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

Osmoregulation in bacteria, fish, and protists.

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

The movement of water Passive transport (no ATP) High to low concentration

Osmosis

OsmosisOutside the cell Inside the cell

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

Brine Shrimp

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

What advantage does uric acid offer as a nitrogenous waste in arid environments?

Turn and Talk

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

Why are no freshwater animals osmoconformers?

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)

Excretory organs open internally to the coelom Coelom??

A body cavity

Earthworms (Metanephridia)

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

Mammalian Excretory System

25% of

blood

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)

What is a diuretic?

Produced in the hypothalamus Stored in the pituitary gland

Antidiuretic Hormone

Function: To conserve water loss in urine

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

These mutations can lead to DIABETES (more on this later)

What else can lead to decreased ADH amounts? Alcohol

Excessive water loss and dehydration (hangover)