Skeletal & Muscular Sytem Flashcards
what is the saggital plane
it lies vertically, dividing the body left and right from the medial to lateral
what’s the frontal plane
lies vertically, divides the body into anterior and posterior parts
what’s the transverse plane
lies horizontally, dividing the body into superior and inferior parts
what does flexion do
decreases the angle at a joint
what does extension do
increases the angle at a joint
what does planta flexion do
increase joint angle by moving toes further from tibia
what does dorsi-flexion do
decreases joint angle by moving toes closer to the tibia
what does horizontal flexion do
moves articulating bones away from the midline through flexion
what does horizontal extension do
moves articulating bones towards the midline through extension
what does rotation do
bone turns about its longitudinal axis
what does abduction do
moving bones away from the midline
what does adduction do
moving bones towards the midline
what’s a concentric contraction
the muscle shortens under tension, it occurs in the agonist
what’s an eccentric contraction
where the muscle lengthen under tension, occurs in the antagonist
describe the role of a motor unit
- nerve impulse is initiated in the motor neurone
- Impulse is conducted down the axon by nerve action potential
- neutrotransmitter called acetylcholine is secreted into the synaptic cleft
- if electrical charge is above a threshold, muscle fibres contract
- happens in an ‘all-or-none’ fashion
