Lecture Exam Monday

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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 255--budget time
• Power Point lectures on blackboard
• Chapters 1, 2, 12, 13, 3, 14, 4, 15, 5

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Advantage of Bohr Effect
blood circulation
Tissues
Gills
pCO2?
pCO2 higher
pCO2 lower
lactic acid?
lactic acid
no lactic acid
pH?
pH lower
pH higher
end
3
Teleost Heart
sinus venosus
atrium
bulbus arteriosus
ventricle
end
4
Teleost Heart
sinus venosus
atrium
bulbus arteriosus
ventricle
end
5
Teleost Heart
sinus venosus
atrium
bulbus arteriosus
ventricle
end
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Conus arteriosus--Myxini, Ceph., elasmobranchs,
gar
to gills
heart
end
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Effect of bulbus arteriosus on blood pressure
Pressure (mm merc.)
ventricle
time
end
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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)

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1. Low density compounds
Substance
Specific Gravity
Advantages/disadvantages
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2. Lift generated by swimming
sharks
Advantages/disadvantages
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hammerhead shark
end
12
nurse shark
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13
sandbar shark
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3. Reduction of heavy tissues
Eurypharynx pelecanoides
deepwater fishes
Advantages/disadvantages
end
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umbrella mouth gulper
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umbrella mouth gulper
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4. Swim bladder

• low density
• adjustable
• most osteichthians
• lost secondarily in some species

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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

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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

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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

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Oxygen equilibriumswim bladder inflation
hemoglobin
How are high pressures achieved?
DO
plasma
gaseous O2
water
swim bladder
blood
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Counter-current multiplication system
Diagram of basic functional unit of rete
(inflation)
O2heme ? ?pO2
O2heme?
1
pO2?
pO2?
swim bladder
O2heme ? ?pO2 ?
end
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Function of Rete Mirabile

• 1. Hemoglobin saturated with O2 (O2 heme)
• plasma O2 low (p O2)

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Counter-current multiplication system
O2heme ? ?pO2
O2heme?
1
2
pO2?
pO2?
swim bladder
O2heme ? ?pO2 ?
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.

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Counter-current multiplication system
O2heme ? ?pO2
O2heme?
1
2
pO2?
pO2?
swim bladder
O2heme ? ?pO2 ?
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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Summary of what happens to O2

• Steady supply of oxygen in
• Little or none leaves
• PO2 accum. in plasma
• Diffusion into SB

O2
O2
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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

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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