 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 7 th  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

Outside 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)