Homeostasis - part 1 Flashcards Preview

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Flashcards in Homeostasis - part 1 Deck (23)
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1

What are the 5 basic groups of fish that display the different types of ionic regulation?

Hagfish - osmoconformer
Marine Fish
Freshwater Fish
Migratory Fish
Elasmobranchs

2

What is an osmoconformer?

Blood chemistry matches that of its environment. Narrow range in which it can live.

3

What is an osmoregulator?

Fish that will change blood osmolality/osmolarity to be different from its environment.

4

What is hyperosmoregulation?

Blood osmolarity above environment. (Freshwater)

5

What is hypoosmoregulation?

Blood osmolarity below environment, (Marine)

6

Describe a stenohaline fish.

Narrow range of environmental osmolarity that the fish can withstand.
Poor osmoregulator

7

Describe a euryhaline fish?

Can withstand a broad salinity range.
Good osmoregulator.

8

What is osmosis?

Passive movement of water along its concentration gradient.

9

For salwater fish, what is the direction of water flow?
Freshwater?

Salwater
- more salt in environment so water flows out of fish
Freshwater
- more particles in fish so water flows into the fish

10

What are the different ion exchange surfaces in fish?
What are the most important ones?

Gills
Kidneys
GI tract
Rectal Gland
Skin
Yolk Sac
Urinary bladder

Most important:
Gills
Kidneys
Rectal gland (elasmobranchs)

11

What are the two parts of gills important for ion exchange?

Filaments and lamellae

12

What are lamellae for?

Gas exchange

13

What are filaments for?

Support lamellae and are the site of osmoregulation, especially in teleosts.

14

How are kidneys involved in osmoregulation?

Reuptake water
absorb or secrete ions
get rid of wastes

15

How is the GI tract involved in osmoregulation?

Mostly in water exchange and uptake.

16

How is the Rectal gland involved in osmoregulation?

Location of ion exchange in sharks and rays (only in them).
Site of active excretion of ions (take from blood and excrete them)
Active transport of ions into rectal gland

17

What is the osmolarity of freshwater?
Of seawater?

1
1000 (ish)

18

How does a hagfish compare to osmolarity of a marine environment?

Largely the same for: Na, Cl, Ca, Urea and total.

19

How does the marine shark compare with the marine environment?

Total similar but higher
Urea way higher
sodium lower
Chloride lower

20

How does a marine teleost compare to a marine environment?

Na lower
Cl lower
Ca close but lower
Urea same
Total much lower

21

How does a freshwater shark compare to a freshwater environment?

Na higher
Cl higher
Calcium similar
urea similar
Total higher

22

How does a freshwater teleost compare to its environment?

Na higher
Cl higher
Ca same but higher
Urea same
Total higher

23

Contrast freshwater and marine teleosts for the following conditions:
Drinking water
Peeing a lot
Constantly losing ions
Osmolarity of pee
Hypotonic vs. hypertonic to the environment
Active ion regulation (Y/N)

Marine fish:
Drinks lots of water
Marine fish have a low amount of urine flow
High osmolarity for pee
Hypotonic to environment
Active ion regulation present
Not constantly losing ions

Freshwater fish:
Not drinking water
Constantly peeing
Pee has low osmolarity
Constantly losing ions
Hypertonic to environment
Active ion regulation