Ch 48 Osmoregulation and Disposal of Metabolic Wastes

Question 1

– active regulation of osmotic pressure of body fluids
– maintains fluid and electrolyte homeostasis
– electrolyte

Answer 1

Osmoregulation

Question 2

Dissociates into ions when dissolved in water, can conduct an electric current.

Answer 2

Electrolyte

Question 3

– process of ridding body of metabolic wastes

– Excretory systems function in both osmoregulatrion and disposal of wastes

Answer 3

Excretion

Question 4

Principal metabolic wastes of animals are

Answer 4

CO2, H2O, and nitrogenous compounds

Question 5

: toxic nitrogenous compound
– a product of catabolism of amino acids and nucleic acids
– excreted mainly by aquatic animals

Answer 5

Ammonia (NH3)

Question 6

– Require additional energy expenditure
– Urea
• principal nitrogenous excretion of amphibians and mammals
• soluble in water
– Uric acid (non-toxic)
• excreted by reptiles, birds, and insects
• insoluble in water; excreted as semisolid paste
• requires less water for excretion than urea

Answer 6

Less Toxic Nitrogen Waste Compounds

Question 7

Animals with blood vessels

Answer 7

Excretory Systems

Question 8

– tubules open at both ends

– some annelids and mollusks

Answer 8

Metanephridia

Question 9

Fluid from coelom into tubule.

– needed materials reabsorbed by

Answer 9

Capillaries

Question 10

Concentrated urine exits body through

Answer 10

Nephridiophores

Question 11

Excrete nitrogenous wastes in urine in vertebrates

• maintain fluid balance by adjusting salt and water content

Answer 11

Kidneys

Question 12

• Take in water osmotically

– excrete large volume of hypotonic (dilute) urine

Answer 12

Freshwater Fishes

Question 13

• Lose water osmotically
• Compensate by drinking sea water and excreting salt and ammonia through their gills
• Produce only a small volume of isotonic urine

Answer 13

Marine Bony Fishes

Question 14

– efficient kidneys and bladders

– excretion of uric acid

Answer 14

Water conservation strategies

Question 15

– have a high metabolic rate

– produce large volume of nitrogenous wastes

Answer 15

Endotherms

Question 16

birds (like other reptiles) nitrogenous waste:

Answer 16

Uric acid

Question 17

Mammals nitrogenous waste:

Answer 17

Some through skin

- mostly through urinary system

Question 18

• Principal excretory system in mammals

Answer 18

The Urinary System

Question 19

Mammalian kidneys produce _____
– passes through ureters
– to urinary bladder for storage

Answer 19

Urine

Question 20

• Urine is released from the body (urination) – through the

Answer 20

Urethra

Question 21

– outer portion of kidney

Answer 21

Renal cortex

Question 22

– inner portion of kidney

– contains 8 to 10 renal pyramids

Answer 22

Renal medulla

Question 23

– Urine from collecting ducts flows through the tip of each pyramid into the renal pelvis (funnel-shaped chamber)

Answer 23

Renal pyramids

Question 24

– functional units of kidney
– cluster of capillaries (glomerulus)
– surrounded by a Bowman’s capsule
• that opens into a long, coiled renal tubule

Answer 24

Nephron

Question 25

Renal tubule consists of

Answer 25

– proximal convoluted tubule
– loop of Henle
– distal convoluted tubule

Question 26

– mostly in cortex

Answer 26

Cortical nephrons

Question 27

– extend deep into medulla

– important in concentrating urine

Answer 27

Juxtamedullary nephrons

Question 28

• Two levels of capillaries 
• Blood flows
– from renal artery
– to afferent arterioles
– to glomerular capillaries
– into an efferent arteriole
– delivers blood into peritubular capillaries that surround the renal tubule
• Blood leaves kidney through renal vein

Answer 28

Renal Blood Vessels

Question 29

Filters through glomerular capillaries into Bowman’s capsule

Answer 29

Pressurized plasma

Question 30

– permeable walls of capillaries

– filtration slits between podocytes

Answer 30

Filtration membrane

Question 31

– specialized epithelial cells

– make up inner wall of Bowman’s capsule

Answer 31

Podocytes

Question 32

Filtration is ________
– small molecules become part of filtrate
– glucose, other needed materials, metabolic wastes

Answer 32

Nonselective

Question 33

Water solution of nitrogenous wastes, excess salts, and other,substances not needed by the body (generally sterile)
• Filtration
– of plasma 
• Reabsorption
– of needed 
• Secretion
– of extra K+, H+, materials etc. into renal tubule
• Results in Urine

Answer 33

Urine Production