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Biology 2672a: Comparative Animal Physiology. Final review lecture. The Final Exam. 9 am December 8 th Talbot Hall Gym 2 hours If you are sick (etc) Take documentation to the Dean’s counsellors – they will contact me. If in doubt, sit the exam then see the Dr. The Final Exam. - PowerPoint PPT Presentation
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The Final Exam9 am December 8th
Talbot Hall Gym2 hours If you are sick (etc)
Take documentation to the Dean’s counsellors – they will contact me.
If in doubt, sit the exam then see the Dr.
The Final Exam73 QuestionsCovers everything from Lecture 2
(Krogh Principle etc) to Lecture 24 (Diving mammals) Including animal ethics, freezing
frogs, hibernation, migration and bird song
Includes labs (c. 3-5 questions) No overt weighting on any part of the
course
The final exam~40 simple definition-type
questions~10 harder single-part questions5 fun graph questions (multiple
parts)
The Make-up7 pm (in the evening!)Monday 12 JanuaryWill include written answers, as
per the course outline Format will be sent in advance to
those writing the make-up If you can’t do the make-up, the
next exam will be in December 2009
How your mark is calculatedAdded up (by the computer) and
rounded to the nearest integerNearest integer to (e.g.) 69.45 is
69 (sorry) I DO give 89, 79, 69 I DON’T give marks for arbitrary
reasons (so please don’t ask)
Important things to rememberREAD THE QUESTION!READ THE ANSWER!LOOK AT THE GRAPH! Just because something sounds
the most scientific doesn’t mean it is true I’m very good at generating
meaningless jargon!
TodayFive topics
Control of vasomotor tone Freshwater/saltwater fish Malpighian tubules Concentrating urine Freezing frogs
Local controlMyogenic stretch responseParacrine control
e.g. release of NO Responses to local conditions and
traumaEvents in muscle cell
viagra example
Central controlEndocrine (Hormonal)
e.g. Adrenaline (Epinephrine) Response depends on receptor densities, so same
hormone has different effects through body
Also vasopressin and angiotensinNeural
Sympathetic nervous system Usually chemically mediated.
From Fall 2007 Final ExamThe release of Epinephrine by
the adrenal glands is an example of paracrine control of vasomotor tonea) Trueb) False
Chloride cellsWater
Blood
Apical(Mucosa)
Baso-lateral(serosa)
Pavement cell
Lots of mitochondria
Fig. 26.6
Export of Chloride is driven by a Na+ gradient
Box 26.2
Na+ actively pumped out of cell by Na+,K+-ATPasePotassium remains at equilibrium because of K+ channels back into blood
Active removal of Cl- leads to an electrochemical imbalance that drives Na+ out of blood via paracellular channels
Box 26.2
Chloride cell summaryTranscellular transport of Cl-
Driven by Na+,K+-ATPase (requires energy)
Paracellular transport of Na+
Ionoregulation accounts for ~3-5% of resting MR in marine teleosts
Salt Water Fresh Water
Drinking Lots
Urine Little, concentrated
Ion flux Passive into fish; active out of fish
Na+,K+-ATPase Na+ into bloodstream
Tight junctions No
Cl- Transcellular transport driven by Na+ gradient
Na+ Paracellular driven by electochemical gradient
NaCl uptake summaryExchange for CO2
Na+ via electrochemical gradient Cl- via HCO3
- antiport
Very dilute urine gets rid of excess water without losing too much salt
Salt Water Fresh Water
Drinking Lots Little
Urine Little, concentrated Copious, dilute
Ion flux Passive into fish; active out of fish
Passive out of fish, active into fish
Na+,K+-ATPase Na+ into bloodstream
Na+ into bloodstream
Tight junctions No Yes
Cl- Transcellular transport driven by Na+ gradient
Transcellular via HCO3- antiporter (driven by H+ pump)
Na+ Paracellular driven by electochemical gradient
Transcellular driven by electrochemical gradient (set up by H+ pump and Na+,K+-ATPase)
From Final Exam, Fall 2007 In gills of a freshwater-acclimated
fish, where is the Na+,K+-ATPase pumping Na+ ions?
a) From the chloride cell into the bloodstream.
b) From the chloride cell into the surrounding water.
c) From the bloodstream into the chloride cell.d) From the surrounding water into the
chloride cell.e) From the surrounding water into the
bloodstream.
From final exam, Fall 2007 As well as an increase in Na+,K+-ATPase
activity, what else would you expect to happen as a fish moves from fresh to salt water?
a) The closure of gap junctions between pavement cells.
b) Increased activity of the Cl-/HCO3- antiporter in chloride cells.
c) Expression of chloride channels on the apical (mucosal) surface of the chloride cells.
d) Removal of K+ channels from the basal (serosal) surface of the chloride cells.
e) Increase in gill surface area.
Haemolymph
K+ Channel
Proton pump generates electrochemical gradient Requires ATP
K+ follows via electrogenic transporter
Lumen
V-ATPase (H+ pump)
Haemolymph
Cl- Channel
Lumen
V-ATPase (H+ pump)
Cl- follows K+ gradient
Water follows osmotic gradient into tubule lumen
Aquaporin
Malpighian tubules summary Active transport sets up ion gradients
Proton pump; K+, Cl- Water follows Passive transport of nitrogenous
wastes, amino acids etc. down electrochemical gradients
Active transport of large molecules Alkaloids, proteins etc.
Water and solute reabsorptionUrine from tubules is dilute and
contains lots of things the insect doesn’t want to lose
Reabsorption of water and solutes in hindgut/rectum Determines final concentration of
the urine
Final exam, Fall 2007Chloride ions pass from the
haemolymph to the lumen of the Malpighian tubule largely via the Principal cells.a) True.b) False.
New Question Chloride concentrations are high in the
lumen of the Malpighian tubule because...a) Active transport of chloride ions from the
haemocoel by the stellate cells.b) The chloride ions follow an electrochemical
gradient set up by sodium pumping in the principal cells.
c) The chloride ions follow an electrochemical gradient set up by proton pumping in the Principal cells.
d) All of the above.e) None of the above.
Bowman’s capsuleUltrafiltration,Production of primary urine
Loop of Henle
Thick segment of descending loop of Henle
Re-absorption of sugars, amino acids, water
Thin segment of descending loop of Henle
Thick ascending loop of Henle
Thin ascending loop of Henle
Collecting DuctUrine out, concentration of definitive Urine
Salt Re-absorption
Fig. 27.6
Concentration of urine Occurs in collecting
ducts Driven by osmotic
gradient across kidney
Both urea and salts Can be
manipulated by altering permeability of collecting duct to water
Fig. 27.14a
Concentrating UrineBigger concentration gradient =
higher maximum concentration of urine
Longer loop of Henle (i.e.: relatively thicker medulla) = longer concentration gradient = higher maximum concentration of urine
Modulating urine concentrationModulate permeability of
collecting duct to water Permeable
Concentrated urine Antidiuresis
Impermeable Dilute urine Diuresis
Final exam Fall 2007A longer loop of henle allows for
a shorter concentration gradient, increasing kidney tubule efficiency.a) True.b) False.
Final Exam, Winter 2007 Which change is primarily responsible
for the shift in production from concentrated to dilute urine?a) Increased absorption of amino acids by
the descending loop of Henle.b) Decreased absorption of amino acids in
the descending loop of Henle.c) Increased permeability of the collecting
duct.d) Decreased permeability of the collecting
duct.
To freeze a frog…Freezing initiated
Massive conversion of glycogen to glucose (liver) and circulation around body (Glycogen phosphorylase)
Dehydration of major organs (water relocated to the coelom and lymph system)
• Protein Synthesis slows to 1% • Pumps & channels closed • Energy Production slows to 5% • Energy Utilization slows to 2%• Few ‘SAP’ kinases activated • Gene ‘inactivation’ (mRNA)• Few Genes activated
• NRF-2 (= more antioxidants, especially GST)
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