Anatomy: Neuromusclar junction and Sacromere

The two proteins that are attached to the actin myofilament are

• myosin and troponin

• collagen and myosin

• toponin and tropomyosin

• albumin and hemoglobin

The organelle in the axon terminal that contains the neurotransmitter

• mitochondria

• vesicle

• sarcoplasmic reticulum

• myofibrils

What area of the sarcomere is where actin is found only?

• A band

• Zline

• H zone

• I band

ACh that diffuses across the synaptic cleft attach to

• receptors on the sarcolema

• troponin on the actin molecule

• the sarcomere to stimulate contraction

• myosin heads to form the crossbridges

What occurs when ATP attaches to the myosin head?

• A crossbridge is formed

• myosin detaches from actin

• tropomyosin covers the active site on actin

• myosin does a powerstroke

The region where a motor neuron comes in close contact with a muscle cell

• neuromuscular junction

• joint

• sarcolemma

• sarcomere

Why do muscles need ATP?

• to move calcium

• to make neurotransmitters

• for actin and myosin to contract

• they don't need ATP

The gap between the axon terminal of a motor neuron and a skeletal muscle cell is

• sarcoplasm

• sarcolemma

• synapse

• synaptic cleft

When a muscle contracts

• myosin molecules get shorter

• actin molecules elongate

• actin slides over myosin

• actin and myosin get shorter

Makes up the thick filament

• actin

• myosin

• troponin

• tropomyosin