Locomotion and Exercise Flashcards
What are the two kinds of fluid flow?
Laminar Flow
Turbulent Flow
Which kind of flow increases the cost of locomotion?
Turbulent flow
How can animals reduce drag? (2 ways)
1) orientation
2) streamlining
What are two types of drag?
1) Friction drag
2) Pressure drag
What part of the object determines how much friction drag there is? What is the main determinant of how much friction drag there is? What is one application of reducing this?
- BOUNDARY LAYERS
- Viscosity of the fluid
- Swimsuit designs reduced friction drag
What does a Reynolds number describe? How is it defined?
The Reynolds number describes whether inertial effects or viscous effects dominate.
Re= velocity of movement* linear dimension of object* density of fluid/ viscosity of fluid
A large Reynolds number means…
That inertial effects dominate
The cost of locomotion is greatly increased under ______________
Turbulent flow conditions
If we have a swimmer and a flier who are the same size, what has a higher reynolds number?
Swimmers have higher Reynolds numbers
What is an importantly law that governs flight (name and state it)? How do wings take advantage of this?
Bernoulli’s Principle: A faster moving liquid produces less pressure than the same fluid moving at a slower speed.
Wings take advantage of this with their shape (longer surface on top makes fluid travel faster=less pressure above)
What do we call the shape of a wing?
Camber
What is one metric that we use to measure bird wings (name and define)
Wing aspect ratio: A ratio of wingspan to wing surface area
What can we say about the wing aspect ratio of birds depending on bird size. Why is this?
Larger birds have a higher aspect ratio (longer, narrower wings) because it is more efficient for soaring. Little birds have a lower aspect ratio (shorter, wider wings) because its more maneuverable.
What is another metric describing wings and weight?
Wing loading: the weight of a bird divided by the area of its wing.
Discuss the advantages and disadvantages of wing loading, with an example for high and low
High wing loading and aspect ratio is advantageous for soaring because of low metabolic cost (albatross). Lower wing loading and aspect ratio is advantageous for thermal soaring birds because they need to have a tighter turning radius to stay in the updraft (vulture)
Name 4 adaptations/behaviors of birds that swim:
1) Increased muscle mass (heavier)
2) Exhale before diving
3) Patting down feathers to expel air and reduce volume
4) Higher wing loading (shorter wings b/c easier to generate thrust in water than in air)
Name 2 adaptations/behaviors of fish that fly:
1) Large pectoral/pelvic fins
3) high aspect ratio and high wing loading
How do fish increase their buoyancy? Why is this advantageous?
With swim bladders! It is energy efficient to have buoyancy.
What fills the swim bladder? What is this connected to? What empties the swim bladder? What is this connected to?
Gas gland fills (connected to liver). Oval window empties (connected to heart).
How does the gas gland fill the swim bladder?
Metabolism of GLUCOSE results in LACTATE formation, CO2 production, and a PROTON increase, resulting in more O2 coming off of hemoglobin and entering the swim bladder.
So, we’d say the gas gland has a high/low pH
low!
What is the world’s fastest fish? How fast can they swim?
Sailfish. 68 m.p.h.
What are three important musculoskeletal factors that influence locomotion? With examples
1) Arrangement/distribution of fibers with different functional properties (e.g. red oxidative fibers along side of fish, white glycolytic above and below)
2) Selective activation of different muscle types (red vs. white fibers)
3) Attachment of muscles and organs to skeleton (e.g. turtles are very efficient)
Why are turtles so efficient?
The top shell keeps the shoulder in place, and the bottom shell holds the gut up. They also use lots of slow muscle!
What are the three types of levers? Which is fastest, and which most powerful? What differentiates the three types?
Class I lever (fastest), Class II lever, Class III lever (most powerful)
The key metric is the ratio between the length of weight from the fulcrum and the length at which force is applied from the fulcrum
What differentiates lions and cheetahs?
Lion has the muscle attached farther from the fulcrum, so more of a powerful joint, whereas cheetah muscle is attached close to the fulcrum, so it is a faster lever.
What is a humans, dog’s, and cheetah’s top speed?
25 mph
40 mph
64 mph
What are two things that determine speed?
1) Leg strength (force generated)
2) Leg swing speed
What are three adaptations that allows cheetahs to run fast?
1) Rotary gallop (legs churn in a circular motion)
2) Flexible back (allows for long stride and longer foot contact with ground)
3) Leg swing speed (very fast!)
Describe a cheetah’s legs
Light lower leg to reduce swing speed, but powerful upper leg to generate force
What is the most important factor for force generation?
How long the foot is in contact with the ground
Describe the factors that affect a sprinter’s speed
1) Leg swing speed is even across the board for most humans: not something we can really change
2) Hitting the ground harder (generates more force). Mostly from the calf
3) Exert the same force over a longer period (maximize the time that feet are in contact with the ground)
What is one adaptation that spiders have evolved to save energy? How does it work?
Elastic sclerite: stretches when leg bends, then recoils with the stored energy!
What do kangaroos do to conserve energy?
Change in gait (4 legs to 2) takes advantage of elastic energy storage in the tendons of the legs
How does a horse optimize energy output as it wants to move faster?
Walking, trotting, and galloping all have an optimum speed. It chooses the one which is most energetically favorable (metabolic optimum) for a desired speed.
How do snakes move?
By making selective friction/contact with the surface
How do seals minimize energy?
By gliding whenever possible