ANPH Muscular system: PART 1

What neurotransmitter initiates muscle contraction?

Acetylcholine (ACh)

What ion is released to start contraction?

Calcium (Ca²⁺)

What is a motor unit?

One motor neuron and all the muscle fibers it innervates

What is motor unit recruitment?

What is motor unit recruitment?

What is the origin of a muscle?

Stable, proximal attachment

What is the insertion of a muscle?

Mobile, distal attachment

What is an agonist?

Prime mover that causes the main action

What is an antagonist?

Opposes the agonist

What is a synergist?

Assists the agonist

What is a fixator?

Stabilizes joints during movement

rectus

Fibers run parallel to the midline

maximus

Largest muscle

deltoid

Triangular shape

flexor

Muscle causes flexion (decreases joint angle)

pectoralis

Located in the chest region

biceps

Muscle with two origins