Muscular System Flashcards
Function of ligaments
Attach bone to bone
Agonist
Muscle contracting
Antagonist
Paired muscle with agonist that relaxes
Reciprocal inhibition
Agonist and antagonist relationship
Stabilizers
Muscles that contract to allow other muscles to move
Name 2 types of muscle fibre:
Fusiform and Pennate
Define fusiform fibre
Longer fibres arranged in parallel
What are 3 pennate fibres and define them:
Uni-pennate - Fibres run off a central tendon on one side
Bi-pennate - Fibres run off a central tendon on both sides
Multi-pennate - Fibres run off a central tendon in multiple sides
Name 3 factors effecting muscle strength:
- Age
- Speed of contraction
- Fibres arrangement
- Gender
- Greater speed = Greater force
The casing around the muscle is called:
Perimysium
What are muscle fibres made up of?
Myofibrils
What does each myofibril contain? Whats the structure?
Myosin - Thick filament
Actin - Thin filament
Z-Line - Attaches actin and myosin
What causes muscles to contract?
Signal comes from the brain, through the spinal cord and into the muscle fibre telling the myosin to pull the actin to contract the muscle.
Why do muscle cramps occur?
When the body does not have the correct balance of salts.
All or nothing principle
The signal from the brain to the muscle fibre to contract has to be strong, any weaker than required and there will be no contraction.
Function of Tendons
Attach muscle to bone
Isotonic
Muscle changes length
Concentric
Shortens when contracting
Isometric
Muscle doesn’t change length
Eccentric
Lengthens when contracting
Isokinetic
Special machine where resistance changes through range of motion
What are fast twitch fibres best suited for in movement?
Suited for explosive or powerful movements
What are slow twitch fibres best suited for in movement?
Suited for slower but more sustainable movements to better use oxygen.
Explain sliding filament theory:
The theory of the muscle contraction involves myofibrils sliding across each other - Actin slides over Myosin.
