BIOD43H3 Lecture Notes - Lecture 3: Turkey Vulture, Hummingbird, Myocyte
Ca or Ca 2+ = Calcium
Slide 2
Previously talked about transformation of energy for locomotion but need to account for
efficiency.
But what level of efficiency?
Metabolic efficiency: proportion of potential energy transformed into mechanical work
→ not 100%, some nrg is lost as heat.
Can be 0% efficient, some goals isn’t to move muscle to move from pt A to B, but instead we
want the byproduct, heat to raise body temperature
Efficiency can also be really high in some cases but also 0,
IE: isometric contraction (flexing)
Muscles are getting warmer through nrg usage, not shortening muscles or moving
something from point A to B thus isometric contraction is 0% efficient and no effective work.
Mechanochemical efficiency: efficiency with converting chemical energy into usable
mechanical work.
Slide 3
What is a costly activity?
Slide 8
IE: Frog calling → Calling wouldn't use more energy compared to when he’s just sitting
→ But calling all night long, that low level of power input being sustained ends up being a lot
of energy expended
→ This doesn’t that he will have to do other activities such as foraging to get more nrg.’
IE: Humming bird have intense display (diving) only last few seconds and only conducted a
few times a day at most.
→ May indicate that the bird is able to maintain big machinery → Strong wings etc
But doesn’t display whether he can display an energetically costly behaviour
IE: Spider → combination of both, relatively intense display and is sustained for a relatively
long period → May be displaying to female that he can do and sustain a tough behaviour for
a long amount of time
Slide 10
Tension isn’t binary (isn’t simply on or off)
Must vary amount of force our muscle produces (not just turning muscles on and off) we
need fine tune control to respond adequately to environment.
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Variation in tension is due to morphological → different fiber types
Motor units: Ways we organize neural input regulates muscle func
Slide 12
Tuna are ram ventilators → only have water move across the gill when they move across
water → chase their preys
Groupers on the other hand gulp water to move it past their gill → surprise and ambushes
prey
Slide 13
Division of muscle fibers
There are slow muscles and fast muscles → Binary differentiation
Also how aerobic a muscle may be.
Slow oxidative fibers (type I): Have low force per cross sectional area, slow contraction
velocity, highly resistance to fatigue, with
→ high mitochondrial density & Capillary density associated with red muscle fibers
Turkey vulture: they’re soaring birds, doesn’t flap their wings and just ride thermal currents
→ Rich in this fiber type as they’re keeping muscles stretched in isometric contraction as it
isn’t force demanding → Less force than rigorously flapping wings
Think of them as red muscle fibers
Fast oxidative glycolytic (Type IIa): Best of both worlds → good force per force cross
sectional area
Fiber type associated with most flapping birds → Humming birds, ducks, animals that can
sustain flapping flight for long period of time
→ These birds can be migratory birds that are beating wings rapidly but are also sustaining it.
Fast Glycolytic (IIb) White fiber types: Burst muscle fiber type. Birds can fly to escape
predator, but cannot fly long distances.
Slide 14
SDHase is an aerobic nzm
find more resources at oneclass.com
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Document Summary
Previously talked about transformation of energy for locomotion but need to account for efficiency. Metabolic efficiency: proportion of potential energy transformed into mechanical work. Not 100%, some nrg is lost as heat. Can be 0% efficient, some goals isn"t to move muscle to move from pt a to b, but instead we want the byproduct, heat to raise body temperature. Efficiency can also be really high in some cases but also 0, Muscles are getting warmer through nrg usage, not shortening muscles or moving something from point a to b thus isometric contraction is 0% efficient and no effective work. Mechanochemical efficiency: efficiency with converting chemical energy into usable mechanical work. Ie: frog calling calling wouldn"t use more energy compared to when he"s just sitting. But calling all night long, that low level of power input being sustained ends up being a lot of energy expended.
