Musculo-Skeletal System (topic 5) Flashcards
Define Epimysium
Thick connective tissue that wraps the muscle belly, allows for movement and carries nerves and blood cells
Define Perimysium
Connective tissue that surrounds bundles of muscle fibres
Define Fasciculi
Bundles of muscle fibres
Define Endomysium
Surrounds each individual muscle fibre
Define Slow twitch muscle fibre
Muscle fibre that uses oxygen to produce energy (high oxidative capacity); endurance based activities
Define Fast twitch muscle fibres
Muscle fibres that has high glycolytic capacity (anaerobic); speed and power based activities
Define a motor unit
The motor neuron and the group of muscle fibres that it controls
Define Innervation
A motor neurone transmits a nerve impulse or action potential to the muscle
Define the all or none law
Individual muscle fibres within a motor unit contract either fully or not at all - individual muscle fibres cannot partially contract
Define multiple unit summation
The strength of a muscle contraction can be increased by recruiting more motor units
Define wave summation
Increases tension within a motor unit; rapid stimulus without relaxation produces tetanus
Define tetanus
A smooth and sustained muscle contraction produced when a motor unit is stimulated by a series of impulses in quick succession
Define proprioceptors
Sensory receptors in muscles, tendons, joints and inner ear; detect motion or position of body or limb by responding to stimulus
What is a joint?
Where two or more bones meet and muscles act together to cause movement
What are fibrous/ fixed joints?
- Bones at an immovable joint which cannot move
- they overlap or interlock
- they’re held together by a tough fibre
- e.g the skull