Other animal's respiratory systems Flashcards
Main fish respiration
gill respiration predominates (aquatic resp)
Teleost supplemental breathing
swim bladders: used mainly as a hydrostatic organ, assumes an accessory respiratory function in a few fish
highly vascularized anterior stomach or oral cavity
vascularized skin (works in both air and water)
primitive actinopterygains (ray-finned fish) breathing
and most sarcopterygians (lobe-finned fish) possess lungs
in addition to gills for respiration
Teleost gill arch structure
In vertebrate embryos, there are 5 branchial arches; in fishes 4 are involved in support of the gills (#1 → jaws)
TELEOST GILL ARCH STRUCTURE:
Blood flow proceeds from Afferent Artery → Capillary Net (in Gill Lamella) → Efferent Artery (Vein)
Exchange of gases occurs in capillary network in gill lamellae; water and blood flow in opposite directions over lamellae = Countercurrent Exchange
Look at the diagram of teleost gill arch structures.
for real.
Control of water flow: how do fish gill arches use rakers
cartilaginous or bony structures attached to gill arch and directed anteriorly
act like shutters to control flow of water over gills; several muscles are associated with gill arch –
these regulate flow over gills by controlling position of rakers and filaments.
Resting condition and active condition of rakers
Resting Condition = adductor muscles pull individual filaments together so separate filaments stay separated
Active Condition = abductor muscles pull individual filaments apart so separate filaments come together, water passes over gills more slowly so that oxygenextraction efficiency increases
Describe the fish gill gas exchange barrier
Simple squamous epithelium lines gill lamellae.
Diffusion barrier consists of 2 thin simple squamous epithelial layers plus a shared basal lamina between them (same situation as in lung).
Function of pillar cells
help hold lamellae apart
endothelial lining of capillaries in gill lamellae
Gas exchange in amphibians and reptiles (differences with mammals)
lungs predominate
respiratory system similar to mammalian system (lungs with bidirectional flow)
differences include a lesser number of tube divisions and much less surface area available for gas exchange
they can get away with less surface area since less oxygen is required for metabolism than in endothermic organisms
Describe cutaneous respiration in amphibians
Requires moist skin, thus amphibians are restricted to environments with relatively high humidities
Epidermis consists of a thin stratified squamous. The underlying dermis is highly vascularized.
Diffusion is slower than in lung due to thicker diffusion barrier
Most amphibians utilize cutaneous respiration to some degree.
Usually more important for getting rid of CO2 than for loading oxygen. However, it is important for both in some groups, particularly the lungless salamanders, which use cutaneous respiration for all their gas exchange.
What are external gills in amphibians?
External Gills are essentially modifications of integument.
2 cell/basal lamina complex is diffusion barrier (as in lungs and internal gills)
(filaments with a capillary core extend outside, with skeletal muscle at the base to move em around)
Describe the bird lung air sac system:
what direction does air flow?
where does gas exchange take place?
what type of “current system” is it?
Respiratory System of birds contains a complicated Air Sac System.
Lungs are spongy, rather than sac-like.
Air sac system allows unidirectional flow of air through the lungs; gas exchange takes place in air capillaries that open to a tube (parabronchus) through which air flows in one direction.
Blood flow in the bird lung is via a Crosscurrent Mechanism relative to air flow.
Functions similar to a countercurrent mechanism to provide more effective oxygenation than with bidirectional flow.
This makes birds more effective at extracting oxygen from air and explains their success at high altitudes.
