The Human Brain

The brain weighs

• 10 pounds

• 3 pounds

• 33 pounds

• 1 pound

The brain is a part of the

• skull

• circulatory system

• digestive system

• central nervous system

What protects the brain?

• the heart

• the nose

• the skull

• all of the above

A constant stream of messages travels through the neurons inthe spinal cord, at speeds of more than ----- miles per hour

• 150

• 50

• 35

• 53

Learning new things increases the number of -----connections between -----

• brain function

• neurons

• synapses

• synapses and neurons

. Each neuron may beconnected to as many as ----- other neuron

• 11

• 100

• 10,000

• 10

Neurons are just ----

• cells

• brains

• nerves

• muscles

There areapproximately ----- of these cells in the brain alone

• 85 million

• 85 billion

• 85 thousand

• 85

Picking up a book from a table is an example of a --------

• synapse

• inaction

• involuntary action

• voluntary action

if a person touches a hot surface and burns his or her hand, this is an ------

• involuntary action

• voluntary action

• inaction

• none of the above