilaginous fish are _________ compared to sea water, most of the urea is reabsorbed and pooled in the blood, solute concentration in blood is equal to the sea water
isotonic
saltwater bony fish are __________ to the sea water, water wants to leave their bodies therefore they drink large amounts of seawater, ions in blood eliminated across gill surface
hypotonic
freshwater bony fish are __________ to the fresh water, water wants to enter their body from the environment, kidney produces large amounts of dilute urine, reabsorb ions across nephrons
hypertonic
terrestrial reptiles absorb much of the salt and water in their blood in the kidney, move the dilute urine into the ______ where water is reabsorbed
cloaca