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28 Cards in this Set
- Front
- Back
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osmoregulartion |
processes by animals which control solute concentrations and balance water gain and loss |
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excretion: |
the process that rids the body of nitrogenous metabolites and other metabolic waste products |
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osmoregulation balances |
water gain and water loss |
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osmolarity |
the number of moles of solute per litre of solution |
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what does it mean if 2 solutions are isoosmotic? |
the two solutions have the same osmolarity |
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if 2 solutions differ in osmolarity, net flow of water will be from the _______ to the ________ solution. |
hypoosmotic (less concentrated) to hyperosmotic (more concentrated) |
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osmoconfromers |
permits it’s internal osmolarity to change |
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osmoregulators |
resists a change in internal osmolarity |
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what osmoregularity problem is encountered by marine fish such as cod? |
constantly lose water by osmosis (balance water loss by drinking large amounts of seawater, ridding themselves of salts through gills and kidneys) |
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what osmoregularity problems do freshwater fishes encounter? |
gaining water by osmosis and losing salts by diffusion (drinking almost no water and excreting large amounts of very dilute urine, salts lost by diffusion and in the urine are replenished by eating) |
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how would migration affect the osmoregulatory systems of migratory salmon? |
migrations require a reorganization of the osmoregulatory systems, physiological and anatomical remodelling (smoltification) prepares the fish to enter seawater |
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what is anhydrobiosis? |
a dormant state where their habitats dry up (life without water) tardigrades or water bears |
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what are transport epithelia? |
one or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions |
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how do marine birds remove NaCl from their blood |
nasal salt glands, use active transport of ions to secrete a fluid much saltier than the ocean, salt gland achieve a net gain of water |
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nitrogenous waste products are formed from the breakdown of which macromolecules? |
proteins and amino acids |
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3 types of nitrogenous waste |
ammonia: aquatic animals (bony fish) no ATP urea (produced from ammonia): mammals, most amphibians and some bony fish, sharks some ATP uric acid: birds, other reptiles, insects and land snails most ATP |
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advantages and disadvantages of 3 forms nitrogenous waste |
ammonia: very toxic, interferes with diverse biochemical gradients, exocytosis and enzyme function urea: costs energy to make urea, permits nitrogenous waste to accumulate with less toxicity, only effectively excreted as solutions in urine uric acid: costs even more ATP, less toxic than urea, excreted as anhydrous solid waste, conserves water |
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nitrogenous waste and their environment |
terrestrial turtles (dry areas): excrete mainly uric acid (conserves water) shelled eggs: uric acid precipitates out of solution and can be stored within an egg as a harmless solid left behind when animal hatched |
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key steps of excretory system function |
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 capillaires 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 4. excretion: the altered filtrate (urine) leaves the system and the body |
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key steps of excretory system function |
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 capillaires 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 4. excretion: the altered filtrate (urine) leaves the system and the body |
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what animals have protonephridia? |
flatworms (form a network of dead-end tubules) |
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which animals have metanephridia? |
earthworms (excretory organs that collect fluid directly from the coelom) |
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Metanephridia Figure 44.11 |
Each segment of a work has a pair of metanephridia, which are immersed in cœlomic fluid and enveloped by a capillary network. A collated funnel surrounds the internal opening. As cilia beat, fluid is drawn into a collecting tubule, which includes a storage bladder that opens to the outside. As urine moved along the tubule, the transport epithelium bordering the khmer reabsorbs most solutes and returns them to the blood in the capillaries. Nitrogenous wasted remain in the tubule and are excreted to the outside. Earthworms inhabit damp soil and usually experience a net uptake of water by osmosis through their skin. Produced dilute urine (hypoosmotic to body fluids) |
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Malpighian Tubules |
insects and other terrestrial anthropods |
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malpighian tubules figure 44.12 |
the malpighian tubules extend from dead end tips immersed in hemolymph to openings into the digestive tract. the filtration step common to other excretory systems is absent. instead the transport epithelium that lines the tubules secretes certain solutes including nitrogenous wastes from the hemolymph into the lumen of the tubule. water follows the doutes into the tubule by osmosis and the fluid then passes into the rectum. most solutes are pumped back into the hemolymph and water reabsorption by osmosis follows. the nitrogenous waste-mainly insoluble uric acid- are eliminated as nearly dry matter along with the feces. |
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malpighian tubules figure 44.12 |
the malpighian tubules extend from dead end tips immersed in hemolymph to openings into the digestive tract. the filtration step common to other excretory systems is absent. instead the transport epithelium that lines the tubules secretes certain solutes including nitrogenous wastes from the hemolymph into the lumen of the tubule. water follows the doutes into the tubule by osmosis and the fluid then passes into the rectum. most solutes are pumped back into the hemolymph and water reabsorption by osmosis follows. the nitrogenous waste-mainly insoluble uric acid- are eliminated as nearly dry matter along with the feces. |
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kidneys function in both |
osmoregulatiin and excretion |
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urine produced by each kidney exits through a _______ and is temporarily stored in the ______ |
ureter, bladder |
