Muscular Flashcards
Major muscles of the human body
Deltoid - upper shoulder Pectoralis major - Chest Triceps - Back of the arm Biceps - Front of the arm Internal Obliques External Obliques Rectus Abdominus - Abs Rectus Femoris - inner thigh Quadriceps Satorious - outer side of waste to inner side knee Tibialis Anterior Latissimus Dorsi - largest muscle Gluteus medius & maximus Gastrocnemius - calf muscle Achilles Tendon
the types of muscle fibres (give example)
Slow twitch fibres – are best suited to endurance (aerobic) activates as they:
- Contract slowly with less force
- Have an increased capacity to use oxygen - Have the capacity to contract for longer time periods
- Don’t fatigue easy
Fast twitches fibres – are best suited to high intensity (anerobic) strength and power activities as they:
- Contract rapidly
- Contract with greater force
- Have large fibre diameter
- Have the capacity to contract for only shorter time periods
Types of muscular contractions
Isoinertial contraction is a contraction when muscles are responding against a constant load where the measurement system considers acceleration and velocity.
Isometric: A muscular contraction in which the length of the muscle does not change.
eccentric: An isotonic contraction where the muscle lengthens.
concentric: An isotonic contraction where the muscle shortens
Antagonist, Agonist and reciprocal inhibition
Reciprocal inhibition is a neuromuscular reflex that inhibits opposing muscles during movement. For example, if you contract your elbow flexors (biceps) then your elbow extensors (triceps) are inhibited.
The muscle that is contracting is called the agonist and the muscle that is relaxing or lengthening is called the antagonist.
Stabilizers
In any movement, stabilizer muscles act to stabilize one joint so the desired movement can be performed in another joint
Explain size principle
The size principle states that as more force is needed, motor units are recruited in a precise order according to the magnitude of their force output, with small units being recruited first, thus exhibiting task-appropriate recruitment.
Explain all or nothing principle
When the electrical impulse reaches muscle fibres of a particular motor unit it must be over a certain threshold to stimulate contraction
- If the impulse does not reach the threshold nothing happens
- When the threshold is surpassed, a contraction is stimulated ALL fibres in the motor until will contract MAXIMULLY and at the same time
Therefore:
- For maximum contraction – ALL motor units will be activated and contract maximally
- For a sub maximal contraction – only some of the motor units will be activated and contract maximally
interactions of muscles & bones
Muscles move body parts by contracting and then relaxing. Muscles can pull bones, but they can’t push them back to the original position. So they work in pairs of flexors and extensors.
