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Lecture Exam Monday• 100 point exam
• covers lectures, assigned readings
• 8-12 short answer questions; 4-6 pts ea– complete, concise answer– ex: definition; short description
• 3-5 longer questions; 10-15 pts ea
• Finish by 2:55--budget time
• Power Point lectures on blackboard• Chapters: 1, 2, 12, 13, 3, 14, 4, 15, 5
end
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Advantage of Bohr Effect
TissuesGills
blood circulation
pH lowerpH higher
pCO2 higherpCO2 lowerlactic acidno lactic acid
end
pH?
pCO2?
lactic acid?
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Teleost Heart:
sinus venosusatrium
ventricle
bulbus arteriosus
end
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Teleost Heart:
sinus venosusatrium
ventricle
bulbus arteriosus
endrelax
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Teleost Heart:
sinus venosusatrium
ventricle
bulbus arteriosus
endcontract
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Conus arteriosus--Myxini, Ceph., elasmobranchs, gar
heartto gills
end
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time
Pre
ssur
e (m
m m
erc.
)
0
60
ventricle
bulbus arteriosus
end
Effect of bulbus arteriosus on blood pressure
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Buoyancy strategies
1. Low density compounds
2. Lift generated by swimming
3. Reduction of heavy tissues
4. Swim bladder (air bladder)
end
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1. Low density compounds:
Advantages/disadvantages
Substance Specific GravityBone 2.0Muscle 1.05Cartilage 1.1Freshwater 1.002 @20CSaltwater 1.072 @20CLipids 0.9-0.92Squalene 0.86
end
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2. Lift generated by swimming:
lift
lift
thrust
sharks Advantages/disadvantagesend
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hammerhead shark
end
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sandbar shark
end
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3. Reduction of heavy tissues
Eurypharynx pelecanoides
deepwater fishes
Advantages/disadvantagesend
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umbrella mouth gulper
end
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umbrella mouth gulper
end
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4. Swim bladder
• low density
• adjustable
• most osteichthians
• lost secondarily in some species
end
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Two types of swim bladders:
• Physostomous– pneumatic duct– soft-rayed teleosts--herrings, salmonids,
catfishes, cyprinids, eels, etc.
• Physoclistous– blood/circulatory system– spiney-rayed teleosts--Acanthopterygii,
sunfishes, perch, most marine fishes
end
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Effects of depth on swim bladder volume
• pressure increases 1 ATM/10m
• swim bladder must be adjustable
• Physostomous fishes adjust volume by gulping or spitting air.– mostly shallow water species– gas-spitting reflex– gulp air at surface
end
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Physoclistous inflation/deflation
• circulatory system--source of gases
• rete mirabile (wonderful net) --inflation
• oval window--deflation
• Problem: fish need greater pressure in swim bladder than is achieved by equilibrium with blood gases
end
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Oxygen equilibrium—swim bladder inflation
DO
hemoglobin
plasma gaseous O2O2 O2
O2
gills
blood
rete
water swim bladder
How are high
pressures achieved?
end
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Counter-current multiplication system
afferent blood
efferent blood
O2hemepO2
O2heme pO2
pO2
swim
bla
dder
O2heme pO2
lactic acidBohr & Root
1
Diagram of basic functional unit of rete(inflation)
end
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Function of Rete Mirabile
1. Hemoglobin saturated with O2 (O2 heme)
plasma O2 low (p O2)
end
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Counter-current multiplication system
afferent blood
efferent blood
O2hemepO2
O2heme pO2
pO2
swim
bla
dder
O2heme pO2
1 2
lactic acid
end
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Function of Rete Mirabile
2. Lactic Acid Secretions heme dumps O2 to plasma pO2 diffuses into swim bladder to equil.
end
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Counter-current multiplication system
afferent blood
efferent blood
O2hemepO2
O2heme pO2
pO2
swim
bla
dder
O2heme pO2
lactic acid
1 2
3
end
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Function of Rete Mirabile
3. Multiplying effect: pO2 diffuses from efferent capillary to afferent cap. Longer capillaries yield more efficient exchange of oxygen, higher pressures
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O2O2
1. Steady supply of oxygen in
2. Little or none leaves
3. PO2 accum. in plasma
4. Diffusion into SB
Summary of what happens to O2
end
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Physoclistous swim bladder
• Pressures up to 300 ATM in some deep sea fishes
• Gases mostly O2, some CO2 and N2
• Guanine crystals in SB wall reduce permeability• Deflation occurs at oval window
– dense bed of capillaries on SB wall
– gasses diffuse into blood
– mucus layer covers window during inflation
end
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Summary:• Diffusion of O2; controlled by structure & function
• Relationship O2 bound to hemoglobin versus O2 in plasma
• Effect of pH on affinity/capacity of hemoglobin for O2 (Bohr & Root)
• Counter-current multiplier– length of capillaries
– counter-current flow of blood
end