Osmoregulation and excretion

Question 1

What do excretory systems do?

Answer 1

Control Volume, Concentration, And Composition Of Body Fluids.

Dispose of Metabolic Waste

Question 2

What must be maintained for cellular water balence?

Answer 2

the osmolarity of extracellular fluid

Question 3

Osmolarity of a solution:

Answer 3

The number of moles of active solutes per liter of solvent; expressed as milliosmoles/L (mosm/L),
or milliosmoles/Kg

Question 4

Average osmolarity of seawater

Answer 4

~3.5% salinity = 35 ppt = 1000mosm/L

Question 5

Osmoconformers

Answer 5

equilibrate their osmolarity with seawater; many marine invertebrates are osmoconformers.

Question 6

Osmoregulators

Answer 6

maintain osmolarities lower than seawater.

some marine invertebrates. all freshwater animals and all terrestrial animals.

Question 7

What is the adaptive value of osmoconformity?

Answer 7

Don’t have to expend energy to osmoregulate, since they don’t osmoregulate.

Question 8

In high osmolarity, ____ is actively transported out through the gills, and ____ ions follow

Answer 8

Cl-

Na+

Question 9

In low osmolarity, the transport of___ is reversed into _____

Answer 9

Cl-

active transport.

Question 10

Are marine invertebrates osmoregulators?

Answer 10

Some of them

Question 11

TMAO

Answer 11

trimethylamine oxide

stabilizes proteins and cellular structures

Question 12

In Cartilaginous Fish

(Sharks, rays, and skates) what is their internal fluid osmolarity compared to their environment?

Answer 12

internal fluid is similar in osmolarity to seawater so water is not lost by osmosis to the environment

Question 13

how do Cartilaginous Fish

(Sharks, rays, and skates) excrete NaCl?

Answer 13

Their rectal gland actively secretes chloride ions, with sodium ions following.

Question 14

how do Cartilaginous Fish

(Sharks, rays, and skates) Maintain high internal osmolarity?

Answer 14

By accumulating higher than normal levels of urea, and a special metabolite called TMAO*

Question 15

Anadromous Fish

Answer 15

live Part of their lifecycle in freshwater, and part in saltwater

Question 16

How do birds excrete salt?

Answer 16

Birds use nasal glands that release salt excretions into the nasal passages

Question 17

Sea turtles have modified _________

Answer 17

tear ducts they secrete salt into the orbit of the eye.

Question 18

______ Conserve Some Ions And Excrete Others in order to______

Answer 18

Ionic Regulators

Maintain Ionic Composition

Question 19

Ammonia

Answer 19

(NH3) is the most common nitrogenous waste; highly toxic at even moderate concentrations.

soluble in water

Question 20

ammonotelic

Answer 20

aquatic animals that secrete NH3 through their gills

Question 21

Terrestrial animals must convert NH3 to ______.

Answer 21

urea or uric acid.

Question 22

How many different types of nitrogenous waste do most species secrete?

Answer 22

Most species secrete more than one nitrogenous waste

Question 23

Humans are ureotelic but also excrete:

Answer 23

Uric acid—from metabolism of nucleic acids and caffeine.

Ammonia—regulates pH of extracellular fluid by buffering urine.

Question 24

nitrogenous waste

Answer 24

Carbohydrates and lipids are metabolized to water and CO2 and are easily excreted.

Proteins and nucleic acids contain nitrogen so metabolism produces nitrogenous waste

Question 25

animals must eliminate __________

Answer 25

Metabolic Waste Products

Question 26

Excretory system have three processes in common:

Answer 26

Filtration.
Reabsorbtion.
Secretion

Question 27

Filtration

Answer 27

extracellular fluid is filtered to contain no cells or large molecules

Question 28

Reabsorption

Answer 28

valuable solutes recovered; concentration of filtrate (now urine), excretion of waste

Question 29

Secretion

Answer 29

waste actively secreted; modifies the filtrate

Question 30

Excretory organs control _____ and the volume of_______ while expelling nitrogenous waste

Answer 30

osmolarity.

extracellular fluids.

Question 31

Protonephridium:

Answer 31

dead-end tubules that lead to a opening in the body wall.

Fluid is modified to conserve ions and excrete water.

Question 32

Cilia in Protonephridium

Answer 32

beat, creating negative pressure, causing fluid to enter the tubule.

Question 33

Planaria

Answer 33

excrete water through tubules that end in flame cells, which have beating cilia.

Question 34

What is a major environmental challenge for insects?

Answer 34

conserving water

Question 35

The insect body is covered in ____

Answer 35

water impermeable wax

Question 36

Tubule cells ____ transport uric acid, K+, and Na+ into the tubules.

Answer 36

actively

Question 37

Malpighian tubules

Answer 37

The insect excretory system consists of Malpighian tubules—blind-ended tubules that open into the gut.

Question 38

In earth worms what happens if blood is pumped under pressure?

Answer 38

I can cause Blood To Filter Across Capillary Walls

Question 39

In earthworms, what enters the coelem?

Answer 39

Water, small molecules, and some waste products