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170 Cards in this Set
- Front
- Back
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What are the advantages of gills as respiratory surfaces? |
Larger surface area Protects resp. organs Greater extraction efficiency |
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Respiratory Organ |
Required for resp of larger organisms Turned outward is a gill Turned inward is a lung |
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Respiratory organ of sea cucumbers |
Water lung Sack branching from cloaca and widening of posterior section of digestive tract Water fills the lungs and is forcibly ejected outside. I guess absorption of oxygen happens there |
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Ventilation |
Movement of oxygen through environment and to the respiratory organ Either move water over gills or move gills through the water |
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How do Necturus ventilate |
They fan their gills |
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How do mussels and clams ventilate? |
They use ciliary action to move water over the gills |
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How do crustacea, squid, octopi, and fish ventilate? |
Mostly through a mechanical pump that pumps water over the gills |
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Fish ventilation |
1. Buccal pump 2. Ram ventilation |
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Polychaete respiration |
O2 diffuses into respiratory capillaries |
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Annelid gills- Bloodworms |
O2 uptake through simple thin walled gills O2 transported through open coelomic space by RBCs- cilia and contractions of musc move fluid in coelom O2 uptake by RBCs restricted to gills |
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Annelid gills- Terebellid |
Gills confined to anterior segments Benthic, infaunal lifestyle Positioned vertically in substrate to facilitate ventilation Vent tail to head- body wall takes up O2 1st High affinity Hb in RBCs of coelomic fluid Low affinity extracell Hb in blood vessels at gills |
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Mollusc respiration |
Ctenidia are gill branches- cilia on ea gill filament Water flow is counter current to blood flow Gas exchange at gill, mantle, visceral mass Upper intertidal gastro- mantle and gills Subtidal gastro- mainly gills |
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Cephalopod respiration |
Same as rest of molluscs except mantle is elongate and venilatory current produced via muscular contractions Their Hb has highest affinity for O2 than other molluscs- max. resp efficiency Branchial heart at base of each gill |
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Crustacean gills |
Less deformable, stiffer Branchial chamber with carapace reverse flow in some crust. allows for clearing of gills 16-20% utilization of gills |
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Scaphognathite gills- crustacean |
Gill bailer Modified appendage that moves water through the gills water flows thru at base of legs, over gills, out thru base of antennae and mouth |
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Crab gills |
some crabs can hold air in gill chamber with a pool of water in the bottom, allowing gills to stay moist when crab is on land |
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Possible mechanisms behind respiratory rhythm and why fish ventilate faster and heavier during exercise. |
1.) Neurons from locomotion centers of the brain connect to respiratory centers in anticipation of movement 2.) Brain possesses some detection mechanism that triggers a respiratory response when muscular contraction occurs |
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Aquatic invert regulation of resp |
Poor regulation True reg in marine sp that live in well aerated waters Some are tolerant of low oxygen |
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Resp Reg in warm blooded vertebrates |
Ventilation precisely adjusted according to level of CO2 in blood- diving mamm more sensitive to CO2 than terrestrial Most diving is aerobic Anaerobic diving would limit the freq possible |
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Describe the graph |
B is an oxyconformer- no regulation, O2 consumption decreases with decreasing env O2 A is an oxyregulator- they maintain O2 consumption even as env O2 declines. Maintain resp rate until get to critical O2 conc, below which their resp system cannot cope. Resp declines below this point. |
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Oxyregulators |
Fish, amphibians, turtles, octopi Min level of resp must be maintained Vent increases when env O2 declines Stimulus is lack of O2- CO2 not stimulus bc conc are too low in water |
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Ram ventilation |
Most fish can do active and ram vent. As increase swim speed, there is a slowing of ventilatory movements Complete conversion to ram at 65 cm/s Work shifts from opercular muscles to swimming body muscles |
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Why might met/resp rate increase at faster swim speeds? |
1.) Shows switch from active to ram vent- faster speeds force more water over the gills 2.) Change in swimming mode (?) 3.) Drag decrease- would have to be in fusiform fish- at high speeds, get turbulent flow in boundary layer which delays streamline separation and form drag. Less drag-less energy expended (and O2 consumed) during swimming |
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How do obligate ram ventilators regulate respiration in face of declining O2 |
Bonnethead sharks seen to : 1.) Increase swimming speeds which forces more water over the gills and increases O2 uptake 2.) Increase gape of mouth so more water can flow in and then over gills- more O2 uptake |
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Resp differences between active and sluggish fish? |
Active fish have large s.a. of gills, could also have thinner gill epithelium, more RBCs and Hb, lower p50, presence of cathodal (pH insensitive) Hb and anodal Hb as backup, no Bohr effect (cathodal Hb) |
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Advantages to air breathing fish |
1. Can get air when low O2 in water 2. Can withstand periodic droughts 3. Can move over land for dispersal |
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What organs are used for air breathing? |
gills, skin, mouth, opercular cavities, stomach, intestine, swim bladder, lungs |
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What are the consequences of extended aerial exposure in eels? |
Increase in arterial CO2 and decrease in O2 Severe extracellular acidosis, reduction in RBC ph- Bohr and root effect Gradual increase in blood lactate due to anaerobic glycolysis hydrolysis of ATP stores further depresses pH |
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Swamp eel respiration |
Ventilate water until PO2 falls below 30-50mmHg Exact switch PO2 depends on acclimation history After switch, begin air breathing Acclimation to chronic hypoxia allows for higher switch PO2 and v.v. |
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Gar Respiration |
Facultative air-breather Depend on gills at low water temp, but breathe air at higher temps- b/c DO change with temp Air breathing stim by external chemoreceptors located by gills Gill vent is controlled by internal chemoreceptors |
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Lungfish Respiration |
African and S. Am. are obligate air breathers and Australian is not Obligate air breathers move into air and O2 consumption is unchanged Australian into air and arterial O2 content drops to nearly zero |
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State of cortisol research in fish |
-sparse knowledge in fish, lag behind mamm -lit biased to cort for stress, not other functions -diff methods hard to compare -binding hor reduce active hor conc -hard to ID cort as causative agent -cort mineralocorticoid function -nongenomic cort action in fish -dexamethasone cort analogue -smoltification nonstandard model cort action |
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mineralocorticoid |
Corticosteroid steroid hormones that influence salt and water balance Na retention 1a-OHB in sharks |
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Why did bass recover better in NaCl than CaCl? |
Wait for paper |
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Why do Cl- increase tolerance of striped bass for nitrites? |
Wait for paper |
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Effects of copper |
Copper kills chloride cells in gill tissue, which greatly impacts osmotic balance Cortisol reduces necrosis by copper Why? Idk |
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More cort problems/considerations |
-lipid soluble, phys effective conc may differ from actual conc bc of binding ptns -rapid nongenomic action and slow, long-lasting genomic action -housekeeping roles, present in unstressed org (maintain normoglycemia and prevents hypotension) -can interact with many other hormones |
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normoglycemic |
presence of normal amounts of glucose in blood |
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arterial hypotension |
low blood pressure in arteries |
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Gpase- glycogen phosphorylase |
Enzyme responsible for controlling rate of glycogen degredation Catalyzes phosphorylytic cleavage of glycosidic bonds within macro-glycogen molecules producing glucose-1-P molecules Known as glycogenolysis |
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Glycogenolysis |
Cleavage of glycosidic bonds in glycogen molecules to produce glucose-1-P molecules, catalyzed by glycogen phosphorylase |
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G6PDH: Glucose-6-phosphate dehydrogenase |
Enzyme in pentose phosphate pathway (pentose shunt) |
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Pentose phosphate pathway |
Metabolic pathway parallel to glycolysis. Generates NADPH and pentoses and ribose-5-P Anabolic oxidation of glucose |
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Ribose-5-P |
precursor for synthesis of nucleotides |
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G6Pase: Glucose-6-Phosphatase |
Enzyme that hydrolyzes glucose-6-P to produce a free glucose and P Completes the final step in gluconeogenesis and glycogenolysis |
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Turtle diving |
Submergence under hypoxic conditions leads to use of liver glycogen stores Use anaerobic glycolysis |
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Ways turtles can conserve liver glycogen when diving. |
-utilize glycogen from other areas- heart and brain -use more efficient fermentation pathways besides lactate -depress metabolic rate- 85% during dive |
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Problems deep diving mammals face: |
-lack of O2 -the bends -O2 tonicity -narcotic effects of gases -effect of high water pressure at depths |
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The Bends |
Nitrogen bubbles form in blood and tissues |
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How do diving mammals prevent the bends? |
-prevent gases from supersaturating in tissues -exhale @ start of dive -whales compress lungs and force air into trachea so no N can enter blood -blood flow to lung minimized during dive |
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Effects of diving in deep water with high pressure |
-Can alter chemical reactions and structure of complex molecules -affect ptn structure, ionization of weak acids, and velocity constants of chem rxns -membranes are compressed, so ATPase compresses and restricts movement and fluidity of membrane -seals and whales have enz sys that are insensitive to pressure |
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Diving response |
-bradycardia- low HR -lowers cardiac output -peripheral vasoconstriction -lower blood glucose- less blood flow -blood lactate increase-anaerobic processes |
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Types of diving |
1. Feeding- aerobic, short, can dive again immeadiately after, most 2. Exploratory- longer, anaerobic, recovery required, swim slower, lower ATP turnover |
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What to do with accumulated lactate during a dive? |
1. tolerate it, let it accumulate 2. remove and metabolize it 3. excrete it |
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How do animals tolerate lactate accumulation during a dive? |
Turtles have ptn buffering and maintain large bicarbonate stores to buffer blood and tissues. Seals also have increased buffering capacity. |
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What happens with O2 and Hb during a dive? |
Seals showed higher amounts of Hb during a dive and hematocrit increased (more RBCs). Allows for better and more efficient transport of O2 to tissues/organs during anoxic period -Large increase in RBCs likely from spleen (RBC reservoir), vasoconstriction also causes spleen to contract so RBCs injected into blood and spleen volume decreases during dive |
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Osmoconformer |
Change body fluid conc to conform with environment Ex. marine inverts |
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Osmoregulator |
Maintain or regulate its osmotic conc despite changes in env |
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Hyperosmotic |
Type of osmoreg where body fluid more conc than env freshwater fish |
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hypoosmotic |
Type of osmoreg where env is more conc than body fluid saltwater teleosts, glass shrimp |
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Euryhaline |
Animals that tolerate wide variations in salinity Estuarine organisms |
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Stenohaline |
Animals that can only tolerate a narrow range of salinities Ex. sipunculid worms, cephalopods, jellyfish |
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Describe the graph |
Conformer (blue) has linear relation with env conc, but some can hyper or hypo conform (black) by having slightly higher or lower conc. Regulators (orange) maintain their conc but can maintain it above or below env conc- hyper or hypo (left and right portions of line). |
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Describe the graph |
Osmoconformer crab transferred to dilute 58% SW Internal conc slowly lowers to match that of SW Does this by taking in water causing weight gain. Takes in water to dilute internal conc. to that of env |
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How can regulation of amino acids help org. osmoreg? |
Altering AA conc can affect internal conc . Allow for cell volume reg while preventing intracellular ionic changes that could cause perturbations in actions of metabolic enz. |
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How could utilization of AA for cell vol reg prevent ion changes that may disturb metabolic enzymes? |
idk- H+ released? CO2? acid would lower pH met enz don't work as well at low pH? |
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Explain this graph |
When crab goes from FW to SW, where it is now hypoosmotic to env and have higher water conc than env so water would shift out-see that in first few days. AA increase which raises internal conc to make it more isoosmotic to env which allows water to shift back into tissues-seen at days 4-15 |
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Explain the graph of osmoreg in 2 species of glass shrimp. |
P. paludosus is a hyperosmotic regulator that maintains conc above env. Can maintain 50% internal until env gets to about 15 ppt, it cannot regulate in this range, so its internal conc increases with env past 15. Tolerates low range of salinity- stenohaline P. intermedius is hypo and hyper, so it can always maintain internal conc of 65%- it tolerates a wider range of salinities-euryhaline |
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Effects of starfish entering dilute waters? |
- Integument softens - Increased water content - Low heat tolerance - Reduced metabolism - Will not breed in these waters |
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What organs are responsible for ion uptake? |
-Body surface- FW annelids, molluscs, & verts -Gills- crustaceans and fish -Excretory organs -Gastrointestinal tract |
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What is this image a diagram of? |
Ussing chamber- used for measuring properties of epithelial membranes Can also measure current as indicator of net ion transport across epithelium |
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Describe what is happening in the figure. |
The figure diagrams the ion uptake through the skin of a freshwater organism. Na+ diffuses into skin and is actively transported into the extracellular fluid at the basal membrane.K+ is transported into the skin as a counter ion for the antiporter. Antiporter also moved HCO3- out of body and Cl- into skin. Cl- then diffused into the ECF. |
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What are the 4 osmoreg strategies in fish? |
1.) hagfish- stenohaline, marine 2.) marine elasmo- isoosmotic to hyperosmotic 3.) marine teleost- hypoosmotic 4.) FW fish- hyperosmotic |
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Hagfish osmoreg |
-Stenohaline and marine -No reg at all -body salt conc similar to env -glomerular kidney with a single duct -only vert osmoconformer -don't need to reg bc habitat (deep ocean) is unchanging in salinity |
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Marine Elasmobranch Osmoreg |
-Internal inorganic salt conc 1/3 of SW -Retain urea and TMAO 1:2 ratio to increase body salt conc, and amino acids -makes them isoosmotic or slightly hyperosmotic |
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Marine teleost |
-Salt conc 1/3 that of SW -hypo-osmotic -must deal with water loss and salt gain -ingest SW and excrete salt - chloride cells in gills eliminate excess salts |
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Freshwater teleost |
-hyperosmotic -deal with ion loss (gill) and water gain -don't drink water (already have too much) -excess water excreted by kidneys -lots of dilute urine -chloride cells in gills actively uptake ions |
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How do euryhaline sharks go into fw? |
-Bull sharks and sawfish -when go into FW, reduce urea retained by 2/3 -reduces FW intrusion -kidneys still process a lot of water -FW rays can't retain urea so reg like fw fish |
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What info could you get about osmoreg by measuring scope for activity? |
Scope is diff btwn AMR and SMR. If fish is in osmotic env to which they aren't adapted, will expend more energy to maintain homeostasis. SMR will be increased which would decrease scope. Less energy available for other processes. But- maybe could increase AMR too, which could give same scope. Maybe looking for changes in SMR and AMR better than scope. |
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Explain the figure |
Scope of euryhaline fish at diff salinities. Larger scope means more E available, so less E spent on osmoreg. Largest scope at 20ppt, so that is where they are at osmotic eq. Lots of extra E available. Lower scope at 5 and 30ppt, so more E used for osmoreg and less extra E available. |
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Describe this figure. |
-Alpha Cl cell of marine teleosts -Na/K ATPase to get high Na conc in blood which allows for transport of Cl into cc and cotransport of Ca into blood -Cl diffuses out into SW through channels -Na diffuses out through leaky junctions btwen cc and accessory cell -Allows for removal of excess Na and Cl ions |
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Describe this figure |
-Beta Cl cell of freshwater teleosts -Bc Na and Cl continuously lost to env, must be exchanged. Na exchanged for H+ and NH4+. Cl exchanged for HCO3- -Na moved into blood via Na/K ATPase -Cl moved into blood via channels on basolateral membrane of cc and channels in pavement cell |
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Describe the figure. |
Figure of shark rectal gland- gets rid of excess salts -Na/K ATPase to get Na into ECF and K into gland -Na then into gland by Na/Cl/K cotransporter -Cl into lumen of gland via channel -Na into lumen via junctions btwn cells Gland then excretes NaCl solution out of body -K back into ECF via channels to maintain gradient |
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How is the rectal gland hormonally controlled? |
-By vasoactive intestinal peptide hormone VIP -Binds to receptor and activates adenyl cyclase which uses ATP to produce cAMP which turns on the Na/K ATPase |
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Describe the osmoreg strategy of the crab |
Lives in swamps and mangroves and can tolerate brief excursions into SW. Retain urea like elasmo to be slightly hyperosm to env. Slow water influx- helps to form urine- excrete conc urine |
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How do air-breathing marine vertebrates osmoreg? |
Essentially terrestrial in their regulation except drink sea water and their food has high salt content. -marine plants and inverts with more salt -marine fish with less salt-those that eat it have less of a salt problem -excrete salt as conc as SW or dehydrate |
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Sea snake osmoreg |
Kidneys can't prod conc urine Have salt glands that open into the mouth with Na/K ATPase activity and excretes conc NaCl solution when in SW -Some sp must find FW or dehydrate -Possibly why distribution so patchy-has to be by FW -Some sp prod dilute urine |
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Sea turtle osmoreg |
Kidneys can't prod conc. urine Have lachrymal salt glands with specialized secretory cells in corners of eyes so it looks like they are crying salt. |
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How does lachrymal gland work? |
Salt gland of sea turtles -Basolateral membrane has Na/K pump to actively transport Na -Moves salt from blood into the gland -Gland excretes it as a conc solution |
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Leatherback sea turtle osmoreg |
They consume mainly jellyfish which are isoosmotic to SW- enormous salt load -Very large salt glands -Injection of epinephrine and methacholine dramatically reduced rate of Na excretion |
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Loggerhead sea turtle osmoreg |
Hatchlings lose 12%wt from water loss when emerge from nest -Drink SW and return to wt in few days w/o feeding -Exp sealed mouth and cloaca in 2 trtmnts- mouth open, able to increase wt, both closed unable to increase wt--drink SW |
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Diamondback terrapin osmoreg |
SW terrapins with higher osm pressure bc higher urea accumulation in bladder- become isoosmotic -SW terrapins with isoosmotic urine -FW terrapins with hypoosmotic urine -bladder red water loss in SW terrapins |
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Marine iguana osmoreg |
Feed underwater on marine algae and drink SW-large salt load -Nasal glands secrete conc NaCl solution -Most water from food |
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How is water lost and gained? |
Water loss- evaporation from body (not aq), from resp surfaces (aq w/lung), feces and urine Water gain- drinking, uptake via body surface from water, water from food, metabolic water |
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How is water flux measured with tritium? |
Inject water labelled with tritium and follow decline of isotope activity over time -Declines bc of excretion, evaporation, input of unlabelled water via met, eating and drinking |
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What are the assumptions for estimating water loss? |
1. body water volume remains constant 2. rates of water influx and efflux are constant 3. Isotope only labels water in body 4. Isotope leaves body only as water 5. specific activity of isotope in water lost from body is same as in body water 6. lab or unlab water from env doesn't enter body via skin or resp surfaces* |
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What happened in Dr. P's bonnethead water flux exp? |
Injected shark w tritiated water, blood sample after 2 hrs then after 24 hrs -specific activity of tritium dramatically declined over 24 hrs- almost none left -why? likely due to stress- cat increase perfusion at gill so water can flux quickly |
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Equation of metabolism |
C6H12O6 + O2 --> 6CO2 + 6H2O |
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Doubly labeled water technique |
Inject water w tritium and 18O -18O declines bc loss of body water and loss of CO2 -tritium declines bc loss of body water only Diff can tell how much CO2 produced- directly related to met rate -Det from respiratory quotient Know how much label left body as water and CO2- diff gives CO2 prod and met rate |
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Respiratory Quotient |
Ratio of O2 used in metabolism to CO2 eliminated- estimation of total met rate -Typically btwn 0.7 and 1 -Differs based on diet- need to know |
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How do you determine CO2 produced via doubly labeled water? |
CO2= amount of activity decline of 18O - amount of activity decline of 3H |
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What are the 4 respiratory pigments with examples? |
1. Hemoglobin- mam birds rept amph fish 2. Hemerythrin- peanut worms, duck leeches, and bristle worms 3. Hemocyanin- spiders, crustaceans, snails, slugs, octopuses, and squid 4. Chlorocruorin- some marine worms |
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Blood functions |
Transport nutrients transport metabolites transport excretory products transport gases (O2 and CO2) transport hormones transport heat transport leukocytes coagulation transport ions- maintain internal env- pH force- hydraulic movement, filtration |
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Why are respiratory pigments important? |
Increase the amount of O2 that can be carried |
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Colloidal osmotic pressure |
osmotic pressure caused by molecules that are not dissolved into the solution. Colloidal solution is one where the solvents do not fully dissolve the solutes and they are not homogenously mixed. Higher coll osm press means more undissolved molecules |
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Contrast resp pigments enclosed in blood cells vs dissolved in plasma |
Molecular weight of pigments is higher when dissolved in plasma than when enclosed in blood cells. -This allows for an increase in size rather than number of pigments which decreases colloidal osm pressure which influences passage of fluid thru capillary walls and ultrafiltration. -env can be diff in cell than plasma- control |
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Explain Hb situation of Icefish (Chaenichthyidae) |
They have no Hb.
They live in very cold waters that have high DO Low metabolism b/c ectothermic Some don't even have myglobin Don't need it bc don't need as much O2 and there is plenty around |
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Explain Hb structure and function |
Hb is a tetramere- made of 4 subunits- 2 alpha and 2 beta polypeptide chains Each subunit has a porphyrin ring with an iron molecule that allows for binding to O2 There is cooperativity in binding such that when O2 binds to one subunit, it causes a conf change in shape so the next subunit has a higher affinity for O2, and so on with each subunit |
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Hemoglobin vs myoglobin |
Hb is a transporter of O2 with a sigmoid shaped dissociation curve due to cooperativity. Mb is a storage molecule with no cooperativity. P50 of Mb is lower than that of Hb meaning that Mb has a higher affinity for O2 than Hb |
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O2 dissociation curve |
Graph with O2 conc on x axis and % sat of pigment on y axis. Can look at p50 to see affinity of pigment for O2 |
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Factors affecting O2 dissociation curve |
1. temperature 2. pH 3. CO2 4. organophosphates |
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Temperature effects of O2 dissociation curve |
High temperatures weaken the bond btwn Hb and O2 Increases p50 |
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Effects of CO2 and pH on O2 dissociation curve |
Increase H+ and Hb structure changes which affects affinity for O2 Increase in CO2 decreases pH Low pH causes Bohr shift and root effect |
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Bohr shift |
Hb has reduced affinity for O2 Causes dissociation curve to shift to the right Results in a higher p50 Due to low pH |
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Root effect |
Hb has reduced capacity for binding O2 Causes dissociation curve to shift down Due to low pH |
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Effect of organic phosphates on dissociation curve |
ATP and GTP reduce affinity of Hb for O2 If have ATP, then don't need O2 for cell respiration at the moment Some fish can lower ATP in hypoxic waters to increase O2 uptake |
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What is the use of multiple Hbs? |
There can be variants. One can be cathodal (ph insensitive) and one can be anodal (ph sensitive) -Cathodal can still load O2 even when entire body acidified during intense exercise Some can also be insensitive to temperature and organophosphates -temp insensitive important in endothermic fish so don't offload O2 when warm up |
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Hb of young/larval/fetal organisms |
Most Hb in young have higher affinity for O2 than adult -fetal Hb in humans -oviparous elasmos -tadpoles- Hb nearly pH insensitive -Coho salmon fry- larger Bohr shift bc more resp |
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How does activity affect dissociation curve? |
More active fish have larger Bohr shift, curve to the right to help unloading of O2 into muscles that have O2 debt b/c of exercise. Less active fish or fish in low O2 water have small Bohr and curve to left to facilitate loading of O2 b/c in short supply |
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Hemocyanin |
Copper based, dissolved in hemolymph monomeric or polymerized cooperativity Bohr or reverse Bohr Diff types, changes during dev, and seas var in O2 binding, temp reduces affinity |
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Reverse Bohr effect of Hc |
Increase in affinity of Hc for O2 when pH is low Species that show reverse Bohr are typically in hypoxic waters where they would have a build-up of acids Amphiuma and horseshoe crab -both bury in hypoxic mud -reverse allows ATP in these conditions |
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Hemerythrin |
Iron bound to amino acid chains Mostly no cooperativity No Bohr always enclosed in cells temperature modulates affinity 3 polymorphs with diff affinities |
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What are the polymorphs and affinities of hemerythrin? |
1. Myohemerythrin- muscle, high affinity, low p50 2. Coelomic- coelom, mod affinity, higher p50 3. Vascular- blood, low affinity, high p50 O2 cascade from external env to muscle No cap perfusion in muscle, so high affinity may compensate |
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Chlorocruorin (Greenish Hb) |
Polychaetes green when oxygenated similar to Hb some sp with mix of Cc and Hb high cooperativity, low O2 affinity, high Bohr |
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Poikilotherm |
Internal temperature varies considerably; maintain temperature by behavioral means- basking |
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Homeotherm |
Maintains thermal homeostasis |
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Q10 |
The increase in the rate of a process when the temperature is raised by 10 degrees C Ex. Q10=2, rate doubles |
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Q10 Equation |
Q10= (R2/R1)^(10/T2-T1) Where, R1= rate of reaction before temp increase R2= rate of reaction after temp increase T1= initial temperature T2= T1+10, increased temperature |
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If Q10=3, then what type of increase would there be from 0 to 30 degrees Celsius? |
30 degree increase 0-10: 3x rate increase 0-20: 3 * 3= 9x rate increase 0-30: 3 * 9 = 27x rate increase |
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Q10 to compare studies: Study 1: resp rate= 125 @ 15degrees Study 2: resp rate= 350 @25 degrees |
Q10= (R2/R1)^(10/T2-T1) Q10=(350/125)^(10/25-15)= Q10= (2.8)^(1) Q10=2.8 |
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What are the highest temperatures that can be tolerated? |
50 degrees C is the highest to carry out a complete life cycle- desert pupfish Some larvae and eggs can tolerate 100 deg C Many animals, especially aquatics, die at cooler temperatures than this, though Upper intertidal animals must be adapted to high temps |
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Lethal temperature |
Temperature at which 50% of organisms die |
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Describe the graph |
Illustration of lethal temperature. Temperature (x axis) that corresponds with 50 % survival (y axis) |
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How can you determine the high temp tolerance of animals? |
Subject organisms to various temperatures and record the time it takes for 50% to die. |
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Explain this graph |
Determination of high temperature tolerance. Subject organisms to various temps and recording time until 50% die. As temp increases (y axis), the time to 50% death decreases. I think the axes should be switched. |
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What is something to keep in mind/control for with thermal tolerance studies? |
Exposure time should be equal or controlled for. Longer exposure times will result in decreased survival |
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What fish has lowest heat tolerance? |
Arctic and Antarctic icefish Upper tolerance is 6 deg C |
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What causes heat death? |
1. denaturation of proteins at 45-55 deg C -polymeric enz can depolymerize 2. thermal inactivation of enz at rates that exceed rates of formation 3. inadequate O2 supply at high temps 4. differential effects on interdependent metabolic pathways- 1 rxn in pathway more sens than other 5. high temp can change lipid bilayer and functional properties of membrane |
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What are the strategies to endure extreme cold weather? |
1. Freeze susceptibility- avoid ice formation 2. Freeze tolerance- tolerate ice formation in body |
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Supercooling |
Possible strategy for freeze susceptibility Supercool below the point where the body might freeze Can occur when nuclei for ice formation aren't present |
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Freezing point depression |
Process in which adding a solute to a solvent decreases the freezing point of the solvent Ex. anything in water Water has high heat capacity and high FP, so when anything is added to water, get FPD |
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What is the function of antifreeze compounds? |
Glycoproteins lower the freezing point, so it takes more to freeze. They also prevent addition of water molecules to crystal lattice of ice-bind to ice surfaces exposed to water to protect it from further binding Thermal hysteresis- Icefish MP: -1 C, FP: -2.2 C |
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Thermal hysteresis |
Difference between the melting point and freezing point. Water FP- 0 C, Ice MP- 0 C It is easier to melt than it is to freeze. Rather than just depressing FP, it also raises MP |
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Antifreeze action |
Side chains on antifreeze disaccharide molecule bind to ice crystal lattice |
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Antifreeze structure |
All work by binding to face of ice crystal lattice 1. AFGP 2. AFP l 3. AFP ll 4. AFP lll |
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What is going on in this graph? |
Displays the thermal hysteresis (degrees btwn FP and MP) of diff sp and diff conc of AFP General trend- as AFP conc increases, thermal hysteresis increases Sea raven with highest hysteresis, Atlantic cod with lowest |
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AFP mechanism |
AFP binds to prism faces thru dipolar and H bond interactions Results in ordering of water dipoles in the field of AFP helix dipoles, ice can't grow Ice still grows on unordered basal plane then AFP binds to new ice Results in bipyramid ice growth |
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Peripheral defense hypothesis AFP |
Antifreeze in gill, where ice formation is most likely. May block ice crystal penetration to interior of body and body fluids. Some antarctic fish have AFPs in integument |
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Problem with antifreeze |
1. Still get ice growth, but can't get as widespread, stay small and needlelike 2. Once ice forms, can't get rid of it because it never gets warm enough to melt it |
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How do organisms tolerate freezing? |
Some intertidal invertebrates can withstand freezing of 70% total body water All freezing in extracellular fluid, so cells shrunk and distorted but contained no ice crystals |
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Ice-nucleating agents |
Trigger ice formation in ECF at relatively high temperatures to draw water out of cell which causes dehydration and lowers the freezing point of the cell Prevents ice formation inside cell Freezing tolerant animals |
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Acclimitization |
Changes in temperature tolerance of an animal with its' natural climate |
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Acclimation |
Changes in temperature tolerance of an animal induced by artificial stimuli- in a lab setting |
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Explain the figure |
The bullhead catfish shows seasonal fluctuation in thermal tolerance as shown by the TL50 in diff seasons. Lowest TL50 is at 28 C in winter, highest is at 36 C in summer |
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Describe the figure |
The area of the polygon shows the thermal tolerance of the fish. Fish acclimated at lower temps have lower TL50, fish acclimated at higher temps have high TL50 for upper limits and v.v. for lower limits Goldfish has large area/tolerance, salmon area/tolerance is small |
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Do freshwater or marine species have higher thermal tolerances? Why? |
Freshwater fish have higher thermal tolerances than marine fish. FW fish are in smaller bodies of water than marine (large ocean), therefore they experience larger temperature fluctuations and need a larger range |
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Explain the graph |
Changes in some rate (ventilation here) with an increase in temperature. Increase rate with increased temp is normal Partial compensation for temp when higher temp only has slightly higher rate Complete comp when rate doesn't change w temp Overcomp when higher temp has lower rate |
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Heat balance equation |
Hs = Htot +/- Hr - Hc - He Hs= heat storage Htot= met heat prod Hr= heat exchange by radiation Hc= heat conduction to env He= evaporation |
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Heat balance equation of aquatic animals |
Hs = Htot - Hc I think No heat exchange by radiation bc in water No evaporation bc in water Main heat loss by conduction to env thru gills Can increase heat by met or reduce loss thru conduction |
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Benefits of endothermy |
- rates of vital processes relatively stable - stability of neural function - remain active at night in low temps - select habitat not based on thermal limits - faster recovery from exercise - more chem rxns, more musc output - increases rate of O2 delivery from cell boundary to mito by Mb |
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Costs of endothermy |
- high basal met rate (SMR) - must acquire more food - pop densities must be lower since need more food |
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Brown adipose tissue (BAT) |
Thermogenic tissue- chemical bond energy only used for heat Mito of BAT produce no ATP or NADH - possess short circuit of mito ATP synthesis Present in dolphins- like blubber for insulation but also head prod |
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Other ways of producing heat |
Shivering- contract musc to split ATP and release heat Futile cycles- no net effects, just heat prod from rxns |
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Heat balance adaptations in frigid waters |
1. Have lower body temp in extremely cold waters 2. decrease metabolic rate 3. insulation |
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How are marine mammals adapted to frigid waters? |
Mainly through insulation. Body temp is same as mammals in warmer env, and met rate doesn't change even in freezing water. Insulation Insulation outside skin surface Outer portions same temp as core |
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Heat exchangers of flippers and flukes of seals and whales |
Bc lack blubber and poorly insulated, high potential for heat loss Heat xchanger- counter current arrangement of vessels Artery brings warm blood to flipper, veins out of flipper and take warm blood from artery. If want to keep flipper warm, collapse veins next to artery so artery stays warm in flipper. Blood leaves via other veins away from artery |
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Why do people say that red muscle of salmon sharks is similar to mammals? |
Because they are so adapted to endothermy and warm body temperatures, their red muscles only work at elevated temperatures (20-30 C). At lower temperatures, muscles have less power White muscles still work at low temperatures |
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What are the effects of having a warm stomach? |
Speeds digestions rxns by trypsin and chymotrypsin so digest ptns in 1/3 time Vmax increased Km constant |
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What is Km in lineweaver-burke plot? |
Substrate concentration that produces 1/2 Vmax |
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What is Vmax in lineweaver-burke plot? |
Maximum reaction velocity |
