lecture 10

Question 1

what is osmotic pressure

Answer 1

pressure that draws water by dissolved ions

Question 2

what is high osmotic pressre

Answer 2

more water, less solute

Question 3

what is low osmotic pressire

Answer 3

less water, more solute

Question 4

does ion equilibrium happen in animals

Answer 4

no - energy input is needed to balance ions

Question 5

what are the primary and secondary regulators of volume and ions

Answer 5

primary - gills

secondary - kidneys, do not deal with monovalent ions

Question 6

what is osmolarity

Answer 6

the measure of osmotic concentration in mOsm

Question 7

what is the osmolarity of FW

Answer 7

1-10 mOsm

Question 8

what is the osmolarity of SW

Answer 8

1000 mOsm

Question 9

describe the hag fish and how it regulates ion concentration

Answer 9

most primitive fish, do not have a jaw, raspar sucks on fluid (parasitic fish)

the only vertebrate that has the same osmolarity as SW

have slime glands

Question 10

what are the holes on the side of lampreys for

Answer 10

to breathe (gill slits) while they are feeding with raspar

Question 11

what is osmoconformity and what are its pros and cons

Answer 11

body fluid at different pressure than water

pro: cells surrounded by the same pressure
con: use ATP, gain and loss of ions

Question 12

what is osmoregulation and what are its pros and cons

Answer 12

following pressure of water

pro: not expensive
con: cells exposed to different pressures

Question 13

where would you normally see a change in pressure

Answer 13

brackish water

Question 14

what is hypo and hyperosmoregulation

Answer 14

hyper = above pressure

hypo = below pressure

Question 15

what is a good regulator

Answer 15

shrimp

Question 16

what is a good conformer

Answer 16

mussel

Question 17

what is a good semi-conformer

Answer 17

crab - regulates until 1100 mOsm, then conforms

Question 18

where would you see osmolarity higher than SW

Answer 18

tidepools

Question 19

describe FW teleost and their problems

Answer 19

hyperosmotic regulators

body = 290 mOsm, water at 10 mOsm

problems: gain of water by osmosis, loss of ions through diffusion

Question 20

what is the water problem in FW teleosts and what are the solutions

Answer 20

gaining too much water through osmosis

kidneys produce high volume dilute urine

Question 21

what is the ion problem in FW teleost fish and what are the solutions

Answer 21

ion loss in dilute water

gills have sodium-proton exchanger and chloride-bicarbonate exchanger

Question 22

what are the functions of the gills

Answer 22

ion regulation, pH regulation, ventilation and gas exchange

Question 23

describe the hydration of CO2

Answer 23

CO2 - carbonic acid - bicarbonate and proton

Question 24

describe the SW teleost fish (what regulator is it) and its internal pressures

Answer 24

hyporegulator

body = 330 mOsm, SW = 1000 mOsm

Question 25

what is the water problem for SW teleost fish

Answer 25

losing too much water through osmosis

solution: drink more water , produce little urine

Question 26

what is the ion problem for SW teleost fish and what are the solutions

Answer 26

gain of ions through diffusion

two pavement cells around one chloride cell

Na-K-ATPase pump moves 3 Na out and 2 K in - Na-2K-Cl co transporter moves said number of ions into the CC, where Na goes back to ATPase pump - Cl leaves via Cl channel on apical membrane, goes to boundary layer - negative charge causes Na to leave . the cell through electrical gradient - all K leaves through K channels on basolateral membrane into ECF

Question 27

what are the two types of ions in SW fish and where are they lost

Answer 27

divalent = feces or urine

monovalent = Na and Cl across gills

Question 28

what are the two types of membranes in the SW ion mechanism

Answer 28

basolateral membrane and apical membrane