Muscle Bundle = group of muscle fibers (muscle cells) that function together and are bound together by fascia (connective tissue). Examples: biceps brachii,

Muscle Bundle = group of muscle fibers (muscle cells) that function together and are bound together by fascia (connective tissue). Examples: biceps brachii,trapezius, pectoralis major.

Origin

Insertion

Belly

Prime mover = muscle that provides the primary movement at a joint. In thisExample: Biceps brachii

Synergist = muscle that Assists the prime mover.In this case the brachialis

Antagonist = muscle that opposes The prime mover. In this example:Triceps brachii.

Bone

Tendon

Fascia

Fascicle

Muscle Fiber

Sarcolemma

SarcoplasmicReticulum

TransverseTubule

SarcomereZ-line

Sliding Filament Hypothesis

Z-lineActinMyosinZ-line

Myosin HeadsFully Stretched

Partially Contracted

Fully Contracted

Sarcomere Shortening

Myosin Head in the relaxed conformation

Tropomyosin coveringBinding sites

ATP

CaCaCa

Motor neuron Axon

Neuromuscular junction

Vesicle containingNeurotransmitter

(acetylcholine)

Transverse tubuleCa2+ active Transport pump

Ca2+Ca2+

Motor Unit = motor neuron and the muscleCells that it stimulates

Motor neuron Branches to Stimulate 4 cells Different neuron branches

to stimulate 8 different cells

Neuromuscular Junction

Motor neuronaxon

NeuromuscularJunction

Vesicles containingNeurotransmitter(acetylcholine)

Sarcolemma(muscle cell membrane)

Neuromuscular Junction