Muscle Review Flashcards
(10 cards)
Muscle contraction theory: how do the filaments slide
- Ca2+ bind to the regulatory proteins on thin filaments and exposed and binding sites, allowing the micron heads on the thick filaments to attach
- Each cross bridge pivots, causing thin filaments to slide towards the centre of the sarcomere
- Contraction occurs in the cell short
- During a contraction across bridge attaches and detaches several times.
- ATP provides the energy for the sliding process which continues as long as calcium ions are present.
What is a graded response
Different degrees of skeletal muscle shortening
Each muscle fibre will either fully contract or won’t, all or nothing
Graded responses are produced in what two ways
- Changing the frequency of muscle stimulation
- Changing the number of muscle cells being stimulated at one time
Types of skeletal muscle fibres
Type 1 slow oxidative
Type 2A fast oxidative glycolytic
Type 2B fast glycolytic
Type 1 SO
Uses glucose through oxidation
Small and red
Slow and weak
Fatigue resistant
Aerobic
First to be recruited
Typically for posture and support and endurance
Type 2A FOG
Uses glucose through oxidation and glycolytic
Larger and white
Fast and strong
Aerobic and anaerobic
Recruited 2nd
Endurance and strength (long distance running)
Type 2B FG
glycolysis only
Largest and fastest and strongest
Fast to fatigue
Anaerobic
Recruited last
Quick rigorous movements like weightlifting
Length tension ranges
Outer range
Midrange
Inner range
Muscle tone
State of continuous partial contractions
Developmental aspects of muscular systems
Exercise helps retain muscle mass and strength
As we age muscle mass decreases and we become more sinewy
Extremely vigorous exercise results in hypertrophy
No exercise causes atrophy
Muscles must be exercised regularly
Muscle control is achieved in a superior inferior and proximal distal direction
