Muscle Review (take 2)

Myofibrils are composed primarily of

• actin and myosin

• ATP and ADP

• Troponin

• Tropomyosin

Neurotransmitters are stored in vesicles within

• motor units

• motor neuron endings

• myofibrils

• motor end plates

The enzyme cholinesterase causes acetylcholine to

• be secreted from the motor end plate.

• form cross bridges.

• bind to actin.

• decompose.

Skeletal muscles are responsible for moving

• The heart

• The skeleton

• the pancreas

• The brain

Which of the following muscle types are voluntary?

• Skeletal

• Cardiac

• Smooth muscle

What are the three types of muscles?

• voluntary, smooth, cardiac

• cardiac, skeletal, nervous

• cardiac, smooth, skeletal

• smooth, cardiac, stomach

Which cell organelle provides energy for muscle contraction?

• lysosome

• nucleus

• endoplasmic reticulum

• mitochondria

During a muscle contraction, cross-bridges from between what two structures?

• Actin and myosin fibers

• neuron and muscle

• mitochondria and actin

Vesicles in the motor neuron store what substance?

• cholinsterase

• acetylcholine

• calcium

• curare

When recruitment occurs, the number of motor units being activated

• increases

• decreases