Chapter 2- Part 6 Flashcards
What are the factors which affect muscle strength?
Fibre arrangement, muscle fibre recruitment, muscle fibre type, speed of contraction, gender and age
How does muscle fibre recruitment affect muscle strength?
When maximal force is required, all the fibres in all motor units must be recruited
How does fibre arrangement affect muscle strength?
Multipennate muscles are the strongest pennate muscles and fusiform muscles develop the least strength
How does muscle fibre type affect muscle strength?
Fast-twitch fibres are able to generate greater strength than slow-twitch fibres, and fast twitch B fibres are stronger than fast twitch A fibres
How does gender affect muscle strength?
Muscles of the same cross-sectional area in males and females are equally strong, however females muscles generally have smaller cross-sectional areas than males
How does age affect muscle strength?
Muscles tend to be at their strongest between the ages of 20 and 30, and then progressively deteriorate by about 1% per year after this
Why do muscles deteriorate over time and how can this be arrested somewhat?
Our bodies synthesise less protein required for the building of muscles, which can be arrested by performing regular weight and resistance exercises
How does speed of contraction affect muscle strength?
As the speed of contraction increases, the amount of force a muscle can generate proportionally decreases
What are muscle fibres made up of?
Myofibrils, which contain many units known as sarcomeres
What are myofibrils divided into?
Myofilaments, known as actin and myosin
What are myosin and actin?
Myosin = Thick Filament Actin = Thin Filament
What does the sliding filament theory involve?
The myofilaments sliding across each other, as the actin sides over the myosin
What does the sarcoplasm contain?
Mitochondria, myoglobin, fat, glycogen, PC, ATP and enzymes
What are mitochondria?
The powerhouse, where oxygen combines with other substances to produce energy
What is myoglobin responsible for?
The transport of oxygen from the blood to the mitochondria
