Transcript video slide - Mahopac Central School District

Chapter 44
Osmoregulation and
Excretion
PowerPoint TextEdit Art Slides for
Biology, Seventh Edition
Neil Campbell and Jane Reece
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Figure 44.1 Salvin’s albatrosses (Diomeda cauta salvini),
birds that can drink seawater with no ill effects
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Figure 44.2 Largemouth tilapia (Tilapia mossambica),
an extreme euryhaline osmoregulator
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Figure 44.3 Osmoregulation in marine and
freshwater bony fishes: a comparison
Gain of water and
salt ions from food
and by drinking
seawater
Excretion of
salt ions
from gills
Osmotic water loss
through gills and other parts
of body surface
Excretion of salt ions
and small amounts
of water in scanty
urine from kidneys
(a) Osmoregulation in a saltwater fish
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Osmotic water gain
through gills and other parts
of body surface
Uptake of
water and some
ions in food
Uptake of
salt ions
by gills
Excretion of
large amounts of
water in dilute
urine from kidneys
(b) Osmoregulation in a freshwater fish
Figure 44.4 Anhydrobiosis
100 µm
100 µm
(a) Hydrated tardigrade
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(b) Dehydrated
tardigrade
Figure 44.5 Water balance in two terrestrial mammals
Water
balance in a
kangaroo rat
(2 mL/day
= 100%)
Water
balance in
a human
(2,500 mL/day
= 100%)
Ingested
in food (750)
Ingested
in food (0.2)
Ingested
in liquid
(1,500)
Water
gain
Derived from
metabolism (250)
Derived from
metabolism (1.8)
Feces (0.9)
Water
loss
Urine
(0.45)
Evaporation (1.46)
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Feces (100)
Urine
(1,500)
Evaporation (900)
Figure 44.6 What role does fur play in water conservation
by camels?
EXPERIMENT Knut and Bodil Schmidt-Nielsen and their colleagues from Duke University observed that the
fur of camels exposed to full sun in the Sahara Desert could reach temperatures of over 70°C, while the
animals’ skin remained more than 30°C cooler. The Schmidt-Nielsens reasoned that insulation of the skin
by fur may substantially reduce the need for evaporative cooling by sweating. To test this hypothesis, they
compared the water loss rates of unclipped and clipped camels.
Removing the fur of a camel increased the rate of water loss through sweating by up to 50%.
Water lost per day
(L/100 kg body mass)
RESULTS
4
3
2
1
0
Control group
(Unclipped fur)
Experimental group
(Clipped fur)
CONCLUSION The fur of camels plays a critical role in their conserving water in the hot desert environments
where they live.
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Figure 44.7 Salt-excreting glands in birds
Nasal salt gland
(a) An albatross’s salt glands
empty via a duct into the
nostrils, and the salty
solution either drips off
the tip of the beak or is
exhaled in a fine mist.
Nostril
with salt
secretions
Lumen of
secretory tubule
Vein
Capillary
Secretory
tubule
(c) The secretory cells
Artery
actively transport salt
NaCl
from the blood into
Transport
the tubules. Blood
epithelium
flows counter to the
flow of salt secretion.
Direction
By maintaining a
of salt
Blood Secretory cell concentration gradient
movement
flow of transport
of salt in the tubule (aqua),
epithelium
this countercurrent
Central
system enhances salt
(b) One of several thousand secretory
duct
transfer from the blood
tubules in a salt-excreting gland. Each
to the lumen of the tubule.
tubule is lined by a transport epithelium surrounded
by capillaries, and drains into a central duct.
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Figure 44.8 Nitrogenous wastes
Nucleic acids
Proteins
Nitrogenous bases
Amino acids
–NH2
Amino groups
Many reptiles
Most aquatic
Mammals, most
(including
animals, including amphibians, sharks,
birds), insects,
most bony fishes some bony fishes
land snails
O
NH3
Ammonia
O
NH2
C
NH2
Urea
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O
HN
C
C
H
C N
C N
N
H
H
Uric acid
C O
Figure 44.9 Key functions of excretory systems: an overview
Capillary
Filtrate
Excretory
tubule
1 Filtration. The excretory tubule collects a filtrate from the blood.
Water and solutes are forced by blood pressure across the
selectively permeable membranes of a cluster of capillaries and
into the excretory tubule.
2 Reabsorption. The transport epithelium reclaims valuable substances
from the filtrate and returns them to the body fluids.
3 Secretion. Other substances, such as toxins and excess ions, are
extracted from body fluids and added to the contents of the excretory
tubule.
Urine
4
Excretion. The filtrate leaves the system and the body.
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Figure 44.10 Protonephridia: the flame-bulb
system of a planarian
Nucleus
of cap cell
Cilia
Interstitial fluid
filters through
membrane where
cap cell and tubule
cell interdigitate
(interlock)
Tubule cell
Flame
bulb
Protonephridia
(tubules)
Tubule
Nephridiopore
in body wall
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Figure 44.11 Metanephridia of an earthworm
Coelom
Capillary
network
Bladder
Collecting
tubule
Nephridiopore
Nephrostome
Metanephridia
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Figure 44.12 Malpighian tubules of insects
Digestive tract
Rectum
Intestine
Midgut
(stomach)
Hindgut
Malpighian
tubules
Feces and urine
Salt, water, and
nitrogenous
wastes
Anus
Malpighian
tubule
Rectum
Reabsorption of H2O,
ions, and valuable
organic molecules
HEMOLYMPH
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Figure 44.13 The mammalian excretory system
Posterior vena cava
Renal artery and vein
Aorta
Renal
medulla
Renal
cortex
Kidney
Ureter
Urinary bladder
Urethra
Renal
pelvis
(a) Excretory organs and major
associated blood vessels
JuxtaCortical
medullary nephron
nephron
Ureter
(b) Kidney structure
Afferent
arteriole
from renal Glomerulus
artery
Bowman’s capsule
Proximal tubule
Renal
cortex
Collecting
duct
To
renal
pelvis
Section of kidney from a rat
Peritubular capillaries
20 µm
Renal
medulla
(c) Nephron
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SEM
Efferent
arteriole from
glomerulus
Branch of
renal vein
Descending
Loop
limb
of
Ascending
Henle
limb
(d) Filtrate and
blood flow
Distal
tubule
Collecting
duct
Vasa
recta
Figure 44.14 The nephron and collecting duct:
regional functions of the transport epithelium
1 Proximal tubule
NaCl Nutrients
HCO3
H2O
K+
H+
NH3
4 Distal tubule
NaCl
H2O
HCO3
K+
H+
CORTEX
Filtrate
H2O
Salts (NaCl and others)
HCO3–
H+
Urea
Glucose; amino acids
Some drugs
2 Descending limb
of loop of
Henle
3 Thick segment
of ascending
limb
NaCl
H2O
OUTER
MEDULLA
NaCl
3 Thin segment
of ascending
limbs
Key
Active transport
Passive transport
5 Collecting
duct
Urea
NaCl
INNER
MEDULLA
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H2O
Paired Activity
• Explain how nephrons function to filter the
blood. Be sure to discuss the structure of
nephrons in your explanation.
• Generate a standards list if this was an essay
on the AP exam
• Create multiple sections and list exactly what
would be needed to earn each point
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 44.15 How the human kidney concentrates
urine: the two-solute model (layer 1)
Osmolarity of
interstitial
fluid
(mosm/L)
300
100
300
100
CORTEX
H2O
Active
transport
H2O
Passive
transport
H2O
OUTER
MEDULLA
H2O
300
300
400
200
400
400
600
400
600
600
900
700
H2O
H2O
INNER
MEDULLA
900
H2O
1200
1200
1200
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Figure 44.15 How the human kidney concentrates
urine: the two-solute model (layer 2)
Osmolarity of
interstitial
fluid
(mosm/L)
300
100
300
100
CORTEX
H2O
Active
transport
H2O
Passive
transport
H2O
OUTER
MEDULLA
H2O
INNER
MEDULLA
H2O
300
200
400
400
400
600
600
Nacl
400
Nacl
Nacl
Nacl
600
H2O
H2O
300
Nacl
900
Nacl
900
700
Nacl
1200
1200
1200
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 44.15 How the human kidney concentrates
urine: the two-solute model (layer 3)
Osmolarity of
interstitial
fluid
(mosm/L)
300
100
300
100
CORTEX
H2O
Active
transport
H2O
Passive
transport
H2O
OUTER
MEDULLA
H2O
Nacl
400
Nacl
600
INNER
MEDULLA
H2O
200
Nacl
Nacl
H2O
400
400
600
600
H2O
400
Nacl
900
300
H2O
Nacl
H2O
H2O
Nacl
300
700
H2O
H2O
Urea
H2O
Urea
H2O
Urea
900
1200
1200
1200
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Figure 44.16 Hormonal control of the kidney by
negative feedback circuits
Osmoreceptors
in hypothalamus
Homeostasis:
Blood pressure,
volume
Thirst
Hypothalamus
Drinking reduces
blood osmolarity
to set point
Increased Na+
and H2O reabsorption in
distal tubules
STIMULUS:
The juxtaglomerular
apparatus (JGA) responds
to low blood volume or
blood pressure (such as due
to dehydration or loss of
blood)
ADH
Increased
permeability
Pituitary
gland
Aldosterone
Distal
tubule
Arteriole
constriction
Adrenal gland
STIMULUS:
The release of ADH is
triggered when osmoreceptor cells in the
hypothalamus detect an
increase in the osmolarity
of the blood
H2O reabsorption helps
prevent further
osmolarity
increase
Angiotensin II
Distal
tubule
Collecting duct
Homeostasis:
Blood osmolarity
(a) Antidiuretic hormone (ADH) enhances fluid retention by making
the kidneys reclaim more water.
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Angiotensinogen
JGA
Renin
production
Renin
(b) The renin-angiotensin-aldosterone system (RAAS) leads to an increase
in blood volume and pressure.
Figure 44.17 A vampire bat (Desmodus rotundas), a
mammal with a unique excretory situation
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Figure 44.18 Environmental Adaptations of the
Vertebrate Kidney
MAMMALS
Bannertail Kangaroo rat
(Dipodomys spectabilis)
Beaver (Castor canadensis)
FRESHWATER FISHES AND AMPHIBIANS
Rainbow trout
(Oncorrhynchus mykiss)
Frog (Rana temporaria)
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BIRDS AND OTHER REPTILES
Roadrunner
(Geococcyx californianus)
Desert iguana
(Dipsosaurus dorsalis)
MARINE BONY FISHES
Northern bluefin tuna (Thunnus thynnus)