Ch. 50-Osmolarity, Kidney

Front 1

osmosis

Back 1

-diffusion of H2O across semipermeable membrane from MORE dilute sol'n to a LESS dilute sol'n (from HIGH [solute] to LOW [solute])

Front 2

osmotic pressure

Back 2

-measure of concentration difference
-amnt of pressure needed to balance the pressure created by movement of H2O

Front 3

osmolarity

Back 3

- # of osmotically active moles of solute per liter of sol'n
ex: 1 M sol'n of sucrose is 1 Osm but 1 M sol'n of NaCl is 2 Osm

Front 4

tonicity

Back 4

-measure of ability of the sol'n to change the volume of the cell by osmosis.

Front 5

hypertonic solution

Back 5

-cell in this environment LOOSES H2O to surrounding sol'n & SHRINKS

Front 6

hypotonic solution

Back 6

-cell in this environment GAINS H2O to surrounding sol'n & EXPANDS

Front 7

isotonic solution

Back 7

-shows NO NET movement of H2O

Front 8

osmoconformers

Back 8

-are in osmotic equilibrium w/ their environ.
-in most marine invertebrates
-extracellular fluids are ISOTONIC to seawater (thus no osmotic gradient exists)
-ex:hagfish, sharks, other cartilaginous fish

Front 9

osmoregulators

Back 9

-maintain relatively constant blood osmolarity despite differ concent. in surrounding environment
-their body fluids are either hypertonic or hypotonic to their environ.

Front 10

flame cells

Back 10

-found in invertebrates
-open to the outside of body but NOT inside
-movement of cilia w/in flame cell is what draws fluid in from body

Front 11

kidneys

Back 11

-filters & then reabsorbs
-filtrate enters tubules then gets modified to become urine
-glucose, a.a, vitamins,H20 are reabsorbed into blood

Front 12

nephrons

Back 12

- repeating units that make up the kidney
-structured as a loop that penetrates the mendulla

Front 13

glomerus

Back 13

-ball of capillaries
-reatains blood cells, proteins, and other large molecules
-allows H2o & other small molecules and waste to pass out

Front 14

Freshwater fish:

Back 14

-must RETAIN electrolytes/keep H2O OUT
-its HYPERTONIC to its environment
-must compensate for its tendancy to take in H2O (DONT DRINK water)

Front 15

Marine bony fish:

Back 15

-must EXCRETE electrolytes/keep H2O IN
-HYPOTONIC to its environment
-compensates for its loss of H2O (by DRINKING water)

Front 16

Cartilaginous fish:

Back 16

-PUMP OUT electrolytes & RETAIN URINE
-sharks & rays
-reabsorb urea from nephron tubules
-approx ISOTONIC to environment

Front 17

Amphibians:

Back 17

-same kidney as freshwater fish
-dilute urine
-compensate for loss of Na+ by actively transporting Na+ across skin

Front 18

Reptiles:

Back 18

-similar to freshwater fish
-marine reptiles, are same but tend to lose water & take in salts
-salt gland eliminates excess salt
-like marine bony fish (drink seawater/excrete ISOTONIC urine)

Front 19

Mammals & BIrds:

Back 19

-can excrete concentrated urine & retain water
-ONLY vertebrates that can do this
HYPERTONIC urine accomplished b/c of loop of Henle

Front 20

nitogenous waste

Back 20

-nitrogen containing by products
-a.a's and nucleic acids
ex:ammonia, urea, uric acid

Front 21

ammonia

Back 21

-NH3; derived from removal of NH2 group and its combo w/ H+ in the liver
-very TOXIC, must be removed fast
-not a problem for bony fish & amphibian tadpoles

Front 22

Urea

Back 22

-less toxic but different solubilities
-water soluble so excreted in large urine amounts
-found in this form in elasmobranchs, adult amphibians, mammals

Front 23

Uric acid

Back 23

-slightly soluble(so insoluble)
-can be excreted using little water
-reptiles, birds, insects excrete in this form
-forms guano (pasty white droppings in birds)

Front 24

Kidney functions:

Back 24

1. filtration
2. Reabsorption
3. Secretion

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Filtration

Back 25

-fluid in blood is FILTERED into the tubule sys
-comes from glomerous through renal tubule

Front 26

Reabsorption

Back 26

-selective flow of important solutes (glucose, a.a, inorganic ions)
-from filtrate to extracellular fluid to peritubular capillaries

Front 27

Secretion

Back 27

-movement of substance from blood into extracellular fluid then into filtrate
-adds to what will be expelled from body

Front 28

Nephron

Back 28

-filtering unit of kidney
-controls amnt of K+, H+, HCO3- excreted in urine
-mammal kidney contain juxtamedullary (long) & cortical nephrons (short)

Front 29

Bowman's Capsule

Back 29

-envelops the glomerulus like a balloon
-slits allow filtrate to enter nephron tubules

Front 30

peritubular capillaries

Back 30

-needed for reabsorption and secretion
-surrounds nephron tubules

Front 31

proximal convoluted tubule

Back 31

-reabsorbs nutrient molecules in the filtrate back into the blood
-driven by active transport of Na+ out of the filtrate

Front 32

Loop of Henle

Back 32

-creates a gradient of INC osmolarity from cortex to medulla
-allows H2O to reabsorb by osmosis in collecting duct

Front 33

ADH

Back 33

-antidiuretic hormone
-causes H2O to be conserved (hypertonic urine excreted)
-causes wall of distal convoluted tubule & collecting duct to be more permeable to H2O