Chapter 44 key terms

Question 1

Osmoregulation

Answer 1

controls solute concentrations and balances water gain and loss

Question 2

Excertion

Answer 2

ridding the body of nitrogenous metabolites and other metabolic waste products

Question 3

Osmolarity

Answer 3

the solute concentration of a solution

Question 4

hypoosmotic

Answer 4

less concentrated

Question 5

hyperosotic

Answer 5

more concentrated

Question 6

Osmoconformers

Answer 6

are isoosmotic with their surroundings and do not regulate their osmolarity

Question 7

Osmoregulators

Answer 7

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

Question 8

Ammonia

Answer 8

a toxic metabolite produced by breakdown of nitrogenous molecules

Question 9

Transport epithelia

Answer 9

epithelial cells specialized for controlled movement of solutes in specific directions

Question 10

Urea

Answer 10

less toxic than ammonia

Question 11

Uric Acid

Answer 11

uric acid is relatively nontoxic and does not dissolve readily in water. insects, land snails, and many reptiles excrete

Question 12

filtrate

Answer 12

filtering of body fluids

Question 13

reabsorption

Answer 13

recovering valuable solutes

Question 14

secretion

Answer 14

adding nonessential solutes and wastes to the filtrate

Question 15

kidneys

Answer 15

the excretory organs of vertebrates and some chordates, function in both exertion and osmoregulation

Question 16

ureter

Answer 16

urine produced by each kidney exits the renal pelvis through this duct

Question 17

urinary bladder

Answer 17

ureters drain into a common sac

Question 18

urethra

Answer 18

urine is expelled from the bladder through a tube called

Question 19

glomerulus

Answer 19

nephrons consist of a long tubule and ball of capillaries

Question 20

three major regions of the nephron

Answer 20

proximal tubule
loop of henle
distal tubule

Question 21

collecting duct

Answer 21

receives the processed filtrate from many nephrons and transports it to the renal pelvis

Question 22

Descending limb of the loop of henle

Answer 22

reabsorption of water continues through a channel formed by aquaporin proteins

Question 23

Proximal Tubule

Answer 23

reabsorption of ions, water and nutrients takes place here

Question 24

ascending limb of the loop of henle

Answer 24

salt but not water is able to diffuse from the tubule into the interstitial fluid

Question 25

collecting duct

Answer 25

carries filtrate through the medulla to renal pelvis

Question 26

Antidiuretic Hormone (ADH)

Answer 26

initiates a signal cascade leading to the insertion of aquaporin proteins into the membrane lining the collection duct. increases water recapture reduces urine volume

Question 27

Renin-angiotensin-aldosterone system (RAAS)

Answer 27

a complex feedback circuit that functions in homeostasis. increases absorption and increases blood pressure

Question 28

ANP

Answer 28

decreases absorption and decreases blood pressure