Download Chapter 25 Student Notes

BIOLOGY
CONCEPTS & CONNECTIONS
Fourth Edition
Neil A. Campbell • Jane B. Reece • Lawrence G. Mitchell • Martha R. Taylor
CHAPTER 25
Control of the Internal
Environment
Modules 25.1 – 25.4
From PowerPoint® Lectures for Biology: Concepts & Connections
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Let Sleeping Bears Lie
• Bears don’t technically hibernate
– They do enter a ________ state, when their
body temperature drops by several degrees
• Bears are ________ (“warm blooded”)
– Endothermic animals derive
most of their body heat from
________(cellular respiration)
– ________ animals warm
themselves mainly by absorbing
heat from their _________________
(“cold blooded”)
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• Dormant bears have ________ homeostatic
mechanisms that compensate for fluctuations
in the external environment
– _____________ maintains
the body temperature within
a tolerable range
– _____________ controls
the gain and loss of water
and dissolved solutes
– _____________ is the
disposal of metabolic wastes
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THERMOREGULATION
Heat is gained or lost in four ways
• Body temperature regulation requires _____________
to heat gained from or lost to an animal’s environment
• _____________– go somewhere to absorb heat energy
• _____________– go in shade, water or open mouth
Convection
Radiation
Evaporation
Conduction
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Figure 25.1
• Lizard on rock
Figure 25.1x
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• Harbor seal
Figure 25.2x2
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• Fox in snow
Figure 25.2x1
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Thermoregulation depends on both heat
production and heat gain or lost
• Both endotherms and ectotherms may change
their rate of _____________
• _____________ may sleep, shed
winter/spring coat/fur, feathers, put on extra
insulation (fat)
• Humans may lose heat by sweating/perspiring
(evaporative cooling)
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• _____________ changes may increase heat
production by raising the metabolic rate
– Fur and feathers help the body retain heat
– Shivering, as these honeybees are doing, also
increases metabolic _____________
Figure 25.2A
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• Blood flow to the skin affects heat loss, send warm blood to
the skin, promotes heat loss with the environment
• To conserve heat move blood away from skin, constrict
blood vessels
Top view of shark
Skin
Blood vessels
of gills
Artery
Vein
Capillary network
within muscle
Heart
Artery and vein
under the skin
Dorsal aorta
Figure 25.2B
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• In a _____________ heat
exchanger, blood from the
core body warms cooler
blood returning from the
gills or limbs
Body surface (cool)
• Fish move blood and water
in _____________ across
their gills.
Blood
flow
• This process __________
body heat
Heat
transfer
18˚
C
20˚
C
20˚
22˚
22˚
24˚
24˚
26˚
Inner body (warm)
Figure 25.2C
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Behavior often affects body temperature
Figure 25.3
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Reducing the metabolic rate saves energy
• _____________ is a state of reduced activity
and lowered metabolic rate
– _____________
in cold
weather (bear)
– _____________
in warm
weather (hummingbird)
Figure 25.4
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• Land animals gain water by drinking and
eating
– They _____________ and solutes by
evaporation and waste disposal
– Their kidneys, behavior, and waterproof skin
_____________
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Connection: Sweating can produce serious water
loss
• Water lost in _____________ can cause
osmoregulatory problems
– _____________
is the best way
to prevent
dehydration
during exercise
Figure 25.6
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• Changes in water amounts inside the cells of
organisms can create _____________
challenges.
• Most organisms try to _____________ water
balance in their cell(s), called osmoregulation
• Many animals also _____________
metabolic wastes when they remove excess
water during the process of excretion
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• Metabolic wastes include:
– ___________ from dehydration synthesis,
eating/drinking, cellular respiration
– _____________ from protein and nucleic acid
(DNA/RNA) metabolism
– Liver converts some amino acids into other types by
taking off amino groups in a process called _________
– This produces _____________ (toxic), very soluble
– Liver combines _________________ to produce
urea, much less toxic and can be stored
– Some land animals save water by excreting a virtually
dry waste called _____________
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Animals must dispose of nitrogenous wastes
• Different animals excrete different types of
nitrogenous wastes.
• _____________(including protein)
• ALL animals produce _____________
• Type of nitrogenous waste produced and how
it is excreted is determined by where they live
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Proteins
Nucleic acids
Amino acids
Nitrogenous bases
–NH2
Amino groups
Most aquatic animals,
including many fishes
Mammals, amphibians,
sharks, some bony fishes
Ammonia
Birds, insects, many
reptiles, land snails
Urea
Uric acid
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Figure 25.8
• Fish and many other aquatic animals excrete
ammonia _____________ into water
• Many land animals (mammals), sharks and
some bony fish _____________
• Many birds, insects, reptiles excrete
________. Dry form of waste, usually white
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How do organisms perform excretion?
• Protozoa, small, unicellular, live in water, cell
membrane is excretory structure, excrete
wastes __________________ .
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• Cnidaria (hydra, anemone, jellyfish), simple
animals, 2 cell layers & hollow body cavity, live in
water, each cell excrete wastes _____________ .
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• Earthworm (annelid), segmented worm, more
complex, have tissues, organ systems and blood
(closed _____________ ), each segment has a
pair of filtering and excretory structures called
_____________ .
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• Grasshopper (arthropod), exoskeleton & jointed
appendages, open circulatory system, blood not
always in vessels, has _____________ that
absorb waste directly from blood and put into
_____________ .
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The excretory system plays several major roles in
homeostasis
• The excretory system
– expels __________
– regulates
_____________
Kidneys filter blood
remove:
(Inferior
vena cava)
Renal artery
and vein
• ________
• ________
Kidney
(Aorta)
Ureter
Bladder
Urethra
• ________
A. THE EXCRETORY SYSTEM
Forms urea altogether
Figure 25.9A
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• The two human kidneys each contain about
1.25 million functional units called ________
and filter about _____________ (liquid
filtered from blood) each day, only excrete
about 1-2 liters of urine, rest (179-178 liters) is
_____________
• Urine leaves the kidneys via the ureters
– It is stored in the _____________
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Kidney has 3 functional regions:
_______ – outer region: filtration
_______– middle region: concentrate urin3
_______– innermost region: collects urine and sends
out of kidney
Renal
medulla
Renal
cortex
Renal
pelvis
Bowman’s
capsule
Nephron
tubule
Renal
cortex
Renal artery
Renal vein
Collecting
duct
Renal
medulla
Ureter
To
renal
pelvis
B. THE KIDNEY
C. ORIENTATION OF A NEPHRON WITHIN THE KIDNEY
Figure 25.9B, C
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• Each nephron consists of
a folded tubule and
associated blood vessels
– The nephrons extract a
filtrate from the blood in a
capillary ball called the
_____________ due to
the _____________ of
the blood in the capillary
and collect the filtrate into
the _____________
Bowman’s capsule
Arteriole
from renal
artery
1 Proximal tubule
Glomerulus
Capillaries
Arteriole
from glomerulus
Branch of
renal vein
3 Distal
tubule
From
another
nephron
Collecting
duct
2 Loop of Henle
– They refine the filtrate into
a much smaller amount of
urine
with capillary
network
D. DETAILED STRUCTURE OF A NEPHRON
Figure 25.9D
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Overview: The key functions of the excretory
system are filtration, reabsorption, secretion,
and excretion
• There are four steps (processes, parts) involved in
urine production:
• _____________ : happens in the Bowman’s
capsule, high pressure _____________ (water)
and _____________ from the blood through
the glomerulus and into the Bowman’s capsule
• _____________ : nutrients and water move
from the nephron tubules back into the blood
capillaries, most water is reabsorbed by the
_____________
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• _________: kidney moves specific substances
(__________________ ) back into the blood at the
proximal tubule and leaves excess solutes in the filtrate, this
forms urine
• ____________________ : reabsorb lots of water back
into the blood, the urine is then removed from the kidney
through the _____________ and into the __________
FILTRATION
Nephron tubule
REABSORPTION
H2O, other small molecules
SECRETION
EXCRETION
Urine
Capillary
Figure 25.10
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• Urine collected from the nephrons in the renal
pelvis moves through the ureter, into the
_____________ (muscular and elastic),
bladder empties urine through the _______
and out of the body.
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From blood to filtrate to urine: A closer look
• _____________ and other hormones
regulate the amount of salt and water the
kidneys excrete
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• Controlled secretion of H+ and reabsorption of
bicarbonate ions help regulate blood pH
• Secretion also includes the active transport of
drugs and poisons
• Reabsorption of salts and urea promote the
osmotic reabsorption of water
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Bowman’s
capsule
Proximal tubule
NaCl
H2O
HCO3–
Glucose and
amino acids
Distal tubule
NaCl
H2O
HCO3–
Blood
Filtrate
H2O
Salts (NaCl, etc.)
HCO3–
H+
Urea
Glucose
Amino acids
Some drugs
Some NH H+
3
drugs
and poisons
K+
H+
Collecting
duct
CORTEX
MEDULLA
Loop of
Henle
NaCl
NaCl
H2O
Reabsorption
Active transport
Passive transport
NaCl
Urea
H2O
Secretion
(active transport)
Urine (to renal pelvis)
Figure 25.11
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25.12 Connection: Kidney dialysis can be a
lifesaver
• A _____________ compensates for kidney
failure
– It performs the function of the nephrons by
removing wastes from the blood and
maintaining its solute concentration
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Line from artery
to apparatus
Pump
Line from
apparatus
to vein
Tubing made of a
selectively permeable
membrane
Dialyzing
solution
Fresh dialyzing
solution
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Used dialyzing
solution
(with urea and
excess salts)
Figure 25.12
HOMEOSTATIC FUNCTIONS OF THE LIVER
The liver is vital in homeostasis
• It assists the kidneys by
– making urea from _____________
– breaking down toxic chemicals (__________)
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• Blood from the
intestines flows
through the liver
before
distribution to
the rest of the
body
Inferior
vena cava
Hepatic vein
Liver
– This allows the
liver to adjust
the blood’s
chemical
content
Hepatic
portal vessel
Intestines
Figure 25.13
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• Skin: part of excretory system, excretes sweat
(sweat gland), which is mostly water, salt and
urea
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• Lungs: part of excretory system, excretes CO2
and H2O
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Disorders:
• _____________ : kidney(s) aren’t working,
blood is not being filtered (bad), solution is a
dialysis machine (temporary)
• ________ : due to high protein diet, causes
uric acid production and deposition in joints.
Reduce protein intake and take meds to reduce
uric acid production
• _____________ : based on diet (protein)
and water intake
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