SALT AND WATER BALANCE

Question 1

Outline countercurrent exchange

Answer 1

pressure of O2 is shared between two anti-parallel tubules. therefore one increases in pressure and one decreases

Question 2

outline concurrent exchange

Answer 2

pressure of O2 is shared between two parallel tubules. therefore one increase and one decrease in pressure however final pressure is the same

Question 3

what is osmoregulation

Answer 3

osmoregulation is the controlled movement of solutes between internal fluid and environment

Question 4

what is osmolarity

Answer 4

refers to the sum of all osmotically active particles

Question 5

hypertonic

Answer 5

higher solute conc outside

Question 6

hypotonic

Answer 6

lower solute conc outside

Question 7

isotonic

Answer 7

equal solute conc on inside and outside

Question 8

what is an osmoconformer

Answer 8

organism that does not adjust internal conc

Question 9

what is an osmoregulator

Answer 9

use energy to regulate internal conc.

Question 10

marine fish are:

Answer 10

isosmotic to environment

Question 11

fresh water fish are:

Answer 11

hyposmotic to environment. Because of this they actively expel water and have a slimy coat to stop solute movement.

Question 12

marine fish osmoregulate by:

Answer 12

• drinking (inc H2O and salt)
• loss of H2O and salt through gills
• excretion of excess ions and small amount of H2O from urine

Question 13

fresh water fish osmoregulate by:

Answer 13

• uptake of some ions in food
• uptake of salt and H2O through gills
• excretion of large H2O in urine

Question 14

elasmobranches osmoregulation

Answer 14

keep urea in tissues and are isosmotic.

Question 15

air breathing marine vertebrates osmoregulation

Answer 15

they need specialised structures like kidneys or salt glands to excrete large amounts of salt

Question 16

outline tubular excretory systems

Answer 16

• found in insects and metanphridia
  filtration: blood enters into filtrate
  reabsorption: important molecules to bloodstream
  secretion: into filtrate from bloodstream
  excretion: get out of body

Question 17

outline the kidney excretory system

Answer 17

• vital organ, lies along vertebral column,
• blood transported by renal artery and vein.
• solution enters glomerulus to be filtered

Question 18

where is the medulla and cortex

Answer 18

cortex is outside of kidney and medulla is inside. solution travels through cortex to inner medulla

Question 19

a larger loop of henle =

Answer 19

more concentrated urine

Question 20

steps of urine travel

Answer 20

kidney
to ureter
to urea

Question 21

steps of blood through kidney

Answer 21

1. proximal tubule
2. loop of henle
3. ascending limb
4. distal tubule
5. collecting duct

Question 22

what is this filtration tubule unit in kidney called

Answer 22

a nephron