View
220
Download
3
Category
Preview:
Citation preview
1. Name two systems we have seen countercurrent exchange in.
2. Calculate the probability of tossing three coins simultaneously and obtaining three heads. Express in fraction form.
4/1 Daily Catalyst Page 102 Osmoregulation
1. Name two systems we have seen countercurrent exchange in.
Thermoregulation and the respiratory system Vasodilation and vasoconstriction Blood and water flow in opposite directions to one
another 2. Calculate the probability of tossing three coins
simultaneously and obtaining three heads. Express in fraction form.
4/1 Daily Catalyst Page 102 Osmoregulation
Spring Break packet due Tuesday, April 7th
Email me or text me with questions Use your book and notes
Immune system on Tuesday
4/1 Class Business Page 102 Osmoregulation
Daily Catalyst Class Business Reading quiz Osmoregulation notes Quiz #26
4/1 Agenda Page 102 Osmoregulation
Name: _________ Date: 4/1 Score: _______/4 1. How do fish balance water loss? 2. In freshwater fish, why do they uptake salt
by their gills? 3. How do sharks lose excess salt? 4. As mammals, how do we excrete
nitrogenous waste?
4/1 Reading Quiz
1. How do fish balance water loss? They drinks lots of water 2. In freshwater fish, why do they uptake salt by their
gills? In freshwater, there is a lack of salt, so the fish get the
salt they need from NaCl in the water 3. How do sharks lose excess salt? Kidneys remove salt, lost in feces, and excreted by the
rectal gland 4. As mammals, how do we excrete nitrogenous waste? Urea
4/1 Reading Quiz
Homeostatic control systems in species of microbes, plants, and
animals support common ancestry.
4/1 Objective
Day after day, day after day, We stuck, nor breath nor motion;
As idle as a painted ship Upon a painted ocean.
Water, water, every where, And all the boards did shrink; Water, water, every where,
Nor any drop to drink.
The cell relies on the aqueous environment!
H2O and Solute [ ] is maintained within a narrow range
= HOMEOSTASIS
Osmoregulation and Excretion
What about waste from metabolism?
Key Point #1: Two key processes: Osmoregulation
Solute [ ] regulation by the uptake and loss of H2O
Excretion Losing nitrogen containing wastes
Key Point #1:
Osmoregulation Solute [ ] regulation by the uptake and loss of
H2O
HOW? Control MVMT of solutes from in and out of the
cell BECAUSE… Water follows solutes
OSMOSIS
44.1 Osmoregulation balances the uptake and loss of water and solutes
Key Point #2: Osmoconformer Internal environment isotonic with the environment A stable environment is essential Common in marine fish
Key Point #3: Osmoregulator Internal environment is not isotonic with
environment Must control its own osmolality Very expensive Common in freshwater and terrestrial organisms
Osmotic Challenges
Osmoregulation
Marine Fish
Most are osmoconformers Ocean is dehydrating! Drink lots of water and
gain salts by diffusion Kidneys excrete lil water
Freshwater Fish
Mostly osmoregulators Constantly gain H2O by
osmosis and lose salts by diffusion (lack of salt in the habitat)
Salt needs are lower Reduces energy cost
Bacteria Rapidly take in salt or
electrolytes through their cell membrane
Protists Vacuoles remove waste
as the H2O enters the cell membrane
The movement of salt from the surrounding water the blood of a
freshwater fish requires the expenditure of energy in the form of
ATP. Why?
Turn and Talk
Key Point #4: Most important waste is nitrogenous breakdown of proteins and nucleic acids
Most nitrogen is removed as AMMONIA (NH3) Super toxic
44.2 An animal’s nitrogenous wastes reflect its phylogeny
and habitat
Ammonia: Aquatic animals
Why? Ammonia is toxic and need access to lots of water
for dilution Ammonium ions (NH4+)
Ammonia
Urea: Common in mammals, sharks, amphibians, turtles,
and some fish Produced in the liver NH3 + CO2 to be excreted in the kidneys Low toxicity Costly
Urea
What role does the vertebrate liver play in the body’s processing of nitrogenous waste?
Think-pair-share
Uric Acid: Common in insects, land snails, reptiles, and
birds Non toxic Insoluble in water so it forms a paste VERY COSTLY! (more than urea)
Uric Acid
The kind of waste excreted, depends on the animal’s evolutionary history and habitat. Availability of H2O Environment (food sources) Reproduction Age
Who would you expect to produce more waste, endotherms or ectotherms? Endotherms eat more food and produce more waste
Influence of evolution on N2 waste
Dragonfly larvae, which are aquatic, excrete ammonia, whereas adult dragonflies, which are terrestrial, excrete uric acid. Explain.
Find a partner
What advantage does uric acid offer as a nitrogenous waste in arid environments?
Arid- dry, lack of water Uric acid has an advantage over Ammonia
and Urea because, Uric acid is nontoxic and does not need to be diluted like ammonia. Even though it is nontoxic, it is energy costly.
Find a classmate
What role does the vertebrate liver play in the body’s processing of nitrogenous waste?
Urea is produced in the liver and will travel to the kidneys where water is added (little or a lot) and the body excretes the liquid (urine)
Share Out
The excretory process: Body fluid is brought into contact with a
membrane of the excretory system Proteins and large molecules CANNOT cross the
membrane Water, salt, sugar, and amino acids CAN cross
Forms the filtrate The “good stuff” is reabsorbed by the body
(amino acids, vitamins, and glucose) Waste is released as urine
44.3 Diverse Excretory Systems are variations on a
tubular theme
The systems that perform the basic excretory functions vary widely among animal groups.
Similarity?
Network of tubules that provide A LARGE SURFACE AREA for exchange!
Network of tubules that connect to external openings
Flame cells form the “caps” Cilia
Draws water and solutes in Filtrate in the tubules Empties “urine”
Flatworms (Protonephridia)
As cilia beat, fluid is drawn into the tubules, into the bladder, and excreted outside
Tubules excrete nitrogenous waste Intake water by their skin (osmosis)
Earthworms (Metanephridia)
Kidneys function in osmoregulation and excretion! In vertebrates
Has tubules too! I mean, A LOT of tubules
Kidneys
Compare and contrast the different ways that metabolic waste products enter the excretory
systems of flatworms, earthworms, and insects.
Stop and Jot
What happens when feedback loops do not work very well? We have seen this in blood clotting, insulin and
diabetes, and now….
Example Dehydration in response to decreased
antidiuretic hormone (ADH)
After ingesting a salty meal, the blood osmolality rises. The concentration of solutes
ADH is released into the bloodstream. ADH reaches the kidney and it ATTACKS the tubules! Water is reabsorbed FROM the kidney Concentrates urine, reduced urine volume, and we
dilute our blood!
ADH
Guess what?! Yes, Negative feedback loops!
As the osmolality of water subsides, a negative feedback mechanism reduces the activity of osmoreceptors cells in the hypothalamus, and ADH secretion is reduced.
ADH
What about when blood osmolality decreases? No need for ADH
Large volume of water and dilute urine
ADH
What is the effect of a mutation preventing the production of ADH? Mutation in aquaporin's
DEHYDRATION! Urine that is large in volume and very dilute
ADH
Recommended