What is the dynamic tissue in our body that allows bones to interact with the environment?
Muscle
Muscle is controlled by the nervous system and accounts for every variable.
True or false: Stable posture means that forces are unbalanced.
FALSE
Stable posture indicates equal force.
What are the two types of tension in muscles?
- Active tension
- Passive tension
Both types affect muscle function and stability.
What are the three connective tissues associated with muscle structure?
- Epimysium
- Perimysium
- Endomysium
These tissues play roles in muscle shape and force transmission.
What is the function of the epimysium?
Surrounds surface of muscle, separates from other muscles, resists stretch
It gives form and shape to the muscle.
What is the difference between fusiform and pennate muscle architecture?
- Fusiform: Longer fibers, less force
- Pennate: Shorter fibers, greater force
Pennate muscles generally create greater force due to more fibers.
What is the pennation angle?
Angle of orientation between muscle fibers and tendon
A 0-degree angle transmits full force to the tendon.
What does the length-tension relationship describe?
The relationship between muscle length and its ability to generate force
It is affected by active and passive components.
What is isometric force?
Force utilized when muscle acts as a skeletal stabilizer
It opposes actions caused by gravity or external forces.
What does MVIC stand for?
Maximum Voluntary Isometric Contraction
It is used as an indicator of muscle’s peak strength.
What is the Henneman Size Principle?
Order of recruitment from smaller to larger motor units
Smaller motor units are recruited first for efficiency.
What is sarcopenia?
Loss of muscle tissue with advanced age
It results in a 10% decrease in strength per decade after age 60.
Fill in the blank: If you don’t use it, you lose it refers to _______.
Muscle disuse
Inactivity can lead to muscle atrophy.
What are the effects of muscle fatigue?
- Metabolic processes
- Physiological mechanisms in the neuromuscular system
Fatigue can be compensated for by increased recruitment.
What happens to muscle strength after 10 days of inactivity?
Up to 40% decline in strength
Slow twitch muscles are affected first.
What is the role of titin in muscle structure?
Helps align and stabilize fibers
It is a structural protein that contributes to muscle elasticity.
What is the force-velocity relationship in muscle contractions?
- Concentric: ↑ load = ↓ velocity
- Eccentric: ↑ load = ↑ velocity
This relationship affects how muscles generate power.
