osmoregulation and excretion

Question 1

osmoregulation

Answer 1

regulates solute concentrations and balances the gain and loss of water

Question 2

what does excretion do?

Answer 2

gets rid of nitrogenous metabolites and other waste products

Question 3

osmosis

Answer 3

movement of water across a selective permeable membrane

Question 4

osmolarity

Answer 4

the solute concentration of a solution, determines the movement of water across a selectively permeable membrane

Question 5

osmoconformers

Answer 5

found only in some marine animals.
are isoosmotic with surroundings.
do not regulate osmolarity.
can be stenohaline (narrow) or euryhaline (wide) in tolerance.

Question 6

osmoregulators

Answer 6

expend energy to control water uptake in a hypoosmotic environment and loss in a hyperosmotic environment

Question 7

explain how marine bony fish are hypoosmotic to seawater

Answer 7

they lose water by osmosis and gain salt by diffusion and from food. they balance water loss by drinking seawater and excreting salts.

Question 8

what is anhydrobiosis?

Answer 8

some aquatic invertebrates lose almost all their body water and survive in a dormant state.

Question 8

explain how freshwater animals are hypoosmotic to their environment

Answer 8

they constantly take in water by osmosis.
they loose salts by diffusion and maintain water balance by excreting large amounts of dilute urine.
salts lost by diffusion are replaced in foods and uptake across gills

Question 9

what are some adaptions of the kangaroo rat to conserve water?

Answer 9

concentrate urine
dry feces
produce uric acid instead of urea

Question 10

transport epithelia

Answer 10

are specialized epithelial cells that regulate solute movement. essential components of osmotic regulation and metabolic waste disposal. Arranged in complex tubular networks.

Question 11

how do seabirds eliminate excess salt from their bodies?

Answer 11

salt glands which remove excess sodium chloride from the blood

Question 12

Ammonia in terms of nitrogenous waste

Answer 12

toxic needs lots of water. Common in aquatic species

Question 13

urea

Answer 13

the liver in mammals converts ammonia to less toxic urea. the circulatory system carries urea to kidneys where it is excreted. less water to excrete than ammonia nut energetically expensive to convert

Question 14

uric acid

Answer 14

excreted by insects, snails and reptiles. largely insoluble in water, can be secreted as a paste with little waterloss. more energetically expensive than urea

Question 15

filtration

Answer 15

pressure-filtering of body fluids

Question 16

reabsorption

Answer 16

reclaiming valuable solutes

Question 17

secretion

Answer 17

adding toxins and other solutes from the body fluids to the filtrate

Question 18

excretion

Answer 18

removing the filtrate from the system

Question 19

protonephridia

Answer 19

network of tubules in flame cells/planaria

Question 20

metanephridia

Answer 20

network of tubules in earthworms. similar to nephrons

Question 21

malpighian tubules

Answer 21

network of tubules in insects

Question 22

nephrons

Answer 22

network of tubules in humans. the functional unit of the kidney

Question 23

Protonephridium

Answer 23

a network of dead-end tubules connected to external openings. The smallest branches of the network are capped by a cellular unit called a flame bulb. Excrete a dilute fluid and function is osmoreuglation

Question 24

Metanephridia

Answer 24

Each segment of an earthworm has a pair of open-ended metanephridia. Both excretory and osmoregulatory functions. Consists of tubules that collect coelomic fluid and produce dilute urine for excretion.

Question 25

Malpighian tubules

Answer 25

in insects and arthropods. remove nitrogenous wastes from hemolymph and function is osmoregulation. MT open into digestive tract. Insects produce a dry waste matter, highly efficient in water conservation.

Question 26

kidneys

Answer 26

excretory organs of vertebrates, function in both osmoregulation and excretion. principle site of water balance and salt regulation

Question 27

what is the kidney blood supply

Answer 27

supplied by a renal artery and drained by a renal vein

Question 28

how does urine exit the kidney?

Answer 28

through a duct called the ureter, both ureters drain into the bladder and urine is expelled through the uretha

Question 29

the nephron

Answer 29

the functional unit of the vertebrate kidney consists of a single long tubule and a ball of capillaries called the glomerulus

Question 30

bowmans capsule

Answer 30

surrounds and receives filtrate from the glomerulus capillaries

Question 31

how does filtration occur ?

Answer 31

as blood pressure forces fluid from the blood in the glomerulus to lumen of the bowmans capsule

Question 32

is filtration of small molecules selective

Answer 32

no

Question 33

what does the filtrate contain?

Answer 33

salts, glucose, amino acids, vitamins, nitrogenous wastes and other small molecules

Question 34

what is the pathway of the filtrate ?

Answer 34

proximal tubule> loop of henle> distal tubule

Question 35

Vasa rectA

Answer 35

capillaries that serve as the loop of henle

Question 36

how do the vasa recta and loop of henle function?

Answer 36

as a counter current system

Question 37

how does the kidney conserve water?

Answer 37

producing urine that is much more concentrated than bodily fluids

Question 38

what happens in the proximal tubule?

Answer 38

Reabsorption of ions, water and nutrients. Molecules are transported actively and passively from the filtrate into the interstitial fluid and then capillaries. Some toxic materials are secreted into the . The filtrate volume decreases

Question 39

What happens in the descending limb of the loop of henle

Answer 39

Reabsorption of water continues through channels formed by aquaporin proteins. Movement is driven by the high osmolarity of the interstitial fluid, which is hyperosmotic to the filtrate. The filtrate becomes increasingly concentrated

Question 40

What happens in the ascending loop of henle?

Answer 40

salt but not water is able to diffuse from the tubule into the interstitial fluid. the filtrate becomes increasingly dilute

Question 41

dital tubule

Answer 41

regulates the k+ and NaCl concentrations of body fluids

Question 42

collecting duct

Answer 42

carries filtrate through the medulla to the renal pelvis. water is lost as well as some salt and urea and the filtrate becomes more concentrated.

Question 43

is urine hyperosmotic to body fluids

Answer 43

yes

Question 44

How much filtrate to human kidneys produce per day

Answer 44

180 L

Question 45

what is reabsorbed?

Answer 45

99% of water and nearly all sugars, vitamins and amino acids