the three types of cardiac muscle

skeletal (striated, voluntary), cardiac (only in the heart, striated), smooth (in the walls of hollow organs, not striated, involuntary).

anatomy of skeletal muscles (layers)

1. muscle (epimysium surrounding) 2. fascicle (perimysium surrounding) 3. muscle fibre 'myofibre' (endomysium surrounding) 4. myofibril (sarcoplasmic reticulum surrounding) 5. myofilaments (actin & myosin) no surrounding.

sarcoplasmic reticulum function

surrounds each myofibril. responsible for storing & regulating calcium.

Myosin function

thick active filament. red

actin function

inactive filament, doesn't move.

sarcomere definition/ function

actin & myosin overlap to enable muscle contraction.

motor nit function/definition

consists of a motor neuron and the muscle fibres it innervates.

action potential

the motor neuron produces an action potential (electrical impulse) which causes the release of acetylcholine (ACh) from the axon terminal.

diffusion

ACh 'diffuses' across the neuromuscular junction and binds to the ACh receptors on the sarcolemma.

depolarisation

opening the binding sites

cross bridge cycle/sliding filament theory

latent period

the muscle has lag period when when stimulated.

muscle tensions

concentric-low tension eccentric-high tension isometric-medium tension

tension relationship

the muscle is strongest when its length is at the goldilocks zone. in the middle. so myosin and actin and close, but not too close.

muscle architecture

parallel (high velocity, fibres in a row, long, lower forces) & Pennate (leaf structure built for power. high force, Low velocity).

pre stretching

temperature