nervous system

Your brain is a soft organ.

• True

• False

Select two ways that your brain is protected from injury.

• skull

• a hat

• liquid

• spinal cord

Your brain is about the size of a ___________________.

• grape

• walnut

• basketball

• grapefruit

How many neurons are in your brain?

• hundreds

• thousands

• millions

• billions

What is a neuron?

• a bone in your spinal cord

• a blood vessel in your brain

• a nerve cell

• a stroke

Select the three main parts of the brain.

• cerebellum

• spinal cord

• brain stem

• cerebrum

• liquid

What is the largest part of the brain?

• brain stem

• medulla

• cerebrum

• cerebellum

If you lose the feeling in a body part, you may have become __________________.

• sleepy

• paralyzed

• comatose

• stroke

A blocked blood vessel in the brain can lead to a __________.

• kidney infection

• stomach ulcer

• lung infection

• stroke

Which part of the brain helps your muscles work together?

• cerebrum

• cerebellum

• brain stem

• medulla