Chapter 44: Osmoregulation and Excretion

Question 0

Excretion

Answer 0

How the body rids itself of nitrogenous metabolizes and metabolic waste products

Question 1

Osmoregulation

Answer 1

How animals control solute concentrations and balance water gain or loss

Question 2

Osmoconformer

Answer 2

To be isoosmotic with surroundings: always marine animals

Question 3

Osmoregulator

Answer 3

Control internal osmolarity independent of that of its environment

Question 4

Stenohaline

Answer 4

Cannot tolerate substantial changes in external osmolarity

Question 5

Euryhaline

Answer 5

Can survive large fluctuations in external osmolarity

Question 6

How do osmoregulating marine fish balance water loss from the hyper osmotic salt water?

Answer 6

Drink excess water, rid selves of salts through gills and kidneys

Question 7

Hemolymph

Answer 7

Fluid surrounding cells in an open circulatory system like insects

Question 8

Interstitial fluid

Answer 8

Fluid surrounding cells in closed circulatory system, like vertebrates

Question 9

Transport epithelia

Answer 9

One or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions

Question 10

Ammonia

Answer 10

Very toxic, usually excreted very dilutely, eg fish across gills

Question 11

Urea

Answer 11

Slightly toxic, less water loss, humans, etc.

Question 12

Uric acid

Answer 12

Nontoxic, guano, solid paste

Question 13

Filtration

Answer 13

Driven by hydrostatic pressure, drives water, small solutes, etc across membranes to form filtrate

Question 14

Excretory system in flatworms aka Platyhelminthes

Answer 14

Protonephridia: dead end tubules ending in flame bulbs, connected to external openings

Question 15

Excretory system of annelids

Answer 15

Metanephridia: collect fluid directly from coelom, enveloped in capillary network, cilia

Question 16

Excretory system of insects

Answer 16

Malpighian tubules: dead end tips immersed in hemolymph, connect to digestive tract

Question 17

Where does blood come to the kidneys from?

Answer 17

Renal artery: to outer renal cortex and inner renal medulla

Question 18

Describe flow in nephrons

Answer 18

Glomerulus in Bowman’s capsule, to proximal tubule, to loop of Henle, to distal tubule, to collecting duct

Question 19

What is reabsorbed in the proximal tubule?

Answer 19

Ions, water, nutrients: NaCl moves from filtrate to interstitial fluid, water follows by osmosis int peri tubular capillaries

Question 20

What happens in the descending limb of the loop of Henle?

Answer 20

More reabsorption of water through aquaporin-protein-formed channels

Question 21

What happens in the ascending loop of Henle?

Answer 21

Not permeable to water, only ions: NaCl diffuses out in lower, thinner segment, and actively transported out at thicker top segment to make the filtrate more dilute

Question 22

What happens in the distal tubule?

Answer 22

K+ secreted into filtrate, NaCl reabsorbed

Question 23

What two substances help control pH in kidneys?

Answer 23

Secretion of H+ and reabsorption of HCO3-

Question 24

Where is there the highest filtrate concentration in nephrons?

Answer 24

Bottom of loop of Henle

Question 25

Countercurrent multiplier system

Answer 25

Countercurrent systems that expend energ to create condensation gradients

Question 26

Vasa recta

Answer 26

Hair pin shaped capillaries that serve the renal medulla