Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOL241 > Topic 9 - Locomotion > Flashcards

Topic 9 - Locomotion Flashcards

1
Q

What is the organization of skeletal muscles

A

Tendons connect muscles to the bone

Muscles are a bundle of muscle fibres

Muscle fibres are composed of myofibril with dark A bands and light I bands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Each muscle cell runs the

A

entire length of a muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the structure of Myofibrils

A

consist of alternating thick (myosin) and thin(actin) filaments arranged along the length of the myofibril

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a sarcomere?

A

the functional unit of skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the sliding filament model?

how do muscles contract

A

Muscles contract when the myosin filaments pull the opposing actin filaments toward each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the crossbridge cycle and what is ATP’s role?

A

ATP binds to myosin causing the cross-bridge to release.

As ATP is split into ADP and P, ATP hydrolysis cocks myosin into position

Myosin attaches to actin to form cross-bridge (high energy configuration)

Myosin releases ADP and P causing working stroke - myosin head pivots and bends as it pulls on actin filament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do muscles generate force flashback?

A

More force when the number of cross-bridges between actin and myosin in sarcomere increase

More force when number of muscle cells in tissue increase (bc more muscle = more sarcomeres)

More force when length of the muscle tissue increases (bc more sarcomeres)

More force when muscle contracts more slowly (rapid contraction decreases number of cross-bridges)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does metabolic rate differ for maximum and sustained? (sprinting vs long distance)

what are the limitations on energy production?

A

Sprint = 10m/s Ultramarathon = 5m/s

Because there are limitations on energy production such as the limited rate of ATP production and delivery of O2 to muscles takes time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the two types of muscle fibres and what are they used for

A

Slow Twitch (Type 1) - longer duration, or constant contractions with less force

Fast Twitch (Type 2) - fast and short bursts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain Slow Twitch (1) muscle fibres

A

Aerobic oxidation respiration
high mitochondria
high myoglobin
high vascularization
low glycogen
LOW POWER, ENDURANCE
dark meat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain Fast Twitch (2) Muscle fibres

A

anaerobic glucolusis
low mitochondria
low myoglobin
low vascularization
high glycogen
HIGH POWER, BURSTS
white meat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the physiological limitations on MRmax or MRsus

order of energy sources

A
  1. we have pools of stored ATP in our cells that provide instant energy, but they are used up fast
  2. we have PCr which is a backup pool of ATP
  3. when PCr and ATP reserves are used up, we have glycolysis to being quickly making ATP for activity
  4. Eventually oxidative phosphorylation will kick in
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

in what order are energy methods used

A

ATP, PCr, Glycolysis(anaerobic, lactic acid), oxi phosph(aerobic), oxi phosph (triglycerides)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When can MR max be equivalent to MR sus?

A

During long activities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to metabolic rate before, during, and after exercise

A

at REST, MRmax is at RMR
DURING EXERCISE: MR increases
there is O2 debt - use cellular pools of ATP/PCr and produce lactic acid,
AFTER EXERCISE, MR lowers back down to RMR during revovery metabolism - cellular pools of ATP and PCr are replenished, lactic acid is removed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does MRmax scale with mass

A

ACTIVE MRmax is log curve, facing down
On log scale, positive slope line

MASS SPECIFIC is log curve facing up
On log scale, negative slope line

17
Q

How does metabolic scope change for endo and ectotherms

A

it is roughly the same - same slope, endotherm is slightly higher

potential to increase MR from RMR to MRm is similar (scope)

18
Q

How is locomotion measured from an energy perspective

A

Mass-specific Metabolic Rate

Cost of Transport

19
Q

What is mass-specific metabolic rate

A

energy required to move 1 unit mass of an organism over 1 unit of time

Units: kJ/kgh

20
Q

What is Cost of transport (CoT)

A

energy required to move 1 unit mass of an organism over 1 unit distance

Unit: kJ/kgkm

21
Q

What factors affect locomotion

A

intertia
momentum
drag

22
Q

Inertia

A

tendency of mass to resist a change in motion

23
Q

momentum

A

tendency of a moving mass to sustain velocity

24
Q

How does inertia and momentum change with mass

A

Increase as mass increases

25
Q

What is drag

A

force generated in the opposite direction of an animals movement but the density/viscosity of the medium

Drag increases with mass and velocity

26
Q

What are the forces acting on a runner

A

Gravity downwards
Drag in front - force generated in opposition to thrust
Thrust behind - energy needed for forward motion
Muscle action up - supports mass

27
Q

How does mass affect runners

A

The cost of starting is higher for the heavier runner: higher MR max when starting

Why is mass-spec MRmx higher in mouse?
shorter muscles
it is more expensive to contract short muscles (less force generated-

Velocity, smaller runner reaches top speed quickly then plateaus. bigger runner gets to higher top speed

28
Q

How does velocity affect runners

A

velocity increases, limbs move faster –> faster muscle contractions, more nergy

small runners have to work hard to move fast because shorter muscles

as velocity increases, more energy can go towards generating forward motion - momentum increases, less contact with ground (less energy loss)

29
Q

What are the forces actin on a swimmer to move forward

A

Gravity down (negligible for acativity budget)
Buoyancy up
Thrust forward (energy needed)
Drag backward (biggest cost, density of water greater than air, body shape reduces drag.

30
Q

Why is drag a major force acting on swimmers

A

Viscous forces - skin friction drag (bc water has high cohesive properties and clings to skin)
Inertial - pressure drag

For a fish, skin friction drag is limited but there is higher pressure drag as larger organisms create turbulance

single cell organisms, skin friction drag is high but pressure is low

31
Q

How can you minimize drag in water?

A

Shape!

32
Q

How does mass and velocity affect swimmers

A

Swimmers work hard to overcome inertia (bc viscous environment), larger swimmers have less skin friction drag

As velocity increases, muscles contract faster, more energy needed

Small swimmers work hard to move faster because shorter muscles

As velocity increases, pressure drag increases - energy expense rises sharply with velocity to fight pressure drag

33
Q

For swimmers, what is the effect of mass on CoT

A

as log mass increases, CoT decreases

34
Q

Why do larger swimming organisms have lower cost?

A

They have large muscles, ability to generate more force, lower skin-friction drage

As drag increases, shape adaptations lower CoT

35
Q

Why do small swimmers live in viscous environment

A

In viscous, intertial forces are negligible, never go fast enough to generate pressure drag

Instead, many adapt to have shapes that allow them to catch the current

36
Q

What are the forces acting on a flier to move forward?

A

Gravity down (important and low velocities
Thrust forward
Drag backward (more important at high velocity)
Lift - force generated that counters gravity

37
Q

How does mass affect fliers

A

Higher mass, means harder to fight against gravity
small insects aren’t affected much

Fliers must overcome drag
Larger organisms work harder to overcome drag. smaller fliers swim through air due to higher relative density

38
Q

How does velocity affect fliers

A

Higher velocity, limbs move faster (the muscles contract faster and more energy is required)

smaller fliers work hard to move fast - continually beat wings

Larger fliers can glide to reduce energy expense, but wingspans give more lift

AS VELOCITY INCREASES, lift and drag increase
energy expense to fight gravity decreases
BUT energy expense to fight drag increases

39
Q

Give a summary of animal locomotion

A

Gravity is negligible for swimmers
Fliers generate lift to overgome gravity
Runners fight gravity with every step

BIOL241 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions